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Artykuły w czasopismach na temat „Mems, piezoelectric, electric propulsion”
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Dean, Robert N., Colin B. Stevens i John J. Tatarchuk. "A Current-Controlled PCB Integrated MEMS Tilt Mirror". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2014, DPC (1.01.2014): 000588–608. http://dx.doi.org/10.4071/2014dpc-ta32.
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Introduction: MEMS Tilt Mirror - a miniature planar micro-mirror that can experience a 1-D or 2-D tilt in response to a control signal. Commonly used technologies- electrostatic, piezoelectric, electrothermal bimorph. Applications - laser beam steering, interferometers, dynamic signal analyzers, opticcal cross-connect switches. This paper describes the design, key features and applications of a System On Chip (SOC) ASIC (Application Specific Integrated Circuit) that has been developed under an Air Force SBIR program. The SOC device has been implemented by Honeywell International using their High Temperature SOI (Silicon On Insulator) Process. The objective of the Air Force SBIR program {1} was to investigate the potential for use of available High Temperature SOI technology devices for aerospace propulsion control system applications. Several prototype designs implemented by Embedded Systems LLC (ES-LLC) using available SOI devices identified significant limitations in the performance capability and level of integration. The diversity of propulsion system interfacing requirements demanded generic solutions so that they could be deployed in multiple applications without changes. The available devices were also not affordable due to the limited size of the market for this technology. It was therefore decided to develop a generic, reconfigurable SOC chipset {2} that could be implemented using Honeywell's HT200 Family of ASIC Gate Arrays. The paper will describe the architecture and key features of the SOC chipset solution which can be reconfigured to interface with most typical aerospace control system sensors and actuators. The SOC chipset captures all of the necessary functions required to interface with sensors such as RTD (resistance Temperature Detectors), Strain Gauges (SG) and thermocouples (TC), mass flow, speed and LVDT (Linear Variable Differential Transducer) position. The excitation circuitry required to power these interfaces is embedded in the chipset and can be reconfigured as required. The SOC chipset also contains all of the pre- and post-processing functions to convert electrical signals into digital words and send them on a data bus under the control of a host microprocessor. The SOC chipset can be powered from a Mil-Std 704F compliant power source or a conditioned DC power source. The SOC chipset when combined with other external devices can be implemented as a “Smart Node” for localized management of sensors and actuators as a part of a distributed architecture or used as a scalable building block in a more complex function such as a FADEC (Full Authority Digital Engine Control). The SOC chipset thus completes the set of all High Temperature SOI Integrated circuits required for implementation of typical Smart Nodes. It is believed that the versatility of the SOC chipset makes it a well suited, affordable, scalable building block for not only aerospace controls but also for diverse applications such as down-hole drilling, energy exploration, wind farms etc. where high temperature electronics is required.
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Leland, Eli S., Richard M. White i Paul K. Wright. "Design and Fabrication of a MEMS AC Electric Current Sensor". Advances in Science and Technology 54 (wrzesień 2008): 350–55. http://dx.doi.org/10.4028/www.scientific.net/ast.54.350.
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The need for energy efficiency combined with advances in compact sensor network technologies present an opportunity for a new type of sensor to monitor electricity usage in residential and commercial environments. A novel design for a self-powered, proximity based AC electric current sensor has been developed. This sensor device is constructed of a piezoelectric cantilever with a permanent magnet mounted to the cantilever's free end. When the sensor is placed in proximity to a wire carrying AC electric current, the permanent magnet couples to the wire's alternating magnetic field, deflecting the piezoelectric cantilever and thus producing a sinusoidal voltage proportional to the current being measured. Analytical models were developed to predict the magnetic forces and piezoelectric voltage output pertaining to this design. MEMS-scale cantilevers are currently under development using a three-mask process and aluminum nitride as the active piezoelectric material. Very small (300 μm) permanent magnets have been dispenser-printed using magnetic powders in a polymer matrix. Previously presented meso-scale (2-3 cm3) prototype devices exhibited sensitivities of 74 mV/A, while simulations suggest MEMS device sensitivity of 2-4 mV/A.
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Kannan S, Abdul Aziz Khan J. ,. Shanmugaraja P. ,. "SIMULATION AND ANALYSIS OF DIFFERENT PIEZOELECTRIC MATERIALS IN MEMS CANTILEVER FOR ENERGY HARVESTING". INFORMATION TECHNOLOGY IN INDUSTRY 9, nr 1 (18.03.2021): 1321–28. http://dx.doi.org/10.17762/itii.v9i1.274.
