Dissertationen zum Thema „Electronic interface circuits“

A piezoelectric energy harvesting (PEH) system can harvest electrical energy from ambient vibration energy. In a PEH system, the interface rectifier circuit is critical because it converts AC from the output of piezoelectric harvester to DC that can power the load. Hence, improving the efficiency of the interface circuit can directly increase the efficiency of the entire PEH system; consequently, more power can be harvested. Commonly used interface circuits in PEH systems, such as full-bridge and voltage- doubler rectifiers,lead to relatively simple circuit implementations but they show serious limitations in energy-harvesting efficiency. Several innovative solutions have been reported to improve the efficiency of the interface rectifiers, such as ‘switch-only’ and ‘bias-flip’ techniques [7]. Such solutions utilize additional switches or switched inductors to speed up and even quickly reverse (flip) the voltage on the rectifier input to the desired voltage-level and condition for energy transfer, ultimately improving the overall efficiency of the energy harvesting. However, such techniques rely on accurate timing and synchronization of the pulsed switches every time the current produced by the piezoelectric harvester changes polarity. This thesis studies and investigates the impact of the non-ideal switching effects on the energy efficiency of the switch-only and bias-flip interface rectifiers in a PEH system, by theoretical derivation and experimental simulation.

La thèse explore la récupération d'énergie à petite échelle, en se concentrant sur les circuits de récupération d'énergie électrostatique. Elle vise à convertir l'énergie ambiante en électricité pour alimenter de manière durable des dispositifs électroniques et des capteurs, notamment dans des endroits éloignés ou inaccessibles.Cette technologie pourrait remplacer les batteries traditionnelles, qui souffrent de fuites, de capacité limitée et de sensibilité aux fluctuations de température. Elle prolonge la durée de vie des dispositifs et réduit la nécessité de recharges fréquentes, ce qui est crucial pour l'Internet des Objets (IoT). Les technologies de récupération d'énergie soutiennent l'autonomie et la flexibilité des déploiements IoT, réduisant les coûts de maintenance et permettant une surveillance en temps réel et une maintenance prédictive.La thèse analyse l'état de l'art des circuits de récupération d'énergie électrostatique, en se concentrant sur leur efficacité et leur mise en œuvre pratique à travers des diagrammes QV. Les circuits à cycle QV rectangulaire, bien que simples, sont moins efficaces, tandis que les circuits à cycle QV triangulaire offrent de meilleures performances mais sont plus complexes à mettre en œuvre.Une approche innovante combine les avantages des deux types de circuits, proposant une technique semi-passive où la charge et la décharge du transducteur sont synchronisées avec le mouvement structurel, utilisant des commutateurs contrôlables pour maintenir des cycles triangulaires. Cet équilibre entre simplicité et efficacité est une contribution clé de cette recherche.La thèse explore également différents types de transducteurs pour la récupération d'énergie électrostatique. Les transducteurs MEMS offrent une haute précision et une miniaturisation, mais rencontrent des problèmes d'efficacité à haute fréquence. Les condensateurs à base de polymères atteignent une haute capacitance mais ont des pertes d'énergie importantes dans le transducteur lui-même. Les condensateurs battants convertissent efficacement l'énergie vibratoire mais nécessitent une conception mécanique précise. Les Condensateurs Métalliques Accordables, utilisés dans des circuits résonants, sont simples à mettre en œuvre et ont des pertes d'énergie modérées (dans le transducteur lui-même), ce qui en fait une option fiable pour les circuits développés. Ainsi, le Condensateur Métallique Accordable est choisi pour valider les circuits développés.Un aspect particulier de la thèse est l'exploration de l'élément photocapacitif, utilisant des matériaux sensibles à la lumière pour convertir l'énergie lumineuse en électricité. Initialement conçu comme un condensateur variable, les expériences ont montré que cet élément fonctionne principalement comme un générateur de courant lorsqu'il est exposé à la lumière. Des tests avec le circuit doubleur de Bennet ont révélé que le transducteur génère du courant sans tension de polarisation appliquée, suggérant un mode de fonctionnement différent qui pourrait être exploré davantage.La recherche introduit la méthode SCDI (Charge et Décharge Synchronisées sur Inductance), équilibrant simplicité et efficacité dans la conversion d'énergie. Cette méthode synchronise les cycles de charge et de décharge à travers une inductance, améliorant la conversion des vibrations mécaniques en énergie électrique. Les tests ont montré que la méthode SCDI pouvait convertir environ 1 µJ d'énergie par cycle (avec un composant de stockage de 60V), nécessitant des transducteurs à faibles pertes pour un transfert d'énergie efficace.S'appuyant sur la méthode SCDI, la thèse présente la technique SCDIP (Charge et Décharge Synchronisées sur Inductance avec Cycle Positif), utilisant uniquement un cycle QV positif pour améliorer encore l'efficacité. Cette méthode réduit les pertes d'énergie dans le transducteur, améliorant significativement les performances de récupération d'énergie par rapport à la méthode SCDI
The thesis explores small-scale energy harvesting, focusing on electrostatic energy harvesting circuits. It aims to convert ambient energy into electricity to sustainably power electronic devices and sensors, especially in remote or inaccessible locations.This technology could replace traditional batteries, which suffer from leaks, limited capacity, and sensitivity to temperature fluctuations. It extends the lifespan of devices and reduces the need for frequent recharges, which is crucial for the Internet of Things (IoT). Energy harvesting technologies support the autonomy and flexibility of IoT deployments, reducing maintenance costs and enabling real-time monitoring and predictive maintenance.The thesis analyzes the state of the art in electrostatic energy harvesting circuits, focusing on their efficiency and practical implementation through QV (charge-voltage) diagrams. Rectangular QV cycle circuits, although simple, are less efficient, while triangular QV cycle circuits offer better performance but are more complex to implement.An innovative approach combines the advantages of both types of circuits, proposing a semi-passive technique where the transducer's charge and discharge are synchronized with structural movement, using controllable switches to maintain triangular cycles. This balance between simplicity and efficiency is a key contribution of this research.The thesis also explores various types of transducers for electrostatic energy harvesting. MEMS transducers offer high precision and miniaturization but they face efficiency issues at high frequencies. Polymer-based capacitors achieve high capacitance but they have lot of energy loss on the transducer itself. Flapping capacitors efficiently convert vibrational energy but require precise mechanical design. Adjustable Metal Capacitors, used in resonant circuits, are simple to implement and they have moderate energy loss (on the transducer itself), making them a reliable option for the developed circuits. Thus, the Adjustable Metal Capacitor is chosen to validate the developed circuits.A particular aspect of the thesis is the exploration of the photocapacitive element, using light-sensitive materials to convert light energy into electricity. Initially designed as a variable capacitor, experiments showed that this element functions primarily as a current generator when exposed to light. Tests with the Bennet doubler circuit revealed that the transducer generates current without an applied bias voltage, suggesting a different operating mode that could be further explored.The research introduces the SCDI method (Synchronized Charge and Discharge on Inductance), balancing simplicity and efficiency in energy conversion. This method synchronizes charge and discharge cycles through an inductance, improving the conversion of mechanical vibrations into electrical energy. Tests showed that the SCDI method could convert about 1 µJ of energy per cycle (with a 60V storage component), requiring low-loss transducers for efficient energy transfer.Building on the SCDI method, the thesis presents the SCDIP technique (Synchronized Charge and Discharge on Inductance with Positive Cycle), using only a positive QV cycle to further improve efficiency. This method reduces energy losses in the transducer, significantly enhancing energy harvesting performance compared to the SCDI method

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Orientador: Jacobus Willibrordus Swart
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
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Resumo: O trabalho intitulado Integração de Sistema Transceptor de 60 GHz para Aplicações Sem Fio de Interface Multimídia de Alta Definição (Wireless HDMI) foi realizado na empresa STMicroelectronics (França), no departamento de P&D de Tecnologia / CAD Central e Soluções, como requisito para a obtenção do título de mestre. O objetivo deste trabalho foi de pesquisar e propor uma integração de sistema do tipo Sistema no Empacotamento (SiP ou System in Package) a nível industrial, com o desenvolvimento de um Módulo de Múltiplos Chips (MCM ou Multi-Chip Module) de camadas cerâmicas com tecnologia Cerâmica Cossinterizada sob Alta Temperatura (HTCC), integrando componentes de diferentes tecnologias - um circuito integrado CMOS 65 nm, um circuito integrado monolítico de micro-ondas (MMIC) de Arseneto de Gálio (GaAs) comercial e antenas IPD (Dispositivo de Integração Passiva) de vidro. Além disso foram desenvolvidas técnicas de projeto de integração na tecnologia HTCC, atendendo-se às regras para fabricação e montagem industrial. Utilizaram-se no projeto ferramentas software de projeto de simulação elétrica e eletromagnética, resultando no módulo com área de 13 x 8 mm2 e 1,12 mm de espessura incluindo os componentes. Nas linhas de transmissão do sinal a 60 GHz e de banda base foram medidas perdas de inserção de 1,0 dB/mm e 0,6 dB respectivamente. A antena integrada no módulo apresentou um ganho mínimo de 6 dBi (de 53,5 a 59,5 GHz), com perda de retorno maior que 10 dB (de 51 a 63 GHz) e um pequeno deslocamento em relação à banda especificada. Os resultados de medição de algumas amostras demonstraram que a tecnologia HTCC, para integração do sistema, é viável tanto em termos de desempenho, quanto nos aspectos industrial e comercial, mesmo antes da análise da montagem e desempenho do MMIC HPA e do sistema
Abstract: This Master's degree work, entitled System-in-Package (SiP) Integration of 60 GHz Transceiver for Wireless High Definition Multimedia Interface Application, was executed at STMicroelectronics Company (France), Minatec site in the department of Research and Technological Development/Central CAD and Solutions Department, under the guidance of PhD. Andreia Cathelin. The objective was to research and propose a SiP integration for industrial production. The Multi-Chip Module with ceramic materials (MCM-C) of High Temperature Cofired Ceramic technology (HTCC) was developed. Components and devices of different technologies - an RF 65 nm CMOS Integrated Circuit (IC), a commercial Gallium Arsenide (GaAs) monolithic microwave IC (MMIC), and IPD (Integrated Passive Device) antennas with glass substrate - were integrated into the same module. Further design techniques were developed complying with techniques for industrial assembly and the design rules of Kyocera, the company which provides HTCC technology and module manufacturing. The complete system integration was designed with electronic design automation (EDA) software tools with electrical and electromagnetic simulation resulting in a 13 x 8 mm2 area and 1.12 mm thickness module including its components. The 60 GHz and the base band transmission lines presented an insertion loss of 1.0 dB/mm and 0.6 dB respectively. The IPD antenna integrated in the module presented a 6 dBi minimum gain (53.5 to 59.5 GHz band) with return loss above 10 dB (51 to 63 GHz band) and a small shift of the frequency band. The measurement results of some assembled samples showed that HTCC technology is viable in terms of performance and industrial production for the 60 GHz application, even before the analysis of MMIC HPA and the system evaluation
Mestrado
Eletrônica, Microeletrônica e Optoeletrônica
Mestre em Engenharia Elétrica

This thesis reports the development and analysis of high performance CMOS readout electronics for increasing the performance of MEMS gyroscopes developed at Middle East Technical University (METU). These readout electronics are based on unity gain buffers implemented with source followers. High impedance node biasing problem present in capacitive interfaces is solved with the implementation of a transistor operating in the subthreshold region. A generalized fully differential gyroscope model with force feedback electrodes has been developed in order to simulate the capacitive interfaces with the model of the gyroscope. This model is simplified for the single ended gyroscopes fabricated at METU, and simulations of resonance characteristics are done. Three gyroscope interfaces are designed by considering the problems faced in previous interface architectures. The first design is implemented using a single ended source follower biased with a subthreshold transistor. From the simulations, it is observed that biasing impedances up to several gigaohms can be achieved. The second design is the fully differential version of the first design with the addition of a self biasing scheme. In another interface, the second design is modified with an instrumentation amplifier which is used for fully differential to single ended conversion. All of these interfaces are fabricated in a standard 0.6 µ
m CMOS process. Fabricated interfaces are characterized by measuring their ac responses, noise response and transient characteristics for a sinusoidal input. It is observed that, biasing impedances up to 60 gigaohms can be obtained with subthreshold transistors. Self biasing architecture eliminates the need for biasing the source of the subthreshold transistor to set the output dc point to 0 V. Single ended SOG gyroscopes are characterized with the single ended capacitive interfaces, and a 45 dB gain improvement is observed with the addition of capacitive interface to the drive mode. Minimum resolvable capacitance change and displacement that can be measured are found to be 58.31 zF and 38.87 Fermi, respectively. The scale factor of the gyroscope is found to be 1.97 mV/(°
/sec) with a nonlinearity of only 0.001% in ±
100 °
/sec measurement range. The bias instability and angle random walk of the gyroscope are determined using Allan variance method as 2.158 °
/&
#8730
hr and 124.7 °
/hr, respectively.