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MEMS Energy Harvesting(EH) devices are excepted to grow in the upcoming years, due to the increasing aspects of MEMS EH devices in vast applications. In Recent advancements in energy harvesting (EH) technologies wireless sensor devices play a vital role to extend their lifetime readily available in natural resources. In this paper the design of MEMS Cantilever at low frequency (100Hz) with different piezoelectric materials Gallium Arsenide (GaAs), Lead Zirconate Titanate (PZT-8), Tellurium Dioxide (TeO2), Zinc oxide (ZnO) is simulated and performance with different materials are compared. The results are analyzed with various parameters such as electric potential voltage, von mises stress, displacement. The paper discusses the suitability of the piezoelectric material for MEMS fully cochlear implantable sensor application.
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Zheng, Bin, i Liang Ping Luo. "Topology Optimization Design of Implantable Energy Harvesting Device". Applied Mechanics and Materials 55-57 (maj 2011): 498–503. http://dx.doi.org/10.4028/www.scientific.net/amm.55-57.498.
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When designing implantable biomedical MEMS devices, we must provide electric power source with long life and small size to drive the sensors and actuators work. Obviously, traditional battery is not a good choice because of its large size, limited lifetime and finite power storage. Living creatures all have non-electric energy sources, like mechanical energy from heart beat and pulse. Piezoelectric structure can convert mechanical energy to electric energy. In the same design condition, the more electric energy is generated, the better the piezoelectric structure design. This paper discusses the topology optimization method for the most efficient implantable piezoelectric energy harvesting device. Finally, a design example based on the proposed method is given and the result is discussed.
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Zając, Jerzy, Tomasz Gutt, Tomasz Piasecki i Piotr Grabiec. "Selected Questions Related to Characterization of MEMS Structures Comprising PZT Piezo Layer". Journal of Nano Research 39 (luty 2016): 202–13. http://dx.doi.org/10.4028/www.scientific.net/jnanor.39.202.
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PZT (lead zirconium titanate) is an intermetallic compound exhibiting piezoelectric, ferroelectric, and pyroelectric properties. The perovskite crystallographic structure of the PZT is responsible for the above effects. MEMS structures with piezo layers can be used as sensors, actuators, or converters. The abilities of piezo materials to generate an electric charge as a response to stress and a change of shape as a response to electric field are very attractive in numerous applications. Cantilever structures with a mass attached can accordingly be used as energy harvesters converting energy of environment vibrations. Other applications of cantilevers are small displacement sensors or actuators in micro/nanoscale. Membrane structures can work as ultrasonic transducers. If properly shaped cavity is produced, the structure may be used as a part of ink printer head or as a pressure sensor.For physical description of piezo phenomena, constitutive equations in several forms are used. They work well for bulk piezoelectric, although for thin layers deposited on silicon or similar substrate, piezoelectric coupling coefficients must be redefined because of the interaction of thin piezo layer and thicker substrate.Typical electric characterization of piezo MEMS structures includes CV and IV measurements. QV (charge-voltage) hysteresis loop study is an additional method used for this characterization. Complex electromechanical methods are used for surveying piezoelectric coupling coefficients. These methods employ mechanic actuation and electric response Q measurements or AC electric V (voltage) excitation and measurement of mechanical response v (velocity). In the second case, a very precise tool for velocity evaluation is necessary. Such tool could be for example laser Doppler vibrometer, enabling measurements of picometer resolution in several MHz bandwidth. In many cases resonance features of structures have revealed themselves interesting and became a subject of the study. Some vibrometers make measurement of micro cantilever vibrations excited by Brownian movement of air particles possible.
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Wasim, Muhammad Faisal, Shahzadi Tayyaba, Muhammad Waseem Ashraf i Zubair Ahmad. "Modeling and Piezoelectric Analysis of Nano Energy Harvesters". Sensors 20, nr 14 (15.07.2020): 3931. http://dx.doi.org/10.3390/s20143931.
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The expedient way for the development of microelectromechanical systems (MEMS) based devices are based on two key steps. First, perform the simulation for the optimization of various parameters by using different simulation tools that lead to cost reduction. Second, develop the devices with accurate fabrication steps using optimized parameters. Here, authors have performed a piezoelectric analysis of an array of zinc oxide (ZnO) nanostructures that have been created on both sides of aluminum sheets. Various quantities like swerve, stress, strain, electric flux, energy distribution, and electric potential have been studied during the piezo analysis. Then actual controlled growth of ZnO nanorods (NRs) arrays was done on both sides of the etched aluminum rod at low-temperature using the chemical bath deposition (CBD) method for the development of a MEMS energy harvester. Micro creaks on the substrate acted as an alternative to the seed layer. The testing was performed by applying ambient range force on the nanostructure. It was found that the voltage range on topside was 0.59 to 0.62 mV, and the bottom side was 0.52 to 0.55 mV. These kinds of devices are useful in low power micro-devices, nanoelectromechanical systems, and smart wearable systems.
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Matzen, S., S. Gable, N. Lequet, S. Yousfi, K. Rani, T. Maroutian, G. Agnus, H. Bouyanfif i P. Lecoeur. "High piezoelectricity in epitaxial BiFeO3 microcantilevers". Applied Physics Letters 121, nr 14 (3.10.2022): 142901. http://dx.doi.org/10.1063/5.0105404.
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The large switchable ferroelectric polarization and lead-free composition of BiFeO3 make it a promising candidate as an active material in numerous applications, in particular, in micro-electro-mechanical systems (MEMS) when BiFeO3 is integrated in a thin film form on a silicon substrate. Here, 200-nm-thick Mn-doped BiFeO3 thin films have been epitaxially grown on a SrRuO3/SrTiO3/Si substrate and patterned into microcantilevers as prototype device structures for piezoelectric actuation. The devices demonstrate excellent ferroelectric response with a remanent polarization of 55 μC/cm2. The epitaxial BiFeO3 MEMS exhibit very high piezoelectric response with transverse piezoelectric coefficient d31 reaching 83 pm/V. The BiFeO3 cantilevers show larger electromechanical performance (the ratio of curvature/electric field) than that of state-of-art piezoelectric cantilevers, including well-known PZT (Pb(Zr,Ti)O3) and the hyper-active PMN–PT (Pb(Mg1/3Nb2/3)O3-PbTiO3). In addition, the piezoelectricity in BiFeO3 MEMS is found to depend on the ferroelectric polarization direction, which could originate from the flexoelectric effect and be exploited to further enhance the electromechanical performance of the devices. These results could potentially lead to a replacement of lead-based piezoelectrics by BiFeO3 in many microdevices.
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Yan, Zhen, i Qing He. "A Review of Piezoelectric Vibration Generator for Energy Harvesting". Applied Mechanics and Materials 44-47 (grudzień 2010): 2945–49. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.2945.
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Piezoelectric vibration generator has the advantages of small volume and simple technology and working in various poor environments, so it will inevitably power for wireless sensor network, micro electromechanical system (MEMS) devices, and other electric devices, instead of traditional cell. First of all, the generation power principle as well as the vibration mode of piezoelectric vibration generator is presented. Then, the basic theory and its application of structural behavior and damping influence are analyzed. Finally, the problems and the challenge of piezoelectric vibration generator are discussed.
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Ramegowda, Prakasha Chigahalli, Daisuke Ishihara, Tomoya Niho i Tomoyoshi Horie. "Performance Evaluation of Numerical Finite Element Coupled Algorithms for Structure–Electric Interaction Analysis of MEMS Piezoelectric Actuator". International Journal of Computational Methods 16, nr 07 (26.07.2019): 1850106. http://dx.doi.org/10.1142/s0219876218501062.
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This work presents multiphysics numerical analysis of piezoelectric actuators realized using the finite element method (FEM) and their performances to analyze the structure-electric interaction in three-dimensional (3D) piezoelectric continua. Here, we choose the piezoelectric bimorph actuator without the metal shim and with the metal shim as low-frequency problems and a surface acoustic wave device as a high-frequency problem. More attention is given to low-frequency problems because in our application micro air vehicle’s wings are actuated by piezoelectric bimorph actuators at low frequency. We employed the Newmark’s time integration and the central difference time integration to study the dynamic response of piezoelectric actuators. Monolithic coupling, noniterative partitioned coupling and partitioned iterative coupling schemes are presented. In partitioned iterative coupling schemes, the block Jacobi and the block Gauss–Seidel methods are employed. Resonance characteristics are very important in micro-electro-mechanical system (MEMS) applications. Therefore, using our proposed coupled algorithms, the resonance characteristics of bimorph actuator is analyzed. Comparison of the accuracy and computational efficiency of the proposed numerical finite element coupled algorithms have been carried out for 3D structure–electric interaction problems of a piezoelectric actuator. The numerical results obtained by the proposed algorithms are in good agreement with the theoretical solutions.