SiGe BiCMOS technology has many advantageous properties that, when leveraged, enable circuit design for extreme environments. This work will focus on designs targeted for space system avioinics platforms under the NASA ETDP program. The program specifications include operation under temperatures ranging from -180 C to +125 C and with radiation tolerance up to total ionizing dose of 100 krad with built-in single-event latch-up tolerance. To the author's knowledge, this work presents the first design and measurement of a wide temperature range enabled, radiation tolerant as built, RS-485 wireline transceiver in SiGe BiCMOS technology. This work also includes design and testing of a charge amplification channel front-end intended to act as the interface between a piezoelectric sensor and an ADC. An additional feature is the design and testing of a 50 Ohm output buffer utilized for testing of components in a lab setting.

This thesis focuses on the use of surface modifiers as tools for probing and/or controlling interfaces. Surface modification of transparent conducting oxides (TCOs) with organic and organometallic modifiers can be used as a tool for mediating interfacial energetics as well as probing the kinetics of charge-transfer at the metal oxide/organic interface. The synthetic tunability of these modifiers allows us to design molecules based on various parameters, which include the nature of the binding, spacer, and terminal groups. Based on this framework, several modifiers were synthesized and used to investigate surface energy tuning as well as charge injection kinetics as a function of molecular structure. More specifically, we use XPS/UPS to examine the evolution of the chemical structure and frontier orbital levels of the TCO/organic interface as a function of the chosen surface modifier. In addition, we investigate the impact that various molecular binding groups have on mediating the kinetics of charge-transfer. In the last section of this body of work we examine the development of dielectric nanocomposite films for capacitor applications. More specifically, we examine the use of phosphonic acid modifiers to functionalize barium titanate nanoparticles in order to provide miscibility with a suitable polymer host. The effect of various modifiers on the dielectric properties not nanocomposite thin films was examined.

This work focuses on the interface circuitry design for MEMS resonator-based vacuum sensors. Two new measurement system topologies are proposed. The required specifications and the design of the comprising blocks for each topology are studied in detail. Next, the correct functionality and performance specifications of both architectures – designed in an IBM 0.13 μm CMOS technology – are presented through a combination of post-layout simulations and measurement results. Furthermore, the advantages and disadvantages of each design are examined in detail, followed by a comparison to similar commercial systems currently available on the market.Finally, setting the ultimate goal of building a low-power, monolithic, integrated MEMS-based temperature-compensated vacuum measurement system, areas with potential for future improvement, and expansion are discussed.
Ce travail présente la conception de circuits d'interface, pour la mesure de pression sous vide à l'aide de résonateurs MEMS. Deux nouvelles structures de systèmes de mesure sont proposées. Les spécifications requises, ainsi que la conception des blocs composants pour chaque structure, sont étudiées en détail. Par la suite, l'opération adéquate et les spécifications de performance pour les deux architectures - conçues par la technologie CMOS de IBM à 0.13 μm - sont présentées par une combinaison de simulations post-layout et de résultats mesurés. De plus, les avantages et inconvénients de chaque structure sont évalués en détail, suivis d'une comparaison avec des systèmes commerciaux similaires présentement disponibles sur le marché. Finalement, pour s'approcher du but ultime de construire le meilleur système intégré et monolithique de mesure de pression sous vide, à faible consommation de puissance et avec compensation pour les variations thermiques, les possibilités d'améliorations futures et d'extension sont discutées.

This thesis presents the development of high resolution, wide dynamic range sigma-delta type readout circuits for capacitive MEMS accelerometers. Designed readout circuit employs fully differential closed loop structure with digital output, achieving high oversampling ratio and high resolution. The simulations of the readout circuit together with the accelerometer sensor are performed using the models constructed in Cadence and Matlab Simulink environments. The simulations verified the stability and proper operation of the accelerometer system. The sigma-delta readout circuit is implemented using XFab 0.6 µ
m CMOS process. Readout circuit is combined with Silicon-On-Glass (SOG) and Dissolved Wafer Process (DWP) accelerometers. Both open loop and closed loop tests of the accelerometer system are performed. Open loop test results showed high sensitivity up to 8.1 V/g and low noise level of 4.8 µ
g/&
#61654
Hz. Closed loop circuit is implemented on a PCB together with the external filtering and decimation electronics, providing 16-bit digital output at 800 Hz sampling rate. High acceleration tests showed ±
18.5 g of linear acceleration range with high linearity, using DWP accelerometers. The noise tests in closed loop mode are performed using Allan variance technique, by acquiring the digital data. Allan variance tests provided 86 µ
g/&
#61654
Hz of noise level and 74 µ
g of bias drift. Temperature sensitivity tests of the readout circuit in closed loop mode is also performed, which resulted in 44 mg/º
C of temperature dependency. Two different types of new adaptive sigma-delta readout circuits are designed in order to improve the resolution of the systems by higher frequency operation. The two circuits both change the acceleration range of operation of the system, according to the level of acceleration. One of the adaptive circuits uses variation of feedback time, while the other circuit uses multi-bit feedback method. The simulation results showed micro-g level noise in closed loop mode without the addition of the mechanical noise of the sensor.

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems can be employed that interpret the natural electric signals produced by the human body as command inputs. One of these novel sensor systems is the myoelectric detection circuit, which can measure electromyographic (EMG) signals produced by contracting muscles through specialized electrodes, and convert the signals into a usable form through an analog circuit. With the goal of making a general-purpose myoelectric detection circuit platform for computer interface applications, several electrical circuit designs were iterated using OrCAD software, manufactured using PCB fabrication techniques, and tested with electrical measurement equipment and in a computer simulation. The analog circuit design culminated in a 1.35” x 0.8” manufactured analog myoelectric detection circuit unit that successfully converts a measured EMG input signal from surface skin electrodes to a clean and usable 0-5 V DC output that seamlessly interfaces with an Arduino Leonardo microcontroller for further signal processing and logic operations. Multiple input channels were combined with a microcontroller to create an EMG interface device that was used to interface with a PC, where simulated mouse cursor movement was controlled through the voluntary EMG signals provided by a user. Functional testing of the interface device was performed, which showed a long battery life of 44.6 hours, and effectiveness in using a PC to type with an on-screen keyboard.

ABSTRACT DESIGN AND IMPLEMENTATION OF A MICROPROCESSOR BASED DATA COLLECTION AND INTERPRATATION SYSTEM WITH ONBOARD GRAPHICAL INTERFACE Gö
ksü
gü
r, Gö
khan M.S., Department of Electric and Electronics Engineering Supervisor : Prof. Dr. Hasan Cengiz Gü
ran December 2004, 103 pages This thesis reports the design and implementation of a microprocessor based interface unit of a navigation system. The interface unit is composed of a TFT display screen for graphical interface, a Controller Circuit for system control, a keypad interface for external data entrance to the system and a power interface circuit to provide interface between the battery of the navigation system and the Controller Circuit. This thesis reports high speed design of the Controller Circuit and generation of system functions. Main functions of the interface unit are communicating with navigation computer and providing a graphical interface to the driver of the vehicle containing the navigation system. Communication and graphical data preparation functions are implemented through the use of a microprocessor. Driver function of TFT display is implemented through the use of a Field Programmable Gate Array, which is programmed using the Very High Speed IC Description Language (VHDL). Keywords: Navigation System, Interface Unit, Controller Circuit, Image Generation

This thesis reports the development of advanced readout and control electronics for MEMS gyroscopes developed at METU. These gyroscope electronics are separated into three main groups: high sensitive interface circuits, drive mode amplitude controlled self oscillation loops, and sense mode phase sensitive amplitude demodulators. The proposed circuits are first implemented with discrete components, and then integrated on CMOS chips. A self oscillation loop enabling constant amplitude drive mode vibrations independent of sensor parameters and ambient conditions is developed. A fully functional angular rate system, which is constructed by employing this advanced control electronics together with the transresistance amplifier type interfaces and sense mode electronics, is implemented on a dedicated PCB having 5.4x2.4 cm2 area. This system demonstrates an impressive performance far better than the best performance achieved by any angular rate system developed at METU. Bias instability and angle random walk values are measured as 14.3 º
/hr and 0.126 º
/&
#8730
hr, respectively. The scale factor of the system is found as 22.2 mV/(º
/sec) with a nonlinearity of 0.01%, and a zero rate output of 0.1 º
/sec, in ±
50 º
/sec measurement range. CMOS unity gain buffer (UGB) and transimpedance amplifier (TIA) type resistive and capacitive interfaces are characterized through AC, transient, and noise tests. It is observed that on chip biasing mechanisms properly DC-bias the high impedance nodes to 0 V potential. UGB type capacitive interfaces demonstrate superior performance than TIA counterparts due to stability problems associated with TIA interfaces. CMOS differential drive mode control and sense mode demodulation electronics give promising results for the future performance tests.

This thesis reports the development of various high performance readout and control electronics for implementing angular rate sensing systems using MEMS gyroscopes developed at METU. First, three systems with open loop sensing mechanisms are implemented, where each system has a different drive-mode automatic gain controlled (AGC) self-oscillation loop approach, including (i) square wave driving signal with DC off-set named as OLS_SquD, (ii) sinusoidal driving signal with DC off-set named as OLS_SineD, and iii) off-resonance driving signal named as OLS_OffD. A forth system is also constructed with a closed loop sensing mechanism where the drive mode automatic gain controlled (AGC) self-oscillation loop approach with square wave driving signal with DC off-set named as CLS_SquD. Sense and drive mode electronics employ transimpedance and transresistance amplifiers as readout electronics, respectively. Each of the systems is implemented with commercial discrete components on a dedicated PCB. Then, the angular rate sensing systems are tested with SOG (Silicon-on-Glass) gyroscopes that are adjusted to have two different mechanical bandwidths, more specially 100 Hz and 30 Hz. Test results of all of these cases verify the high performance of the systems. For the 100 Hz bandwidth, the OLS_SquD system shows a bias instability of 4.67 &
#730
/hr, an angle random walk (ARW) 0.080 &
#730
/&
#8730
hr, and a scale factor of 22.6 mV/(&
#730
/sec). For the 30 Hz bandwidth, the OLS_SquD system shows a bias instability of 5.12 &
#730
/hr, an ARW better than 0.017 &
#730
/&
#8730
hr, and a scale factor of 49.8 mV/(&
#730
/sec). For the 100 Hz bandwidth, the OLS_SineD system shows a bias instability of 6.92 &
#730
/hr, an ARW of 0.049 &
#730
/&
#8730
hr, and a scale factor of 17.97 mV/(&
#730
/sec). For the 30 Hz bandwidth, the OLS_SineD system shows a bias instability of 4.51 &
#730
/hr, an ARW of 0.030 &
#730
/&
#8730
hr, and a scale factor of 43.24 mV/(&
#730
/sec). For the 100 Hz bandwidth, the OLS_OffD system shows a bias instability of 8.43 &
#730
/hr, an ARW of 0.086 &
#730
/&
#8730
hr, and a scale factor of 20.97 mV/(&
#730
/sec). For the 30 Hz bandwidth, the OLS_OffD system shows a bias instability of 5.72 &
#730
/hr, an ARW of 0.046 &
#730
/&
#8730
hr, and a scale factor of 47.26 mV/(&
#730
/sec). For the 100 Hz bandwidth, the CLS_SquD system shows a bias instability of 6.32 &
#730
/hr, an ARW of 0.055 &
#730
/&
#8730
hr, and a scale factor of 1.79 mV/(&
#730
/sec). For the 30 Hz bandwidth, the CLS_SquD system shows a bias instability of 5.42 &
#730
/hr, an ARW of 0.057 &
#730
/&
#8730
hr, and a scale factor of 1.98 mV/(&
#730
/sec). For the 100 Hz bandwidth, the R2 nonlinearities of the measured scale factors of all systems are between 0.0001% and 0.0003% in the ±
100 &
#730
/sec measurement range, while for the 30 Hz bandwidth the R2 nonlinearities are between 0.0002% and 0.0062% in the ±
80&
#730
/sec measurement range. These performance results are the best results obtained at METU, satisfying the tactical-grade performances, and the measured bias instabilities and ARWs are comparable to the best results in the literature for a silicon micromachined vibratory gyroscope.