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Teuschel, Marco, Paul Heyes, Samu Horvath, Christian Novotny i Andrea Rusconi Clerici. "Temperature Stable Piezoelectric Imprint of Epitaxial Grown PZT for Zero-Bias Driving MEMS Actuator Operation". Micromachines 13, nr 10 (10.10.2022): 1705. http://dx.doi.org/10.3390/mi13101705.
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In piezoelectric transducer applications, it is common to use a unipolar operation signal to avoid switching of the polarisation and the resulting nonlinearities of micro-electromechanical systems. However, semi-bipolar or bipolar operation signals have the advantages of less leakage current, lower power consumption and no additional need of a DC−DC converter for low AC driving voltages. This study investigates the potential of using piezoelectric layers with an imprint for stable bipolar operation on the basis of epitaxially grown lead zirconate titanate cantilevers with electrodes made of a metal and metal oxide stack. Due to the manufacturing process, the samples exhibit high crystallinity, rectangular shaped hysteresis and a high piezoelectric response. Furthermore, the piezoelectric layers have an imprint, indicating a strong built-in field, which shifts the polarisation versus electric field hysteresis. To obtain the stability of the imprint, laser doppler vibrometry and switching current measurements were performed at different temperatures, yielding a stable imprinted electric field of −1.83 MV/m up to at least 100 °C. The deflection of the cantilevers was measured with a constant AC driving voltage while varying the DC bias voltage to examine the influence of the imprint under operation, revealing that the same high deflection and low nonlinearities, quantified by the total harmonic distortion, can be maintained down to low bias voltages compared to unipolar operation. These findings demonstrate that a piezoelectric layer with a strong imprint makes it possible to operate with low DC or even zero DC bias, while still providing strong piezoelectric response and linear behaviour.
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Lalas, Antonios X., Nikolaos V. Kantartzis i Theodoros D. Tsiboukis. "Piezoelectrically programmable electric-field driven LC (ELC) resonators acting as THz modulators". COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 35, nr 4 (4.07.2016): 1460–67. http://dx.doi.org/10.1108/compel-12-2015-0480.
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Purpose – Metamaterials are artificially tailored complex media with extraordinary properties, not available in nature. Due to their unique performance, they are considered as a crucial component of modern radio-frequency technology, especially in the THz regime. However, their lack of wide spectral bandwidths introduce constraints for realistic applications. The purpose of this paper is to propose piezoelectric micro-electromechanical systems (MEMS) actuators to modify the shape of electric field-driven LC (ELC) resonators. A THz modulation capability is revealed by connecting/disconnecting the associated metal parts. Design/methodology/approach – Piezoelectric MEMS actuators are proposed to provide the desired bandwidth enhancement along with THz modulation. Two setups with different degrees of freedom in altering the behaviour of the novel modulator are investigated. A variety of numerical data, acquired via the finite element method, substantiate the advantageous characteristics of the proposed structures. Findings – The novel devices enable the modification of the structural features of an ELC-based complex medium, unveiling in this manner a significant THz modulation capability along with improved bandwidth tunability. Two discrete cases are presented involving different degrees of freedom to shape the overall performance of the metamaterial modulator. Originality/value – Development of a THz modulator, which utilises metamaterials as its fundamental component. Incorporation of tunable piezoelectric metamaterials into THz technology allowing increased reconfigurability. Bandwidth enhancement of metamaterial systems and alternative design via multiple controllable gaps enabling more degrees of freedom for design purposes.
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Rizzoni, Raffaella, Michele Serpilli, Maria Letizia Raffa i Frédéric Lebon. "A Micromechanical Model for Damage Evolution in Thin Piezoelectric Films". Coatings 13, nr 1 (3.01.2023): 82. http://dx.doi.org/10.3390/coatings13010082.