Isotropically conductive adhesives (ICAs) are promising as a lead-free interconnect material; However, ICAs have a higher resistivity compared to tin/lead solder. The higher resistivity of ICAs results from the large contact resistance between conductive fillers. Several novel approaches to engineer the interface between electrically conductive fillers were studied to develop highly conductive ICAs. Shown in this dissertation are three methodologies to reduce contact resistance: low temperature sintering, fast sintering and in-situ reduction. Furthermore, two approaches, surface modification and in-situ protection, were developed to prevent oxidation and corrosion of silver-coated copper flakes to produce low cost ICAs. The findings and insights in this dissertation significantly contribute to (1) understanding of filler-filler, filler-polymer and structure-property relationships of ICAs; (2) the structural design and formulation of high performance ICAs; and (3) the wider use of ICAs in emerging applications such as printed electronics and solar cells.

Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xvi, 136 p.; also includes graphics (some col.). Includes bibliographical references (p. 125-136). Available online via OhioLINK's ETD Center

This thesis reports the development of high-performance symmetric and decoupled micromachined gyroscopes for tactical-grade inertial measurement applications. The symmetric structure allows easy matching of the resonance frequencies of the drive and sense modes of the gyroscopes for achieving high angular rate sensitivity
while the decoupled drive and sense modes minimizes mechanical cross-coupling for low-noise and stable operation. Three different and new symmetric and decoupled gyroscope structures with unique features are presented. These structures are fabricated in four different micromachining processes: nickel electroforming (NE), dissolved-wafer silicon micromachining (DWSM), silicon-on-insulator (SOI) micromachining, and silicon-on-glass (SOG) micromachining. The fabricated gyroscopes have capacitive gaps from 1.5µ
m to 5.5µ
m and structural layer thicknesses from 12µ
m to 100µ
m, yielding aspect ratios up to 20 depending on the fabrication process. The size of fabricated gyroscope chips varies from 1x1mm2 up to 4.2x4.6mm2. Fabricated gyroscopes are hybrid-connected to a designed capacitive interface circuit, fabricated in a standard 0.6µ
m CMOS process. They have resonance frequencies as small as 2kHz and as large as 40kHz
sense-mode resonance frequencies can be electrostatically tuned to the drive-mode frequency by DC voltages less than 16V. The quality factors reach to 500 at atmospheric pressure and exceed 10,000 for the silicon gyroscopes at vacuum. The parasitic capacitance of the gyroscopes on glass substrates is measured to be as small as 120fF. The gyroscope and interface assemblies are then combined with electronic control and feedback circuits constructed with off-the-shelf IC components to perform angular rate measurements. Measured angular rate sensitivities are in the range from 12µ
V/(deg/sec) to 180µ
V/(deg/sec), at atmospheric pressure. The SOI gyroscope demonstrates the best performance at atmospheric pressure, with noise equivalent rate (NER) of 0.025(deg/sec)/Hz1/2, whereas the remaining gyroscopes has an NER better than 0.1(deg/sec)/Hz1/2, limited by either the small sensor size or by small quality factors. Gyroscopes have scale-factor nonlinearities better than 1.1% with the best value of 0.06%, and their bias drifts are dominated by the phase errors in the demodulation electronics and are over 1deg/sec. The characterization of the SOI and SOG gyroscopes at below 50mTorr vacuum ambient yield angular rate sensitivities as high as 1.6mV/(deg/sec) and 0.9mV/(deg/sec), respectively. The NER values of these gyroscopes at vacuum are smaller than 50(deg/hr)/Hz1/2 and 36(deg/hr)/Hz1/2, respectively, being close to the tactical-grade application limits. Gyroscope structures are expected to provide a performance better than 10 deg/hr in a practical measurement bandwidth such as 50Hz, provided that capacitive gaps are minimized while preserving the aspect ratio, and the demodulation electronics are improved.

Le tungstene depose par le procede l. P. C. V. D. Semble etre un materiau susceptible d'apporter des solutions aux nombreux problemes d'interconnexion poses par la diminution constante de la taille des circuits integres. Ce memoire presente le travail portant sur les themes suivants: 1) optimisation des conditions de depot de tungstene et caracterisation, 2) caracterisation de l'interface tungstene-silicium, 3) stabilite thermique de la structure w/si et 4) faisabilite de l'utilisation du tungstene comme une barriere de diffusion dans la structure al/w/si

A model is presented which incorporates the advantages of a mixed mode simulation to characterize transmission line behavior in multiple coupled Transmission line systems. The model is intended for use by digital circuit designers who wish to be able to obtain accurate transmission line behavior for complex digital systems for which continuous time simulation tools such as SPICE would time prohibitive. The model uses a transverse electromagnetic wave approximation to obtain solutions to the basic transmission line equations. A modal analysis technique is used to solve for the attenuation and propagation constants for the transmission lines. Modal analysis done in the frequency domain after a Fast Fourier Transform of the time-domain input signals. Boundary conditions are obtained from the Thevinized transmission line input equivalent circuit and the transmission line output load impedance. The model uses a unique solution queue system that allows n-line coupled transmission lines to be solved without resorting to large order matrix methods or the need to diagonals larger matrices using linear transformations. This solution queue system is based on the method of solution superposition. As a result, the CPU time required for the model is primarily a function of the number of transitions and not the number of lines modeled. Incorporation of the model into event driven circuit simulators such as Network C is discussed. It will be shown that the solution queue methods used in this model make it ideally suited for incorporation into a event-driven simulation network. The model presented in this thesis can be scaled to incorporate direct electromagnetic coupling between first, second, or third lines adjacent to the line transitioning. It is shown that modeling strictly adjacent line coupling is adequate for typical digital technologies. It is shown that the model accurately reproduces the transmission line behavior of systems modeled by previous authors. Example transitions on a 8-line system are reviewed. Finally, future model improvements are discussed.

Adding Power Electronic Interfaced Devices (PEID) generation to grids is an increasing trend because of the concurrent development of better power electronic converters and a greater interest in a better utilisation of energy resources. Small and dispersed energy sources that would previously not be worth introducing into the grid is becoming more and more viable and other potential benefits such as better control of voltage levels and smoothing out load changes also spur this development. But while there are great potential benefits of the controllability of these devices there are also risks when existing protection systems are made for the linear behaviour of traditional synchronous generators. This thesis describes the peculiarities of the short circuit behaviour of PEID generators and how this affects the short circuit energy levels in terms of short circuit current, I2t and incident arc energy. Using simulation, it is shown that in the case of the specific mine grid studied, the incident arc energy increases substantially and that this need to be considered when evaluating installation of PEID generation.
Användningen av nätansluten omformardriven generering ökar alltmer i takt med att bättre omformare utvecklas och intresset för ett effektivare nyttjande av energiresurser ökar. Små och utspridda energiresurser som tidigare inte var värda att ta vara på tillgängliggörs alltmer, och fördelar som bättre spänningsreglering och lastutjämning driver på utvecklingen. Men med de fördelar som kommer av omformarnas reglerbarhet så kommer också risker beroende av deras olinjäritet, eftersom existerande skyddssystem är anpassade till det linjära beteendet hos traditionella synkrongeneratorer. Den här avhandlingen behandlar säregenheterna i kortslutningsbeteendet hos effektelektroniska omformare och hur det påverkar kortslutningsenergin i bemärkelsen I2t, händelseenergin vid ljusbågar samt kortslutningsströmmen. Via dynamisk simulering så visas att händelseenergin i vissa fall kan öka avsevärt och att detta behöver övervägas vid installation av omformardriven generering.