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Thin-film piezoelectric materials are advantageous in microelectromechanical systems (MEMS), due to large motion generation, high available energy and low power requirements. In this kind of application, thin piezoelectric films are subject to mechanical and electric cyclic loading, during which damage can accumulate and eventually lead to fracture. In the present study, continuum damage mechanics and asymptotic theory are adopted to model damage evolution in piezoelectric thin films. Our purpose is to develop a new interface model for thin piezoelectric films accounting for micro-cracking damage of the material. The methods used are matched asymptotic expansions, to develop an interface law, and the classic thermodynamic framework of continuum damage mechanics combined with Kachanov and Sevostianov’s theory of homogenization of micro-cracked media, to characterize the damaging behavior of the interface. The main finding of the paper is a soft imperfect interface model able to simulate the elastic and piezoelectric behavior of thin piezoelectric film in the presence of micro-cracking and damage evolution. The obtained interface model is expected to be a useful tool for damage evaluation in MEMS applications. As an example, an electromechanically active stack incorporating a damaging piezoelectric layer is studied. The numerical results indicate a non-linear evolution of the macroscopic response and a damage accumulation qualitatively consistent with experimental observations.
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Liu, Zhirong, Min Zhu, Caihua Xu, Wenqi Bao, Liqiang Xie, Haitao Zhang i Yueqi Han. "Electric field sensing characteristics of ZnO/SiO2/Si surface acoustic wave devices". Journal of Micromechanics and Microengineering 32, nr 5 (17.03.2022): 055001. http://dx.doi.org/10.1088/1361-6439/ac5b1c.
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Abstract Existing microelectro mechanical systems (MEMSs) electric field sensors have movable parts and electronic components. The movable parts are susceptible to external vibration, and the electronic components distort the distribution of the measured electric field. Therefore, we proposed a novel MEMS electric field sensor based on surface acoustic wave (SAW) technology. The SAW electric field sensor is a delay line device with an interdigital transducer and a reflector. The substrate of the device is a ZnO/SiO2/Si multilayer structure. The ZnO piezoelectric layer is not only used as the propagation medium of SAW, but also used as the sensing film of the external electric field. Then, the external electric field could be detected by analyzing the change of the eigenfrequency of the SAW. The multilayer structure of the substrate was prepared by MEMS process. The interdigital transducer and the reflector are fabricated by the lift-off process. The SAW sensor is characterized at different external electric field strengths by a network analyzer. The sensitivity of the sensor was 0.23 kHz/(kV m−1) and the nonlinearity was 6.8%.
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Buynosov, Alexander Petrovich, Vitaliy Albertovich Vasilyev, Alexey Viktorovich Erpalov, Anton Yuryevich Nitskiy i Alexander Sergeevich Baitov. "Analysis of electric noise at vibration based diagnostics of motor-coach stock assemblies". Transport of the Urals, nr 2 (2020): 10–15. http://dx.doi.org/10.20291/1815-9400-2020-2-10-15.
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Wide dynamic and frequency ranges, low level of noise allow using piezoelectric accelerometers as general purpose sensors for monitoring and diagnostics of vibration condition of assemblies of prospective motivecoach stock. Electric noise of a vibration parameters measuring channel depends not only on noise from the detecting element, but also on the further processing of a signal, first of all on the operation of an analog-todigital converter (ADC). The paper considers a comparative analysis of electric noise level of the vibration parameters measuring channel for piezoelectric and MEMS-accelerometers with the consideration for the influence of the ADC. As a result, the best ADCs for measuring vibration parameters are 12-digit and 16-digit ones.
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Javed, Yaser, Mohtashim Mansoor i Irtiza Ali Shah. "A review of principles of MEMS pressure sensing with its aerospace applications". Sensor Review 39, nr 5 (16.09.2019): 652–64. http://dx.doi.org/10.1108/sr-06-2018-0135.