[EN] Different electronic interfaces have been proposed to measure major parameters for the characterization of quartz crystal microbalance (QCM) during the last two decades. The measurement of the adequate parameters of the sensor for a specific application is very important, since an error in this measure can lead to an error in the interpretation of the results. The requirements of the system of characterization depend on the application. In this thesis we propose two characterization systems for two types of applications that involve the majority of sensor applications: 1) Characterization of materials under variable damping conditions and 2) Detection of substances with high measurement resolution. The proposed systems seek to solve the problems detected in the systems currently in use. For applications in which the sensor damping varies during the experiment, we propose a system based on a new configuration of the technique of automatic capacitance compensation (ACC). This new configuration provides the measure of the series resonance frequency, the motional resistance and the parallel capacitance of the sensor. Moreover, it allows an easy calibration of the system that improves the precision in the measurement. We show the experimental results for 9 and 10 MHz crystals in fluid media, with different capacitances in parallel, showing the effectiveness in the capacitance compensation. The system presents some deviation in frequency with respect to the series resonance frequency, as measured with an impedance analyser. These deviations are due to the non-ideal, specific behaviour of some of the components of the circuit. A new circuit is proposed as a possible solution to this problem. For high-resolution applications we propose an integrated platform to characterize high-frequency acoustic sensors. The proposed system is based on a new concept in which the sensor is interrogated by means of a very stable, low-noise external source at a constant frequency, while the changes provoked by the charge in the phase of the sensor are monitored. The use of high-frequency sensors enhances the sensitivity of the measure, whereas the design characterization system reduces the noise in the measurement. The result is an improvement in the limit of detection (LOD). This way, we achieve one of the challenges in the acoustic high-frequency devices. The validation of the platform is performed by means of an immunosensor based in high fundamental frequency QCM crystals (HFF-QCM) for the detection of two pesticides: carbaryl and thiabendazole. The results obtained for carbaryl are compared to the results obtained by another high-frequency acoustic technology based in Love sensors, with the optical technique based in surface plasmonic resonance and with the gold standard technique Enzyme Linked Immunoassay (ELISA). The LOD obtained with the acoustic sensors HFF-QCM and Love is similar to the one obtained with ELISA and improves by one order of magnitude the LOD obtained with SPR. The conceptual ease of the proposed system, its low cost and the possibility of miniaturization of the quartz resonator, allows the characterization of multiple sensors integrated in an array configuration, which will allow in the future to achieve the challenge of multianalyte detection for applications of High-Throughput Screening (HTS).
[ES] Durante las dos últimas décadas se han propuesto diferentes interfaces electrónicos para medir los parámetros más importantes de caracterización de los cristales de microbalanza de cuarzo (QCM). La medida de los parámetros adecuados del sensor para una aplicación específica es muy importante, ya que un error en la medida de dichos parámetros puede resultar en un error en la interpretación de los resultados. Los requerimientos del sistema de caracterización dependen de la aplicación. En esta tesis se proponen dos sistemas de caracterización para dos ámbitos de aplicación que comprenden la mayoría de las aplicaciones con sensores QCM: 1) Caracterización de materiales bajo condiciones de amortiguamiento variable y 2) detección de sustancias con alta resolución de medida. Los sistemas propuestos tratan de resolver la problemática detectada en los ya existentes. Para aplicaciones en las que el amortiguamiento del sensor varía durante el experimento, se propone un sistema basado en una nueva configuración de la técnica de compensación automática de capacidad (ACC). La nueva configuración proporciona la medida de la frecuencia de resonancia serie, la resistencia dinámica y la capacidad paralelo del sensor. Además, permite una fácil calibración del sistema que mejora la precisión en la medida. Se presentan resultados experimentales para cristales de 9 y 10MHz en medios fluidos, con diferentes capacidades en paralelo, demostrando la efectividad de la compensación de capacidad. El sistema presenta alguna desviación en frecuencia con respecto a la frecuencia resonancia serie, medida con un analizador de impedancias. Estas desviaciones son explicadas convenientemente, debidas al comportamiento no ideal específico de algunoscomponentes del circuito. Una nueva propuesta de circuito se presenta como posible solución a este problema. Para aplicaciones de alta resolución se propone una plataforma integrada para caracterizar sensores acústicos de alta frecuencia. El sistema propuesto se basa en un nuevo concepto en el que el sensor es interrogado, mediante una fuente externa muy estable y de muy bajo ruido, a una frecuencia constante mientras se monitorizan los cambios producidos por la carga en la fase del sensor. El uso de sensores de alta frecuencia aumenta la sensibilidad de la medida, por otro lado, el sistema de caracterización diseñado reduce el ruido en la misma. El resultado es una mejora del límite de detección (LOD). Se consigue con ello uno de los retos pendientes en los dispositivos acústicos de alta frecuencia. La validación de la plataforma desarrollada se realiza con una aplicación de un inmunosensor basado en cristales QCM de alta frecuencia fundamental (HFF-QCM) para la detección de dos pesticidas: carbaryl y tiabendazol. Los resultados obtenidos para el Carbaryl se comparan con los obtenidos con otra tecnología acústica de alta frecuencia basada en sensores Love, con la técnica óptica basada resonancia superficial de plasmones (SPR) y con la técnica de referencia Enzyme Linked Immuno Assay (ELISA). El LOD obtenido con los sensores acústicos HFFQCM y Love es similar al obtenido con las técnicas ELISA y mejora en un orden de magnitud al obtenido con SPR. La sencillez conceptual del sistema propuesto junto con su bajo coste, así como la capacidad de miniaturización del resonador de cuarzo hace posible la caracterización de múltiples sensores integrados en una configuración en array, esto permitirá en un futuro alcanzar el reto de la detección multianalito para aplicaciones High-Throughput Screening (HTS).
[CAT] Durant les dues últimes dècades s'han proposat diferents interfases electrònics per a mesurar els paràmetres més importants de caracterització dels cristalls de microbalança de quars (QCM). La mesura dels paràmetres adequats del sensor per a una aplicació específica és molt important, perquè un error en la interpretació dels resultats pot resultar en un error en la interpretació dels resultats. Els requeriments del sistema de caracterització depenen de l'aplicació. En aquesta tesi, es proposen dos sistemes de caracterització per a dos àmbits d'aplicació que comprenen la majoria de les aplicacions amb sensors QCM: 1) Caracterització de materials sota condicions d'amortiment variable i 2) detecció de substàncies amb alta resolució de mesura. Els sistemes proposats tracten de resoldre la problemàtica detectada en els ja existents. Per a aplicacions en les quals l'amortiment del sensor varia durant l'experiment, es proposa un sistema basat en una nova configuració de la tècnica de compensació automàtica de capacitat (ACC). La nova configuració proporciona la mesura de la freqüència de ressonància sèrie, la resistència dinàmica i la capacitat paral¿lel del sensor. A més, permet un calibratge fàcil del sistema que millora la precisió de la mesura. Es presenten els resultats experimentals per a cristalls de 9 i 10 MHz en mitjans fluids, amb diferents capacitats en paral¿lel, demostrant l'efectivitat de la compensació de capacitat. El sistema presenta alguna desviació en freqüència respecte a la freqüència ressonància sèrie, mesurada amb un analitzador d'impedàncies. Aquestes desviacions són explicades convenientment, degudes al comportament no ideal específic d'alguns components del circuit. Una nova proposta de circuit es presenta com a possible solució a aquest problema. Per a aplicacions d'alta resolució es proposa una plataforma integrada per a caracteritzar sensors acústics d'alta freqüència. El sistema proposat es basa en un nou concepte en el qual el sensor és interrogat mitjançant una font externa molt estable i de molt baix soroll, a una freqüència constant mentre es monitoritzen els canvis produïts per la càrrega en la fase del sensor. L'ús de sensors d'alta freqüència augmenta la sensibilitat de la mesura, per altra banda, el sistema de caracterització dissenyat redueix el soroll en la mateixa. El resultat és una millora en el límit de detecció (LOD). S'aconsegueix amb això un dels reptes pendents en els dispositius acústics d'alta freqüència. La validació de la plataforma desenvolupada es realitza amb una aplicació d'un immunosensor basat en cristalls QCM d'alta freqüència fonamental (HFF-QCM) per a la detecció de dos pesticides: carbaryl i tiabendazol. Els resultats obtinguts per al carbaryl es comparen amb els obtinguts amb altra tecnologia acústica d'alta freqüència basada en sensors Love, amb la tècnica òptica basada en ressonància superficial de plasmons (SPR) i amb la tècnica de referència Enzyme Linked Immuno Assay (ELISA). El LOD obtingut amb els sensors acústics HFF-QCM i Love és similar al obtingut amb les tècniques ELISA i millora en un ordre de magnitud el obtingut amb SPR. La senzillesa conceptual del sistema proposat junt amb el seu baix cost, així com la capacitat de miniaturització del ressonador de quars fa possible la caracterització de múltiples sensors integrats en una configuració en array, el que permetrà en un futur assolir el repte de la detecció multianalit per a aplicacions High-Throughput Screening (HTS).
García Narbón, JV. (2016). Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63249
TESIS

Cette thèse concerne la récupération d'énergie vibratoire dans le but de proposer une alternative aux batteries conventionnelles pour l’alimentation de systèmes autonomes sans fil. Ceci permettrait d’améliorer leur compacité (moins d’énergie stockée), leur tenue dans des environnements sévères (forte température) et de réduire leur besoin d'entretien. Cette étude se concentre plus particulièrement sur les générateurs oscillants bistables, intéressants pour leur grande plage de fréquences utile comparée à celle offerte par les générateurs linéaires (limitée à la zone de résonance). Cette thèse se divise en quatre grandes parties. La première présente la construction du modèle mathématique permettant de prédire les différents comportements du générateur bistable (ces derniers pouvant coexister sur certaines plages de fréquences) incluant l'étude de la stabilité aux petites perturbations. Ce modèle met en évidence des comportements du générateur encore peu exploités pour la récupération d'énergie : les comportements sous-harmoniques dont la plage de fréquences permet d'agrandir la bande passante globale du générateur. Afin d’améliorer la précision du modèle, celui-ci est ensuite complété dans la deuxième partie par un critère semi-analytique : le critère de robustesse de stabilité qui caractérise la sensibilité du générateur aux perturbations extérieures (plus un comportement est robuste plus il sera facile à maintenir dans le temps). Le modèle ainsi obtenu ainsi que le système expérimentale montrent une grande plage de fréquences sur laquelle coexistent des comportements intéressants pour la récupération d’énergie (les orbites hautes) et des comportements non désirables (les orbites basses). La troisième partie de cette thèse présente donc différentes stratégies permettant de sauter des orbites basses vers les orbites hautes en jouant directement sur les paramètres du générateur. Enfin, la quatrième et dernière partie s’attarde sur l’influence du circuit d'interface AC-DC entre le générateur bistable et la charge en vue de son intégration future
This thesis concerns vibratory energy harvesting in order to propose an alternative to conventional batteries for the power supply of autonomous wireless systems. This would improve their compactness (less stored energy), their resistance to harsh environments (high temperature) and reduce their need for maintenance. This study focuses in particular on bistable oscillating generators, which are interesting for their large useful frequency range compared to that offered by linear generators (limited to the resonance zone). This thesis is divided into four main parts. The first presents the construction of the mathematical model to predict the different behaviors of the bistable generator (these behaviors can coexist over certain frequency ranges) including the study of stability to small disturbances. This model highlights original behaviors for energy recovery: subharmonic behaviors whose frequency range allows increasing the overall generator bandwidth. In order to improve the accuracy of the model, a semi-analytical criterion is then added: the stability robustness criterion which characterizes the sensitivity of the different behaviors to external disturbances (the more robust a behavior, the easier to maintain over time). The model obtained and the experimental prototype show a wide frequency range on which the interesting behaviors (high orbits) and the undesirable behaviors (low orbits) coexist. The third part of this thesis therefore presents different strategies for jumping from low to high orbits by playing directly on the generator parameters. Finally, the fourth and last part focuses on the influence of the AC-DC interface circuit between the bistable generator and the load for future integration

This thesis presents a mathematical model of the nanoporous anode within a dyesensitised solar cell (DSC). The main purpose of this work is to investigate interfacial charge transfer and charge transport within the porous anode of the DSC under both illuminated and non-illuminated conditions. Within the porous anode we consider many of the charge transfer reactions associated with the electrolyte species, adsorbed dye molecules and semiconductor electrons at the semiconductor-dye- electrolyte interface. Each reaction at this interface is modelled explicitly via an electrochemical equation, resulting in an interfacial model that consists of a coupled system of non-linear algebraic equations. We develop a general model framework for charge transfer at the semiconductor-dye-electrolyte interface and simplify this framework to produce a model based on the available interfacial kinetic data. We account for the charge transport mechanisms within the porous semiconductor and the electrolyte filled pores that constitute the anode of the DSC, through a one- dimensional model developed under steady-state conditions. The governing transport equations account for the diffusion and migration of charge species within the porous anode. The transport model consists of a coupled system of non-linear differential equations, and is coupled to the interfacial model via reaction terms within the mass-flux balance equations. An equivalent circuit model is developed to account for those components of the DSC not explicitly included in the mathematical model of the anode. To obtain solutions for our DSC mathematical model we develop code in FORTRAN for the numerical simulation of the governing equations. We additionally employ regular perturbation analysis to obtain analytic approximations to the solutions of the interfacial charge transfer model. These approximations facilitate a reduction in computation time for the coupled mathematical model with no significant loss of accuracy. To obtain predictions of the current generated by the cell we source kinetic and transport parameter values from the literature and from experimental measurements associated with the DSC commissioned for this study. The model solutions we obtain with these values correspond very favourably with experimental data measured from standard DSC configurations consisting of titanium dioxide porous films with iodide/triiodide redox couples within the electrolyte. The mathematical model within this thesis enables thorough investigation of the interfacial reactions and charge transport within the DSC.We investigate the effects of modified cell configurations on the efficiency of the cell by varying associated parameter values in our model. We find, given our model and the DSC configuration investigated, that the efficiency of the DSC is improved with increasing electron diffusion, decreasing internal resistances and with decreasing dark current. We conclude that transport within the electrolyte, as described by the model, appears to have no limiting effect on the current predicted by the model until large positive voltages. Additionally, we observe that the ultrafast injection from the excited dye molecules limits the interfacial reactions that affect the DSC current.