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Purpose Pressure, being one of the key variables investigated in scientific and engineering research, requires critical and accurate measurement techniques. With the advancements in materials and machining technologies, there is a large leap in the measurement techniques including the development of micro electromechanical systems (MEMS) sensors. These sensors are one to two orders smaller in magnitude than traditional sensors and combine electrical and mechanical components that are fabricated using integrated circuit batch-processing technologies. MEMS are finding enormous applications in many industrial fields ranging from medical to automotive, communication to electronics, chemical to aviation and many more with a potential market of billions of dollars. MEMS pressure sensors are now widely used devices owing to their intrinsic properties of small size, light weight, low cost, ease of batch fabrication and integration with an electronic circuit. This paper aims to identify and analyze the common pressure sensing techniques and discuss their uses and advantages. As per our understanding, usage of MEMS pressure sensors in the aerospace industry is quite limited due to cost constraints and indirect measurement approaches owing to the inability to locate sensors in harsh environments. The purpose of this study is to summarize the published literature for application of MEMS pressure sensors in the said field. Five broad application areas have been investigated including: propulsion/turbomachinery applications, turbulent flow diagnosis, experimentalaerodynamics, micro-flow control and unmanned aerial vehicle (UAV)/micro aerial vehicle (MAV) applications. Design/methodology/approach The first part of the paper deals with an introduction to MEMS pressure sensors and mathematical relations for its fabrication. The second part covers pressure sensing principles followed by the application of MEMS pressure sensors in five major fields of aerospace industry. Findings In this paper, various pressure sensing principles in MEMS and applications of MEMS technology in the aerospace industry have been reviewed. Five application fields have been investigated including: Propulsion/Turbomachinery applications, turbulent flow diagnosis, experimental aerodynamics, micro-flow control and UAV/MAV applications. Applications of MEMS sensors in the aerospace industry are quite limited due to requirements of very high accuracy, high reliability and harsh environment survivability. However, the potential for growth of this technology is foreseen due to inherent features of MEMS sensors’ being light weight, low cost, ease of batch fabrication and capability of integration with electric circuits. All these advantages are very relevant to the aerospace industry. This work is an endeavor to present a comprehensive review of such MEMS pressure sensors, which are used in the aerospace industry and have been reported in recent literature. Originality/value As per the author’s understanding, usage of MEMS pressure sensors in the aerospace industry is quite limited due to cost constraints and indirect measurement approaches owing to the inability to locate sensors in harsh environments. Present work is a prime effort in summarizing the published literature for application of MEMS pressure sensors in the said field. Five broad application areas have been investigated including: propulsion/turbomachinery applications, turbulent flow diagnosis, experimental aerodynamics, micro-flow control and UAV/MAV applications.
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Liang, Yen-Chu, Yun-Ping Sun i Lung-Nan Wu. "HOLE PROBLEMS IN A CIRCULAR PIEZOELECTRIC PLATE". Transactions of the Canadian Society for Mechanical Engineering 40, nr 4 (listopad 2016): 491–500. http://dx.doi.org/10.1139/tcsme-2016-0037.
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Due to the unique electric-mechanical coupling effects, piezoelectric materials are widely used in sensors and actuators. Not only in smart structures but also in structural health monitoring, the developments of piezoelectric materials combined with the micro electro mechanical system (MEMS) techniques make our lives totally different. This paper provides a series of numerical simulations about the circular piezoelectric plate with a hole in the plate by using the special boundary element method (BEM). The Green’s functions of BEM are obtained from the derivation of extended Stroh formalism. By this formalism, the analytical closedform solutions of hole in an infinite piezoelectric medium under various loading conditions are obtained. The results demonstrate the coupling effects with different boundary conditions in the circular plate, which will satisfy the requirements of the designers who need to use the products with the hole in the piezoelectric circular plate.
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Jin, Lei, Shiqiao Gao, Xiyang Zhang i Qinghe Wu. "Output of MEMS Piezoelectric Energy Harvester of Double-Clamped Beams with Different Width Shapes". Materials 13, nr 10 (19.05.2020): 2330. http://dx.doi.org/10.3390/ma13102330.
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For a microelectromechanical system (MEMS) piezoelectric energy harvester consisting of double-clamped beams, the effects of both beam shape and electrode arrangement on the voltage outputs are analyzed. For two kinds of harvester structures including millimeter-scale and micro-scale, and different shapes including rectangular, segmentally trapezoidal and concave parabolic are taken into account. Corresponding electric outputs are calculated and tested. Their results are in good agreement with each other. The experimental results validate the theoretical analysis.
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Li, Xingjia, i Ying Luo. "Flexoelectric Effect on Vibration of Piezoelectric Microbeams Based on a Modified Couple Stress Theory". Shock and Vibration 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/4157085.
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A novel electric Gibbs function was proposed for the piezoelectric microbeams (PMBs) by employing a modified couple stress theory. Based on the new Gibbs function and the Euler-Bernoulli beam theory, the governing equations which incorporate the effects of couple stress, flexoelectricity, and piezoelectricity were derived for the mechanics of PMBs. The analysis of the effective bending rigidity shows the effects of size and flexoelectricity can greaten the stiffness of PMBs so that the natural frequency increases significantly compared with the Euler-Bernoulli beam, and then the mechanical and electrical properties of PMBs are enhanced compared to the classical beam. This study can guide the design of microscale piezoelectric/flexoelectric structures which may find potential applications in the microelectromechanical systems (MEMS).