The study of neuronal and neurodegenerative diseases requires the development of new tools and technologies to create functional neuroelectronics allowing both stimulation and recording of cellular electrical activity. In the last decade organic electronics is digging its way in the field of bioelectronics and researchers started to develop neural interfaces based on organic semiconductors. The interest in such technologies arise from the intrinsic properties of organic materials such as low cost, transparency, softness and flexibility, as well the biocompatibility and the suitability in realizing all organic printed systems. In particular, organic field-effect transistor (OFET) -based biosensors integrate the sensing and signal amplification in a single device, paving the way to new implantable neural interfaces for in vivo applications. To master the sensing and amplification properties of the OFET-based sensors, it is mandatory to gain an intimate knowledge of the single transistors (without any analytes or cells) that cannot be limited to basic characterizations or to general models. Moreover, organic transistors are characterized by different working principles and properties as respect to their inorganic counterpart. We performed pulsed and transient characterization on different OFETs (both p-type and n-type) showing that, even though the transistors can switch on and off very fast, the accumulation and/or the depletion of the conductive channel continues for times as long as ten seconds. Such phenomenon must be carefully considered in the realization of a biosensor and in its applications, since the DC operative point of the device can drift during the recording of the cellular signals, thus altering the collected data. We further investigate such phenomenon by performing characterizations at different temperatures and by applying the deep level transient spectroscopy technique. We showed that the slow channel accumulation (and depletion) is due to the semiconductor density-of-states that must be occupied in order to bring the Fermi energy level close to the conduction band. This is a phenomenon that can takes several seconds and we described it by introducing a time-depend mobility. We also proposed a technique to estimate the behavior, in time, of the position of the Fermi energy level as respect to the conduction band. To understand the electrochemical transduction processes between living cell and organic biosensor, we realized two-electrodes structure (STACKs) where a drop of saline solution is put directly in contact with the organic semiconductor. On these devices, we performed electrochemical impedance spectroscopy at different DC polarizations and we developed an equivalent circuit model for the metal-organic semiconductor-solution structures that are typically used as transducers in biosensor devices. Our approach was extending the standard range of the bias voltages applied for devices that operate in water. This particular characterization protocol allowed to distinguish and investigate the different mechanisms that occur at the different layers and interfaces: adsorption of ions in the semiconductor; accumulation and charge exchange of carriers at the semiconductor/electrolyte interface; percolation of the ionic species through the organic semiconductor; ion diffusion across the electrolyte; ion adsorption and charge exchange at the platinum interface. We highlighted the presence of ion percolation through the organic semiconductor layer, which is described in the equivalent circuit model by means of a de Levie impedance. The presence of percolation has been demonstrated by environmental scanning electron microscopy and profilometry analysis. Although percolation is much more evident at high negative bias values, it is still present even at low bias conditions. In addition, we analyze two case studies of devices featuring NaCl (concentration of 0.1M) and MilliQ water as solution, showing that both cases can be considered as a particular case of the general model presented in this manuscript. The very good agreement between the model and the experimental data makes the model a valid tool for studying the transducing mechanisms between organic films and the physiological environment. Hence this model could be a useful tool not only for the characterization and failure analysis of electronic devices, such as water-gated transistors, electrophysiological interfaces, fuel cells, and others electrochemical systems, but also this model might be used in other applications, in which a solution is in intimate contact with another material to determine and quantify, if undesired mechanisms such as percolation and/or redox corrosive processes occur. Lastly, the knowledge gain on OFETs and STACKs were put together to realize electrolyte-gated field effect transistors (EGOFETs). We then developed a model to describes EGOFETs as neural interfaces. We showed that our model can be successfully applied to understand the behaviour of a more general class of devices, including both organic and inorganic transistors. We introduced the reference-less (RL-) EGOFET and we showed that it might be successfully used as a low cost and flexible neural interface for extracellular recording in vivo without the need of a reference electrode, making the implant less invasive and easier to use. The working principle underlying RL-EGOFETs involves self-polarization and back-gate stimulation, which we show experimentally to be feasible by means of a custom low-voltage high-speed acquisition board that was designed to emulate a real-time neuron response. Our results open the door to using and optimizing EGOFETs and RL-EGOFETs for neural interfaces.
Lo studio delle malattie neuronali e neuro-degenerative richiede lo sviluppo di nuovi strumenti e tecnologie per creare dispositivi neuro-elettronici funzionali che consentano sia la stimolazione che la registrazione dell'attività elettrica cellulare. Nell'ultimo decennio l'elettronica organica sta emergendo nel campo della bioelettronica e diversi gruppi di ricerca hanno iniziato a sviluppare interfacce neurali basate su semiconduttori organici. L'interesse per tali tecnologie deriva dalle proprietà intrinseche dei materiali organici quali basso costo, trasparenza, morbidezza e flessibilità, nonché la biocompatibilità e l'idoneità nella realizzazione di sistemi stampati completamente organici. In particolare, i biosensori basati sulla tecnologia a transistor ad effetto campo organico (OFET) integrano il sensing e l'amplificazione del segnale in un singolo dispositivo, aprendo la strada a nuove interfacce neurali impiantabili per applicazioni in vivo. Per padroneggiare le proprietà di rilevamento e amplificazione dei sensori basati su OFET, è obbligatorio acquisire una conoscenza approfondita dei singoli transistor (senza la presenza di analiti e/o cellule) che vadano oltre le caratterizzazioni di base o modelli generali. Inoltre, i transistor organici sono caratterizzati da diversi principi di funzionamento e diverse proprietà rispetto alla loro controparte inorganica. In questo lavoro abbiamo svolto caratterizzazioni impulsate e transienti su diversi OFET (sia di tipo p che di tipo n) mostrando che, anche se i transistor possono accendersi e spegnersi molto velocemente, l'accumulo e/o lo svuotamento del canale conduttivo continua per tempi che possono superare le decine di secondi. Tale fenomeno deve essere attentamente considerato nella realizzazione di un biosensore e nelle sue applicazioni, poiché il punto operativo DC del dispositivo può andare alla deriva durante la registrazione dei segnali cellulari, alterando così i dati raccolti. Questo fenomeno viene ulteriormente approfondito caratterizzano i dispositivi a diverse temperature e per mezzo della tecnica DLTS. Abbiamo dimostrato che il lento accumulo (e svuotamento) del canale è dovuto alla densità di stati del semiconduttore organico che devono poter essere occupati per portare il livello energetico di Fermi vicino alla banda di conduzione. Questo è un fenomeno che può richiedere diversi secondi che possiamo descrivere introducendo una mobilità dipendente dal tempo. Per comprendere i processi di trasduzione elettrochimica tra cellule viventi ed il biosensore organico, abbiamo realizzato una struttura a due elettrodi (STACK) in cui una goccia di soluzione salina viene messa direttamente a contatto con il semiconduttore organico. Su questi dispositivi, abbiamo eseguito la spettroscopia di impedenza elettrochimica a diverse polarizzazioni DC e abbiamo sviluppato un modello circuitale equivalente per le strutture metallo/semiconduttore organico/soluzione che vengono tipicamente utilizzate per la realizzazione di bio-trasduttori. Il nostro approccio prevede di estendere il range standard delle tensioni operative per questo genere di dispositivi. Ciò ha permesso di investigare e distinguere i diversi fenomeni che si verificano nei diversi strati e interfacce: adsorbimento di ioni nel semiconduttore; accumulo e scambio di cariche di portanti all'interfaccia semiconduttore/elettrolita; percolazione delle specie ioniche attraverso il semiconduttore organico; diffusione di ioni attraverso l'elettrolita; adsorbimento di ioni e scambio di carica all'interfaccia col metallo. Abbiamo evidenziato la presenza di percolazione ionica attraverso lo strato di semiconduttore organico, che è descritto nel modello circuitale per mezzo di un'impedenza di de Levie. La presenza di percolazione è stata dimostrata mediante microscopia elettronica a scansione ambientale e analisi profilometrica. Sebbene la percolazione sia molto più evidente a valori di bias negativi elevati, risulta presente anche a basse condizioni di bias. L'ottimo accordo tra il modello e i dati sperimentali rende il modello un valido strumento per studiare i meccanismi di trasduzione tra film organici e l'ambiente fisiologico. Quindi questo modello può essere uno strumento utile non solo per la caratterizzazione e l'analisi dei guasti dei dispositivi elettronici, come water-gated transistor, interfacce elettrofisiologiche, celle a combustibile e altri sistemi elettrochimici, ma anche nel caso in cui una soluzione è in intimo contatto con un altro materiale per determinare e/o quantificare se si verificano meccanismi indesiderati come percolazione e/o processi corrosivi. Infine, il bagaglio di conoscenze ottenuto studiando i dispositivi OFET e STACK è stato messo utillizato per realizzare dispositivi EGOFET. Abbiamo quindi sviluppato un modello per descrivere gli EGOFET come interfacce neurali. Abbiamo dimostrato che il nostro modello può essere applicato con successo per comprendere il comportamento di una classe più generale di dispositivi, compresi i transistor sia organici che inorganici. Abbiamo introdotto l'RL-EGOFET (reference-less EGOFET) e abbiamo dimostrato che questa struttura può essere utilizzata con successo come interfaccia neurale flessibile per il recording extracellulare in vivo senza la necessità di un elettrodo di riferimento, rendendo l'impianto meno invasivo e più facile da usare. I nostri risultati aprono la strada all'utilizzo e all'ottimizzazione di EGOFET e RL-EGOFET come interfacce neurali.

This thesis presents a mathematical model of the nanoporous anode within a dyesensitised solar cell (DSC). The main purpose of this work is to investigate interfacial charge transfer and charge transport within the porous anode of the DSC under both illuminated and non-illuminated conditions. Within the porous anode we consider many of the charge transfer reactions associated with the electrolyte species, adsorbed dye molecules and semiconductor electrons at the semiconductor-dye- electrolyte interface. Each reaction at this interface is modelled explicitly via an electrochemical equation, resulting in an interfacial model that consists of a coupled system of non-linear algebraic equations. We develop a general model framework for charge transfer at the semiconductor-dye-electrolyte interface and simplify this framework to produce a model based on the available interfacial kinetic data. We account for the charge transport mechanisms within the porous semiconductor and the electrolyte filled pores that constitute the anode of the DSC, through a one- dimensional model developed under steady-state conditions. The governing transport equations account for the diffusion and migration of charge species within the porous anode. The transport model consists of a coupled system of non-linear differential equations, and is coupled to the interfacial model via reaction terms within the mass-flux balance equations. An equivalent circuit model is developed to account for those components of the DSC not explicitly included in the mathematical model of the anode. To obtain solutions for our DSC mathematical model we develop code in FORTRAN for the numerical simulation of the governing equations. We additionally employ regular perturbation analysis to obtain analytic approximations to the solutions of the interfacial charge transfer model. These approximations facilitate a reduction in computation time for the coupled mathematical model with no significant loss of accuracy. To obtain predictions of the current generated by the cell we source kinetic and transport parameter values from the literature and from experimental measurements associated with the DSC commissioned for this study. The model solutions we obtain with these values correspond very favourably with experimental data measured from standard DSC configurations consisting of titanium dioxide porous films with iodide/triiodide redox couples within the electrolyte. The mathematical model within this thesis enables thorough investigation of the interfacial reactions and charge transport within the DSC.We investigate the effects of modified cell configurations on the efficiency of the cell by varying associated parameter values in our model. We find, given our model and the DSC configuration investigated, that the efficiency of the DSC is improved with increasing electron diffusion, decreasing internal resistances and with decreasing dark current. We conclude that transport within the electrolyte, as described by the model, appears to have no limiting effect on the current predicted by the model until large positive voltages. Additionally, we observe that the ultrafast injection from the excited dye molecules limits the interfacial reactions that affect the DSC current.

In my thesis I go about principles and methods of security systems, then I go about analysis of avalaible types of security systems (EPS, EZS and CCTV). I have written about their possibile use in design security building. I have described levels of project documentation and its different parts including process service of production a project documentation for security system. I used all knowledges in the end of my thesis, when I designed and integrated security system for a special building.