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KURIBAYASHI, Hideyuki, Hwisim HWAMG, Yusuke MORITA i Eiji NAKAMACHI. "520 Development of Electric Power Supply System for Bio-MEMS by UsingNew Bio-compatible Piezoelectric Material MgSiO3". Proceedings of Conference of Kansai Branch 2011.86 (2011): _5–20_. http://dx.doi.org/10.1299/jsmekansai.2011.86._5-20_.
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Xue, Fen, Jun Hu, Yue Guo, Guowei Han, Yong Ouyang, Shan X. Wang i Jinliang He. "Piezoelectric–Piezoresistive Coupling MEMS Sensors for Measurement of Electric Fields of Broad Bandwidth and Large Dynamic Range". IEEE Transactions on Industrial Electronics 67, nr 1 (styczeń 2020): 551–59. http://dx.doi.org/10.1109/tie.2019.2893837.
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Araujo, Luis Antonio Oliveira, J. M. D. A. Rollo, C. R. Foschini i Carlos Alberto Fortulan. "Study of Abrasive Cutting of Natural Quartz for Manufacturing Piezoelectric Power Generators". Materials Science Forum 912 (styczeń 2018): 234–39. http://dx.doi.org/10.4028/www.scientific.net/msf.912.234.
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The present study is related with the dicing of natural quartz crystals as part of the process manufacturing of a power generator device. Power generation is important, mainly for wifi systems, which use of batteries is restrictive or impossible due short dimensions and difficult of maintenance. The manufacturing dicing process applied in micro electromechanical systems (MEMS) is the main reference for this study, which objective is explores different parameters of dicing process and the impact of it in the final performance of the generator. Failure impregnation and productivity were study in blade and band saw process with different parameters as speed and cutting force. The natural quartz was selected mainly because availability in Brazil and piezoelectric properties. It was obtained substrates AT cutting plan with thickness of 2.5mm and width of 3mm. The material was tested under compressive stress and the correspondent electric signal was obtained.
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Cohen, Asaf, Hagai Cohen, Sidney R. Cohen, Sergey Khodorov, Yishay Feldman, Anna Kossoy, Ifat Kaplan-Ashiri i in. "C-Axis Textured, 2–3 μm Thick Al0.75Sc0.25N Films Grown on Chemically Formed TiN/Ti Seeding Layers for MEMS Applications". Sensors 22, nr 18 (17.09.2022): 7041. http://dx.doi.org/10.3390/s22187041.
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A protocol for successfully depositing [001] textured, 2–3 µm thick films of Al0.75Sc0.25N, is proposed. The procedure relies on the fact that sputtered Ti is [001]-textured α-phase (hcp). Diffusion of nitrogen ions into the α-Ti film during reactive sputtering of Al0.75,Sc0.25N likely forms a [111]-oriented TiN intermediate layer. The lattice mismatch of this very thin film with Al0.75Sc0.25N is ~3.7%, providing excellent conditions for epitaxial growth. In contrast to earlier reports, the Al0.75Sc0.25N films prepared in the current study are Al-terminated. Low growth stress (<100 MPa) allows films up to 3 µm thick to be deposited without loss of orientation or decrease in piezoelectric coefficient. An advantage of the proposed technique is that it is compatible with a variety of substrates commonly used for actuators or MEMS, as demonstrated here for both Si wafers and D263 borosilicate glass. Additionally, thicker films can potentially lead to increased piezoelectric stress/strain by supporting application of higher voltage, but without increase in the magnitude of the electric field.
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Bilgen, Onur, Lauren M. Butt, Steven R. Day, Craig A. Sossi, Joseph P. Weaver, Artur Wolek, William H. Mason i Daniel J. Inman. "A novel unmanned aircraft with solid-state control surfaces: Analysis and flight demonstration". Journal of Intelligent Material Systems and Structures 24, nr 2 (23.09.2012): 147–67. http://dx.doi.org/10.1177/1045389x12459592.