We focused on a non-cooling room temperature microbolometer infrared imaging array device which includes a sensing layer of p-type a-Si:H component layers doped with boron. Boron incorporation and bonding configuration were investigated for a-Si:H films grown by plasma enhanced chemical deposition (PECVD) at varying substrate temperatures, hydrogen dilution of the silane precursor, and dopant to silane ratio using multiple internal reflection infrared spectroscopy (MIR-IR). This study was then confirmed from collaborators via Raman spectroscopy. MIR-IR analyses reveal an interesting counter-balance relationship between boron-doping and hydrogen-dilution growth parameters in PECVD-grown a-Si:H. Specifically, an increase in the hydrogen dilution ratio (H2/SiH4) or substrate temperature was found to increase organization of the silicon lattice in the amorphous films. It resulted in the decrease of the most stable SiH bonding configuration and thus decrease the organization of the film. The new chemical bonding information of a-Si:H thin film was correlated with the various boron doping mechanisms proposed by theoretical calculations. The study revealed the corrosion morphology progression on aluminum alloy (Al, 0.5% Cu) under acidic chloride solution. This is due to defects and a higher copper content at the grain boundary. Direct galvanic current measurement, linear sweep voltammetry (LSV), and Tafel plots are used to measure corrosion current and potential. Hydrogen gas evolution was also observed (for the first time) in Cu/Al bimetallic interface in areas of active corrosion. Mechanistic insight that leads to effective prevention of aluminum bond pad corrosion is explored and discussed. (Chapter 4) Aluminum bond pad corrosion activity and mechanistic insight at a Cu/Al bimetallic interface typically used in microelectronic packages for automotive applications were investigated by means of optical and scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and electrochemistry. Screening of corrosion variables (temperature, moisture, chloride ion concentration, pH) have been investigated to find their effect on corrosion rate and to better understand the Al/Cu bimetallic corrosion mechanism. The study revealed the corrosion morphology progression on aluminum alloy (Al, 0.5% Cu) under acidic chloride solution. The corrosion starts as surface roughening which evolves into a dendrite structure and later continues to grow into a mud-crack type corrosion. SEM showed the early stage of corrosion with dendritic formation usually occurs at the grain boundary. This is due to defects and a higher copper content at the grain boundary. The impact of copper bimetallic contact on aluminum corrosion was explored by sputtering copper microdots on aluminum substrate. Copper micropattern screening revealed that the corrosion is activated on the Al/Cu interface area and driven by the large potential difference; it was also seen to proceed at much higher rates than those observed with bare aluminum. Direct galvanic current measurement, linear sweep voltammetry (LSV), and Tafel plots are used to measure corrosion current and potential. Hydrogen gas evolution was also observed (for the first time) in Cu/Al bimetallic interface in areas of active corrosion. Mechanistic insight that leads to effective prevention of aluminum bond pad corrosion is explored and discussed. Micropattern corrosion screening identified hydrogen evolution and bimetallic interface as the root cause of Al pad corrosion that leads to Cu ball lift-off, a fatal defect, in Cu wire bonded device. Complete corrosion inhibition can be achieved by strategically disabling the mutually coupled cathodic and anodic reaction cycles.

碩士
國立清華大學
電機工程學系
102
Many odors are not suitable for human to smell, such as poisonous and exhausted gases. In addition, olfaction is different from person to person. Compare to the traditional gas detection instrument, an electronic nose (E-nose) system has various advantages including small size, low cost, low power, quantization of olfaction, and the capability of being exposed to dangerous gases. Therefore, it can be applied to quality control of foods, environmental monitoring, pollution measurement and disease diagnosis, etc. E-nose system is composed of a gas sensor array, a signal acquisition circuit and a pattern recognition system. Conducting polymer sensor is one of the chemiresistive gas sensors. It has the advantages of working at room temperature, high sensitivity (about a few ppm), and its readout circuit is simple, which would be suitable for portable devices. However, the sensor resistance could be easily affected by temperature, humidity, and background odors. In addition, the resistances of each sensor in the sensor array are not the same after the deposition of different sensing materials. Therefore, an adaptive interface circuit is required to cancel the baseline drift and read the sensor signal. Three types of adaptive interface circuits fabricated by TSMC 0.18μm CMOS 1P6M processes would be introduced in this paper: semi-digital type, digital type and analog type. Simulation and measurement result of these three interface circuits would be presented and be compared. Lastly, an external conductive polymer gas sensor array connected with adaptive interface circuit was exposed to different odors, and the results were presented. Gas sensors were respectively integrated with the semi-digital type and digital type interface circuits on the same chip.

碩士
國立清華大學
電機工程學系
98
Electronic nose system is the world's popular field of studies, it can be widely applied to various industries and daily life. This thesis hopes to increase the convenience of the electronic nose system, the applicable site of electronic nose system can’t be constraints, and low cost. Surface Acoustic Wave sensors with high sensitivity, fast response, etc., is very suitable for as gas sensors. Use of non-continuous surface acoustic wave gas sensor array measured power consumed by the lower, extend the operating hours of portable devices. It realization of SAW sensor interface circuits by using 0.18μm CMOS process in this work. The three types of circuits are digital, analog and mixed-mode SAW array interface circuit, the performance of the mixed-mode circuits is the best one, the power consumption is only 1.48mW, the resolution is 10Hz, suitable for the SAW output frequency of about 100MHz sensor array. The interface can be combined with wireless transmission to send data to the receiver storage and analysis.

Internet of Things is expanding to the areas such as healthcare, home management, industrial, agriculture, and becoming pervasive in our life, resulting in improved efficiency, accuracy and economic benefits. Smart sensors with embedded interfacing integrated circuits (ICs) are important enablers, hence, variety of smart sensors are required. However, each type of sensor requires specific interfacing chips, which divides the huge market of sensors’ interface chips into lots of niche markets, resulting in high develop cost and long time-to-market period for each type. Software defined sensor is regarded as a promising solution, which is expected to use a flexible interface platform to cover different sensors, deliver specificity through software programming, and integrate easily into the Internet of Things. In this work, research is carried out on the design and implementations of ultra low power analog interface circuits toward software defined sensors for healthcare services based on Internet of Things.    This thesis first explores architectures and circuit techniques for energy-efficient and flexible analog to digital conversion. A time-spreading digital calibration, to calibrate the errors due to finite gain and capacitor mismatch in multi-bit/stage pipelined converters, is developed with short convergence time. The effectiveness of the proposed technique is demonstrated with intensive simulations. Two novel circuit level techniques, which can be combined with digital calibration techniques to further improve the energy efficiency of the converters, are also presented. One is the Common-Mode-Sensing-and-Input-Interchanging (CSII) operational-transconductance-amplifier (OTA) sharing technique to enable eliminating potential memory effects. The other is a workload-balanced multiplying digital-to-analog converter (MDAC) architecture to improve the settling efficiency of a high linear multi-bit stage. Two prototype converters have been designed and fabricated in 0.13 μm CMOS technology. The first one is a 14 bit 50 MS/s digital calibrated pipelined analog to digital converter that employs the workload-balanced MDAC architecture and time-spreading digital calibration technique to achieve improved power-linearity tradeoff. The second one is a 1.2 V 12 bit 5~45 MS/s speed and power-scalable ADC incorporating the CSII OTA-sharing technique, sample-and-hold-amplifier-free topology and adjustable current bias of the building blocks to minimize the power consumption. The detailed measurement results of both converters are reported and deliver the experimental verification of the proposed techniques.     Secondly, this research investigates ultra-low-power analog front-end circuits providing programmability and being suitable for different types of sensors. A pulse-width- -modulation-based architecture with a folded reference is proposed and proven in a 0.18 μm technology to achieve high sensitivity and enlarged dynamic range when sensing the weak current signals. A 8-channel bio-electric sensing front-end, fabricated in a 0.35 μm CMOS technology is also presented that achieves an input impedance of 1 GΩ, input referred noise of 0.97 Vrms and common mode rejection ratio of 114 dB. With the programmable gain and cut-off frequency, the front-end can be configured to monitor for long-term a variety of bio-electric signals, such as electrooculogram (EOG), electromyogram (EMG), electroencephalogram (EEG) and electrocardiogram (ECG) signals. The proposed front-end is integrated with dry electrodes, a microprocessor and wireless link to build a battery powered E-patch for long-term and continuous monitoring. In-vivo test results with dry electrodes in the field trials of sitting, standing, walking and running slowly, show that the quality of ECG signal sensed by the E-patch satisfies the requirements for preventive cardiac care.    Finally, a wireless multimodal bio-electric sensor system is presented. Enabled by a customized flexible mixed-signal system on chip (SoC), this bio-electric sensor system is able to be configured for ECG/EMG/EEG recording, bio-impedance sensing, weak current stimulation, and other promising functions with biofeedback. The customized SoC, fabricated in a 0.18 μm CMOS technology, integrates a tunable analog front-end, a 10 bit ADC, a 14 bit sigma-delta digital to current converter, a 12 bit digital to voltage converter, a digital accelerator for wavelet transformation and data compression, and a serial communication protocol. Measurement results indicate that the SoC could support the versatile bio-electric sensor to operate in various applications according to specific requirements.

QC 20151221

Recently, there has been an increasing interest in the electronics world for those aspects related to semiconducting gas sensor (SGS) materials. In view of the increasingly strict legal limits for pollutant gas emissions, there is a great interest in developing high performance gas sensors for applications such as controlling air pollution and exhaust gases in automotive industry. In this way, semiconductor gas sensors offer good advantages with respect to other gas sensor devices, due to their simple implementation, low cost and good stability and sensitivity. The first part of the thesis is dedicated to the synthesis, film structural and sensitivity study of the Tin Oxide film deposited by RF sputtering, doped with noble metal Palladium (Pd). Effects on the Gas Sensitivity due to the deposition parameters like thickness of the film, Substrate temperature, Ar /O2 ratio of the sputtering environment, annealing temperature and duration and doping metal weight % into the Tin Oxide films are studied and the results are shown in detail. The sensitivity and selectivity of the gas sensing film is decided by the operating temperature i.e. the temperature of the gas sensing film while it is in the target gas ambience, Microheaters happen to be the very important component in the gas sensor especially with wide band gap semiconducting metal oxides films such as tin oxide, gallium oxide or indium oxides. Other than gas sensing microheater also finds applications in many areas like thermal dip pen nanolithography, polymerase chain reaction (PCR), fluid pumping with bubbles, in vitro fertilization etc. So in this report due importance was given for the design and fabrication of the microheater. Microheaters are the most power consuming element of the integrated Gas sensors. This is also an important reason for the extensive microheater work in this research. Six different heater patterns were simulated by considering low power and temperature uniformity as an important goals. Among them the best three patterns named Double spiral, “Fan” Shape and “S” shape were chosen for fabrication and both thermal and electrical characterization results of them were presented in detail in the Microheater section of the thesis. It is believed that the intelligent design and integration of the electronic circuitry (for drive, signal conditioning/compensation, and read-out) with the gas sensing element can mitigate some of the significant issues inherent in solid-state gas sensors, such as strong temperature and humidity dependence, signal drift, aging, poisoning, and weak selectivity. The sensitivity of the gas sensors which has been indicated as the dynamic change of resistance in wide range should be read out properly. Towards this aim a low cast high efficient readout circuit is designed and implemented. Temperature monitoring and controlling is a key phenomenon in the metal Oxide based gas sensors since the selectivity mainly depends on the operating temperature of the sensing film. So focus was also shown on the design and implementation of the temperature monitoring and control unit, which been presented in the last part of this thesis.

Recently, there has been an increasing interest in the electronics world for those aspects related to semiconducting gas sensor (SGS) materials. In view of the increasingly strict legal limits for pollutant gas emissions, there is a great interest in developing high performance gas sensors for applications such as controlling air pollution and exhaust gases in automotive industry. In this way, semiconductor gas sensors offer good advantages with respect to other gas sensor devices, due to their simple implementation, low cost and good stability and sensitivity. The first part of the thesis is dedicated to the synthesis, film structural and sensitivity study of the Tin Oxide film deposited by RF sputtering, doped with noble metal Palladium (Pd). Effects on the Gas Sensitivity due to the deposition parameters like thickness of the film, Substrate temperature, Ar /O2 ratio of the sputtering environment, annealing temperature and duration and doping metal weight % into the Tin Oxide films are studied and the results are shown in detail. The sensitivity and selectivity of the gas sensing film is decided by the operating temperature i.e. the temperature of the gas sensing film while it is in the target gas ambience, Microheaters happen to be the very important component in the gas sensor especially with wide band gap semiconducting metal oxides films such as tin oxide, gallium oxide or indium oxides. Other than gas sensing microheater also finds applications in many areas like thermal dip pen nanolithography, polymerase chain reaction (PCR), fluid pumping with bubbles, in vitro fertilization etc. So in this report due importance was given for the design and fabrication of the microheater. Microheaters are the most power consuming element of the integrated Gas sensors. This is also an important reason for the extensive microheater work in this research. Six different heater patterns were simulated by considering low power and temperature uniformity as an important goals. Among them the best three patterns named Double spiral, “Fan” Shape and “S” shape were chosen for fabrication and both thermal and electrical characterization results of them were presented in detail in the Microheater section of the thesis. It is believed that the intelligent design and integration of the electronic circuitry (for drive, signal conditioning/compensation, and read-out) with the gas sensing element can mitigate some of the significant issues inherent in solid-state gas sensors, such as strong temperature and humidity dependence, signal drift, aging, poisoning, and weak selectivity. The sensitivity of the gas sensors which has been indicated as the dynamic change of resistance in wide range should be read out properly. Towards this aim a low cast high efficient readout circuit is designed and implemented. Temperature monitoring and controlling is a key phenomenon in the metal Oxide based gas sensors since the selectivity mainly depends on the operating temperature of the sensing film. So focus was also shown on the design and implementation of the temperature monitoring and control unit, which been presented in the last part of this thesis.

碩士
國立交通大學
電機與控制工程系所
92
Traditionally, the pin electronics (PE) card circuits of a tester consists of several components, such as reference voltage IC, driver/receiver IC and etc on a print circuit board (PCB). It uses the bus to connect all the components. Hence, the operation speed of PE is limited and the area of complete architecture is large. In this thesis, we target CMOS chip for our device under test circuit to design the PE card circuits. Owing to the operating frequency is more and more fast, we must use the high-speed interface to transmit or receive the data, such as low-voltage positive-reference emitter-coupled-logic (LVPECL) interface standard and low voltage differential signals (LVDS) interface standard. For driver part, we use tri-state buffer with parasitic inductance to achieve the speed requirement and the driving capabilities as the spec. We use the window comparator to receive the signal from the device under test (DUT). It will be divided into three voltage level ranges to compare whether the signal is valid or not. For dynamic load, due to the switching speed, we will still use the diode-bridge structure to be the voltage-comparison circuit. As for the current source, we use 6-bit digital signals to control how much current we need. And the all the reference voltages of this chip are provided by a 6-bit DAC and some decoders. Finally, the complete circuits have been designed and implemented by TSMC 0.18um Mixed Signal 1p6m 1.8V/3.3V process technology. Pre- and post-simulation will verify the feasibility of the design.

Dissertação de Mestrado Integrado em Engenharia Física apresentada à Faculdade de Ciências e Tecnologia
Este trabalho incide sobre sistemas eletrónicos extensíveis (\textit{Stretchable}) fabricados com compostos condutores constituídos por micropartículas/microflocos de prata dispersos numa matriz de Polidimetilsiloxano.Num primeiro passo, vários tipos de compostos baseados em prata serão testados e comparados. Isto inclui partículas com diferentes geometrias, nomeadamente micropartículas e microflocos de prata, bem como micropartículas de níquel e ferrite revestidas com prata. Do composto resultante, designado AgPDMS, espera-se que seja um bom condutor e, mais, que mantenha esta característica mesmo quando elongado. O limiar de percolação para cada um destes tipos de partículas será obtido experimentalmente, e a estabilidade das propriedades elétricas do tipo de partícula selecionado será avaliada. De seguida, três métodos de padronização serão avaliados, nomeadamente impressão por \textit{stencil}, serigrafia e moldagem. O objetivo seguinte será reduzir a área dos circuitos desenvolvidos, quer reduzindo a dimensão dos elementos do circuito quer fabricando circuitos com várias camadas. Para fabricar circuitos de várias camadas será usado um método baseado em ablação com laser para criar vias que ligam electricamente camadas adjacentes. Em seguida, métodos para integrar componentes rígidas em circuitos extensíveis serão testados. Será ainda realizada caracterização eletromecânica de amostras fabricadas usando os materias e métodos selecionados no decorrer deste trabalho.Para terminar, serão apresentados dois sistemas electrónicos extensíveis fabricados no ISR, como prova de conceito. O primeiro é um \textit{touchpad} capacitivo extensível, e o segundo um sensor ECG sem fios extensível.
This work focuses on stretchable electronics systems, composed of silver-based conductive composites as the conductive material and Polydimethylsiloxane (PDMS) as the stretchable substrate material.First, as a filler for PDMS-based conductive composites, various types of silver particles will be evaluated. This includes silver particles and silver flakes with different geometries, as well as silver-coated nickel/ferrite particles. The resulting composite, called AgPDMS, should be conductive and also tolerate strain without losing conductivity. The percolation threshold for each of these particle types is obtained experimentally, and the stability over time of conductivity for the selected particle type is evaluated. After this, three patterning methods are evaluated, namely stencil printing, screen printing and moulding.The second goal of this work is to reduce the circuit footprint by both reducing feature dimensions and fabricating multilayer AgPDMS stretchable circuits. To fabricate multilayer circuits, a method based on laser ablation is used for creating vias between layers.After this, methods for integrating flexible and rigid components into soft circuits will be assessed.Thorough electromechanical characterisation of samples fabricated using the selected materials and methods will be performed.To conclude, two stretchable electronics systems fabricated at ISR will be presented as proof-of-concept. This includes a multilayer capacitive stretchable touchpad and an ECG sensor.
FCT

Thesis (M.Sc.)--University of Alberta, 2010.
A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Power Engineering and Power Electronics, Department of Electrical and Computer Engineering. Title from pdf file main screen (viewed on June 13, 2010). Includes bibliographical references.

碩士
國立清華大學
電機工程學系
98
Many applications use the electronic nose (Enose) system, such as environmental monitoring, food processing, pollution measurement and medical diagnosis. The ability to monitor and identify various chemical gases is also valuable. Although the sensing capabilities of our noses are well beyond that achievable by any existing instrument, many applications require non-human odor detecting ability. Compared with a traditional gas chromatograph-mass spectrometer (GC-MS), electronic nose systems have the advantage of being smaller, more portable, and cost economic. The research focuses on an integrated conducting polymer gas sensor array and its adaptive interface circuit compatible with standard CMOS processes for an electronic nose chip. The sensors use polymer-carbon black composites, which swell reversibly and create resistance change upon exposure to chemical vapors. The initial resistances of sensors are influenced by temperature or humidity. Therefore, an adaptive interface circuit is proposed to cancel the baseline signal drift. With the progress of MEMS process, there are many researches about miniature conducting polymer gas sensors. But most of the researches could not compatible with standard CMOS processes. We proposed the conducting polymer gas sensor array that compatible with standard CMOS processes. It is very important for the portable electronic nose system. Using standard CMOS process to integrate sensors and circuits can achieve small size, low-power, low noise and low cost.

Thin Film Transistors (TFTs) are widely used in large area electronics because they offer the advantage of low cost fabrication and wide substrate choice. TFTs have been conventionally used for switching applications in large area display arrays. But when it comes to designing a sensor actuator system on a flexible substrate comprising entirely of organic and inorganic TFTs, there are two main challenges – i) Fabrication of complementary TFT devices is difficult ii) TFTs have a drift in their threshold voltage (VT) on application of gate bias. Also currently there are no circuit simulators in the market which account for the effect of VT drift with time in TFT circuits. The first part of this thesis focuses on integrating the VT shift model in the commercially available AIM-Spice circuit simulator. This provides a new and powerful tool that would predict the effect of VT shift on nodal voltages and currents in circuits and also on parameters like small signal gain, bandwidth, hysteresis etc. Since the existing amorphous silicon TFT models (level 11 and level 15) of AIM-Spice are copyright protected, the open source BSIM4V4 model for the purpose of demonstration is used. The simulator is discussed in detail and an algorithm for integration is provided which is then supported by the data from the simulation plots and experimental results for popular TFT configurations. The second part of the thesis illustrates the idea of using negative feedback achieved via contact resistance modulation to minimize the effect of VT shift in the drain current of the TFT. Analytical expressions are derived for the exact value of resistance needed to compensate for the VT shift entirely. Circuit to realize this resistance using TFTs is also provided. All these are experimentally verified using fabricated organic P-type Copper Phthalocyanine (CuPc) and inorganic N-type Tin doped Zinc Oxide (ZTO) TFTs. The third part of the thesis focuses on building a robust amplifier using these TFTs which has time invariant DC voltage level and small signal gain at the output. A differential amplifier using ZTO TFTs has been built and is shown to fit all these criteria. Ideas on vertical routing in an actual sensor actuator interface using this amplifier have also been discussed such that the whole system may be “tearable” in any contour. Such a sensor actuator interface can have varied applications including wrap around thermometers and X-ray machines.

Thin Film Transistors (TFTs) are widely used in large area electronics because they offer the advantage of low cost fabrication and wide substrate choice. TFTs have been conventionally used for switching applications in large area display arrays. But when it comes to designing a sensor actuator system on a flexible substrate comprising entirely of organic and inorganic TFTs, there are two main challenges – i) Fabrication of complementary TFT devices is difficult ii) TFTs have a drift in their threshold voltage (VT) on application of gate bias. Also currently there are no circuit simulators in the market which account for the effect of VT drift with time in TFT circuits. The first part of this thesis focuses on integrating the VT shift model in the commercially available AIM-Spice circuit simulator. This provides a new and powerful tool that would predict the effect of VT shift on nodal voltages and currents in circuits and also on parameters like small signal gain, bandwidth, hysteresis etc. Since the existing amorphous silicon TFT models (level 11 and level 15) of AIM-Spice are copyright protected, the open source BSIM4V4 model for the purpose of demonstration is used. The simulator is discussed in detail and an algorithm for integration is provided which is then supported by the data from the simulation plots and experimental results for popular TFT configurations. The second part of the thesis illustrates the idea of using negative feedback achieved via contact resistance modulation to minimize the effect of VT shift in the drain current of the TFT. Analytical expressions are derived for the exact value of resistance needed to compensate for the VT shift entirely. Circuit to realize this resistance using TFTs is also provided. All these are experimentally verified using fabricated organic P-type Copper Phthalocyanine (CuPc) and inorganic N-type Tin doped Zinc Oxide (ZTO) TFTs. The third part of the thesis focuses on building a robust amplifier using these TFTs which has time invariant DC voltage level and small signal gain at the output. A differential amplifier using ZTO TFTs has been built and is shown to fit all these criteria. Ideas on vertical routing in an actual sensor actuator interface using this amplifier have also been discussed such that the whole system may be “tearable” in any contour. Such a sensor actuator interface can have varied applications including wrap around thermometers and X-ray machines.

Trabalho de Projeto do Mestrado Integrado em Engenharia Biomédica apresentado à Faculdade de Ciências e Tecnologia
Circuitos eletrónicos convencionais são compostos por materiais rígidos e quebradiços. No entanto, orgãos biológicos são fundamentalmente moles (soft). Este desfasamento evidente despertou interesse no campo da electrónica deformável, que se foca no desenvolvimento de materiais e métodos de fabrico para circuitos cujas propriedades mecânicas se assemelham às dos tecidos biológicos. Estes esforços têm sido direcionados para a introdução de novos métodos e técnicas de fabrico de formas deformáveis de elétrodos, conectores e sensores. Porém, a funcionalidade de circuitos deformáveis ainda está dependente da utilização de tecnologias de estado sólido (SST), tais como díodos emissores de luz (LEDs) e circuitos integrados (ICs), para aquisição, processamento e comunicação de dados. A integração de SST em circuitos extensíveis introduz uma incompatibilidade mecânica no sistema, o que leva à falha prematura e/ou perda de funcionalidade do circuito quando é aplicada uma deformação. Apesar deste ser o maior obstáculo contra o fabrico escalável de circuitos extensíveis, poucos esforços têm sido direcionados para o combater de forma eficiente, já que as soluções apresentadas são geralmente complexas e trabalhosas. Este trabalho propõe um novo método de interface de componentes rígidos com circuitos deformáveis que lhes permite resistir a um distensão máxima recorde de >600%, 3x superior a qualquer outra técnica publicada. Os circuitos são fabricados através de deposição de uma tinta bifásica inovadora composta por Ag-EGaIn-SIS sobre um copolímero de bloco de estireno-isopreno (SIS). Em seguida, microchips SMD são colocados sobre as conexões utilizando uma máquina pick and place. Uma técnica inovadora de exposição de vapor de tolueno é depois utilizada para causar uma transição duro-mole tanto no substrato de SIS, como na tinta composta por SIS. O microchip consegue então penetrar e aderir à tinta e a estrutura do componente é envolvida na íntegra pelo substrato adesivo. Além de possibilitar a integração de microchips, o tratamento de vapor de tolueno melhora a percolação do compósito condutivo, o que resulta num aumento de 2x na condutividade das pistas do circuito. Exposição ao vapor permite ainda eliminar defeitos como micro-fendas presentes no substrato, possibilitando assim atingir distensões superiores. Para caracterizar a técnica analisou-se um conjunto de parâmetros como a tolerância máxima de distensão e resistência à fadiga. Recorreu-se ainda à microscopia eletrónica de varredura e microscopia ótica para investigar e compreender os mecanismos subjacentes à integração dos components rígidos. Além destas vantagens face ao estado de arte, o método descrito é consideravelmente mais simples que outras técnicas previamente publicadas, constituindo assim um passo importante no fabrico automático e escalável de circuitos deformáveis com integração de microchips. O método foi desenvolvido e demonstrado com sucesso através de um case-study que consistiu em desenvolver um circuito extensível para medição da temperatura da pele. Este circuito foi depois transferido para um tecido de modo a formar um máscara wearable para medição de temperatura do utilizador.
Conventional electronic systems are composed of rigid and brittle materials. Biological organs however are mostly made of soft materials. This conspicuous mismatch sparked interest in the field of stretchable electronics, which focuses on materials and methods for fabrication of thin, soft, and stretchable circuits that can interface a host surface, for instance the human epidermis, and keep their functionality despite the dynamic morphology of the host system. Such efforts mostly focused on the introduction of materials and methods for patterning of stretchable electrodes, interconnects, and sensors. However, the ultimate functionality of these systems remains dependent of solid-state technology (SST), from simple light emitting diodes (LEDs), to packaged integrated circuits (ICs) for data acquisition, processing and communication. Integration of SST into these circuits induces a drastic mechanical mismatch, resulting in premature failure and/or loss of the circuit functionality when strain is applied to the systems. Even though this problem is the main bottleneck against scalable fabrication of stretchable electronics, very few works tried to address it. In addition, the previously presented solutions are complex, labor-intensive and require many fabrication steps. In this work, we proposed a novel method for interfacing SST components into stretchable circuits that can withstand a record-breaking maximum strain tolerance of >600% of strain, 3x higher than any previously reported technique. Circuits are fabricated by printing a novel biphasic Ag-EGaIn-SIS ink over a Styrene-isoprene block copolymers (SIS) substrate. Then, SMD microchips are placed over the interconnects using a pick and place machine. This is followed by an innovative technique of toluene vapor exposure that provokes a hard-soft transition both in the SIS substrate, and in the SIS-containing ink. Then, the microchip penetrates and adheres to the ink, and the body of the component gets surrounded by the adhesive substrate entirely on all of its perimeter. In addition to the microchip integration, the vapor treatment improves the percolation of the conductive composite, resulting in a 2x increment in the conductivity of the printed traces. Furthermore, vapor exposure eliminates defects and micro-cracks present in the substrate, allowing for a higher strain tolerance. To characterize the technique, we analyzed a set of parameters, including maximum strain tolerance and fatigue tolerance. SEM and optical microscopy were as well used to inspect the underlying mechanisms that lead to the integration of the rigid components. In addition to these advantages over state-of-the-art, this method is considerably simpler than previously reported methods, thus paving an important step toward scalable and automated fabrication of microchip-integrated stretchable circuits. An example of application was demonstrated through fabrication of a microchip-integrated stretchable circuit that could measure the skin temperature, or that can be transferred to a textile mask for acquisition and display of the temperature.
Outro - Projeto "CMU-Portugal WoW" (Referência: 45913) com o apoio do Fundo Europeu de Desenvolvimento Regional (ERDF) e do Estado Português através do Portugal2020 e COMPETE 2020.
Outro - Projeto “Add.Additive” (Referência: 59563), financiado pelo Fundo Europeu de Desenvolvimento Regional (ERDF), através do “Programa Operacional Competitividade e Internacionalizacão” (POCI-01-0247-FEDER-024533)
Outro - Projeto Dermotronics” (Reference: 31784), financiado pelos ”Fundos Europeus Estruturais e de Investimento” (FEEI), através do ”Programa Operacional Regional do Centro”.

by Siu Hing Kee Stanley.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1994.
Includes bibliographical references (leaves 87-88).
Abstract --- p.ii
Acknowledgments --- p.iii
Chapter 1 --- Introduction --- p.1-1
Chapter 1.1 --- Introduction --- p.1-1
Chapter 1.2 --- Background --- p.1-2
Chapter 1.3 --- Thesis Organization --- p.1-4
Chapter 2 --- Synthesis of Common Structures in a Microcontroller --- p.2-1
Chapter 2.1 --- Limitation of Synthesis Tools --- p.2-1
Chapter 2.2 --- Synthesizable VHDL for Common Structures --- p.2-2
Chapter 2.2.1 --- Counter --- p.2-3
Chapter 2.2.2 --- Set-Reset Latch --- p.2-6
Chapter 2.2.3 --- D Latch --- p.2-9
Chapter 2.2.4 --- D Flip-flop --- p.2-12
Chapter 2.2.5 --- Multiplexor --- p.2-13
Chapter 2.2.6 --- Shift Register --- p.2-15
Chapter 2.2.7 --- Signal Affected by Two Signal Edges --- p.2-18
Chapter 2.2.8 --- Combinational Feedback --- p.2-19
Chapter 2.2.9 --- Short Pulses --- p.2-21
Chapter 2.2.10 --- Register Transfer Logic --- p.2-22
Chapter 2.2.11 --- Status Flag --- p.2-26
Chapter 2.2.12 --- Register Access --- p.2-30
Chapter 2.2.13 --- Clock Divider --- p.2-34
Chapter 2.2.14 --- Communication among Processes --- p.2-36
Chapter 3 --- Synthesis of Components of a Microcontroller --- p.3-1
Chapter 3.1 --- Timer --- p.3-1
Chapter 3.2 --- Serial Peripheral Interface (SPI) --- p.3-9
Chapter 3.3 --- Serial Communication Interface (SCI) --- p.3-16
Chapter 3.4 --- Parallel I/O Port --- p.3-21
Chapter 3.5 --- 6805CPU --- p.3-22
Chapter 3.5.1 --- State Counter --- p.3-23
Chapter 3.5.2 --- Instruction Decoding and Execution Unit --- p.3-24
Chapter 3.5.3 --- Interrupt Logic --- p.3-25
Chapter 3.5.4 --- Instruction Register --- p.3-27
Chapter 4 --- VHDL Coding and Synthesis --- p.4-1
Chapter 4.1 --- Controlling Synthesis by VHDL Coding --- p.4-1
Chapter 4.1.1 --- Structure Control --- p.4-2
Chapter 4.1.2 --- Feedback Path Control --- p.4-2
Chapter 4.1.3 --- Control of Use of Storage --- p.4-2
Chapter 4.1.4 --- Timing Control --- p.4-3
Chapter 4.2 --- Consequences of the Writing Guidelines --- p.4-5
Chapter 5 --- Interface Tool for Generation of VHDL for a Microcontroller --- p.5-1
Chapter 5.1 --- Features --- p.5-1
Chapter 5.2 --- Construction --- p.5-1
Chapter 5.3 --- Illustration --- p.5-3
Chapter 5.4 --- Data Structure --- p.5-5
Chapter 5.4.1 --- Design List --- p.5-6
Chapter 5.4.2 --- Instance Data --- p.5-6
Chapter 5.4.3 --- Instance List --- p.5-8
Chapter 5.4.4 --- Register Data --- p.5-9
Chapter 5.4.5 --- Dialogs and Functions --- p.5-10
Chapter 5.5 --- VHDL Generator for Individual Component --- p.5-11
Chapter 5.6 --- VHDL Generator for the Whole Microcontroller --- p.5-14
Chapter 6 --- Conclusion --- p.6-1
Bibliography --- p.B-1
Appendix --- p.A-1

Trend towards downsizing the product size and at the same time to bring more functionality in electronic products, demands electrically interconnecting several miniaturized electronic components with high counts of I\Os (Input/Out put) on smaller and smaller size printed wiring boards [PWB]. These miniature components occupy lower foot print area but require higher routing interconnection densities. However, the conventional multilayer board technologies exhibit limitations when there is need to connect very high I\O components such as ball grid arrays, which require blind and buried interconnections within the multilayer mono-block. This limitation has given raise to newer methods of multi layer construction. Build–up multilayer PWB is now the technology of choice for enhanced routing capability including blind and buried interlayer connections. Build up methods are based on making very small vias within dielectric layers followed by metalisation. Typically blind and buried vias are very small, and hence called “micro vias” connecting the layers selectively within the multilayer mono-block. Buried vias make the interconnection between the consecutive layers, and blind vias connect the surface layers to any one of the interior layers in the build up multilayer board. If the blind vias are filled with a dielectric, the entire top and bottom surface area becomes available for high -density component mounting. The crux in build up board technologies is the method of creating micro-holes; a micro hole is a hole, which is less than 150 micro meter in diameter. Efforts are made to replace existing metalising techniques with “paste filling” methodologies, which would result in “SOLID CONDUCTING VIAS” CALLED AS “MICRO -INTERCONNECTS” The work reported in this thesis aims at demonstrating one such innovative ‘solid conducting via’ formation without using any of the known micro-hole formation techniques. Based on the results obtained some useful conclusions have been drawn which will perhaps go a long way in the name of “PRINTED PILLAR TECHNOLOGY” a novel methodology for building multilayer suitable for very high I\O components such as “ball grid arrays.”

Trend towards downsizing the product size and at the same time to bring more functionality in electronic products, demands electrically interconnecting several miniaturized electronic components with high counts of I\Os (Input/Out put) on smaller and smaller size printed wiring boards [PWB]. These miniature components occupy lower foot print area but require higher routing interconnection densities. However, the conventional multilayer board technologies exhibit limitations when there is need to connect very high I\O components such as ball grid arrays, which require blind and buried interconnections within the multilayer mono-block. This limitation has given raise to newer methods of multi layer construction. Build–up multilayer PWB is now the technology of choice for enhanced routing capability including blind and buried interlayer connections. Build up methods are based on making very small vias within dielectric layers followed by metalisation. Typically blind and buried vias are very small, and hence called “micro vias” connecting the layers selectively within the multilayer mono-block. Buried vias make the interconnection between the consecutive layers, and blind vias connect the surface layers to any one of the interior layers in the build up multilayer board. If the blind vias are filled with a dielectric, the entire top and bottom surface area becomes available for high -density component mounting. The crux in build up board technologies is the method of creating micro-holes; a micro hole is a hole, which is less than 150 micro meter in diameter. Efforts are made to replace existing metalising techniques with “paste filling” methodologies, which would result in “SOLID CONDUCTING VIAS” CALLED AS “MICRO -INTERCONNECTS” The work reported in this thesis aims at demonstrating one such innovative ‘solid conducting via’ formation without using any of the known micro-hole formation techniques. Based on the results obtained some useful conclusions have been drawn which will perhaps go a long way in the name of “PRINTED PILLAR TECHNOLOGY” a novel methodology for building multilayer suitable for very high I\O components such as “ball grid arrays.”

The oil and gas industry faces a lack of compact drilling devices capable of performing horizontal drilling maneuvers in depleted or abandoned wells in order to enhance oil recovery. The purpose of this project was to design and develop a smart sensing system that can be later implemented in compact drilling devices used to perform horizontal drilling to enhance oil recovery in wells. A smart sensor is the combination of a sensing element (sensor) and a microprocessor. Hence, a smart sensing system is an arrangement that consists of different sensors, where one or more have smart capabilities. The sensing system was built and tested in a laboratory setting. For this, a test bench was used as a case study to simulate the operation from a micro-drilling device. The smart sensing system integrated the sensors essential for the direct operational measurements required for the robot. The focus was on selecting reliable and sturdy components that can handle the operation Down the Hole (DTH) on the final lateral micro-drilling robot. The sensing system's recorded data was sent to a microcontroller, where it was processed and then presented visually to the operator through a User Interface (UI) developed in a cloud-based framework. The information was filtered, processed, and sent to a controller that executed commands and sent signals to the test bench’s actuators. The smart sensing system included novel modules and sensors suitable for the operation in a harsh environment such as the one faced in the drilling process. Furthermore, it was designed as an independent, flexible module that can be implemented in test benches with different settings and early robotic prototypes. The outcome of this project was a sensing system able to provide robotic drilling devices with flexibility while providing accurate and reliable measurements during their operation.