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This article presents a completely servo-less, piezoelectric controlled, wind tunnel and flight tested, remotely piloted aircraft that has been developed by the 2010 Virginia Tech Wing Morphing Design Team (a senior design project between the Departments of Mechanical Engineering and Aerospace and Ocean Engineering). A type of piezocomposite actuator, the Macro-Fiber Composite, is used for changing the camber of all control surfaces on the aircraft. The aircraft is analyzed theoretically for its aerodynamic characteristics to aid the design of the piezoelectric control surfaces. A vortex lattice analysis complemented the database of aerodynamic derivatives used to analyze control response. Steady-state roll rates were measured in a wind tunnel and were compared to a similar aircraft with servomotor actuated control surfaces. The theoretical analysis and wind tunnel testing demonstrated the stability and control authority of the concept, culminating in the first flight of the completely Macro-Fiber Composite controlled aircraft on 29 April 2010. An electric motor-driven propulsion system is used to generate thrust, and all systems are powered with a single lithium polymer battery. This vehicle became the first completely Macro-Fiber Composite controlled, flight tested aircraft. It is also known to be the first fully solid-state piezoelectric material controlled, nontethered, flight tested fixed-wing aircraft.
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Kranz, Michael, Mark Allen i Tracy Hudson. "In-Situ Wafer-Level Polarization of Electret Films in MEMS Acoustic Sensor Arrays". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, DPC (1.01.2011): 001732–60. http://dx.doi.org/10.4071/2011dpc-wp24.
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MEMS-based electret and polymer piezoelectric transduction techniques have been reported for both acoustic sensors and energy harvesters. Common techniques employed in MEMS polymer polarization include corona discharge and backlighted thyratron. This paper reports a method for post-fabrication in-situ polarization of polymer films embedded within the MEMS device itself. The method utilizes microplasma discharges with self-aligned charging grids integrated within the device to charge fluoropolymer films in a fashion similar to the common corona discharge technique. This in-situ approach enables the integration of uncharged polymer films into MEMS and subsequent post-fabrication and post-packaging polarization, simultaneously enabling the formation of buried or encapsulated electrets as well as eliminating the need to restrict fabrication and packaging processes that might otherwise discharge pre-charged materials. CYTOP, a thermoplastic fluoropolymer encapsulant for electronics, is used as a polymer electret in the current process because it can be spin-cast, has a high resistivity, and is easily etched in oxygen plasma. A microscale charging grid structure is then fabricated and suspended a short distance above the polymer film. After fabrication of the charging grid, standard microfabrication steps are performed to build a single-chip array of MEMS capacitive acoustic sensors designed to capture and analyze waveforms from impacts. After completing the entire fabrication and packaging flow, the polarization process is performed. When energized by a high voltage, the sharp metal edges of the charging grid lead to high dielectric fields that ionize the air in the gap and force electric charge onto the polymer surface. Final sensor arrays have been demonstrated and applied in the classification of acoustic stress pulses generated during impacts of various materials.
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Choudhary, Nitin, D. K. Kharat i Davinder Kaur. "Improved Electrical and Mechanical Properties of Niti/TiOx/PZT/TiOx Thin Film Heterostructures". Solid State Phenomena 185 (luty 2012): 25–27. http://dx.doi.org/10.4028/www.scientific.net/ssp.185.25.
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Nickel-titanium (NiTi) alloys are high-performance shape memory alloy actuator materials [1]. These alloys are metals possessing a memory, which can be triggered thermally or mechanically. Thin film of nickel-titanium shape memory alloy (SMA) is an excellent candidate for micro electric mechanical systems (MEMS). On the other hand, PZT is well known for its superior ferroelectric, dielectric and piezoelectric properties [2]. Integrating a ferroelectric (PZT) with ferroelastic (NiTi) material is technically interesting as the resulting heterostructure may then produce the properties associated with both of the materials and enhances the performance of MEMS based devices [3]. An important issue in the synthesis of NiTi/PZT hybrid heterostructure is the formation of appropriate crystalline phases of each material. The interdiffusions present at the interface of NiTi and PZT layer makes it difficult to obtain the optimal properties of both the components suitably at lower thickness values. With the miniaturization of active thin film devices, particularly for MEMS applications, it is desirable to obtain the best properties at lower thickness values. Therefore, in the present study, we have tried to lower the thickness of top NiTi films with the help of thin TiOx buffer layer between PZT and NiTi films. As expected, the excellent structural, electrical and mechanical properties of the NiTi/PZT heterostructure were achieved at lower thickness values.
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Lee, Young Sup, Hyoung Jin Im, Jaehwa Kwon i Dong Jin Yoon. "Biologically Inspired Smart Sensor for Acoustic Emission Detection". Key Engineering Materials 321-323 (październik 2006): 204–7. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.204.
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This paper presents concept, analysis and experiment of a novel sensor which is based on biologically inspired approach for acoustic emission (AE) detection. It is known that a conventional AE sensor consists of a matching layer, piezoelectric transducer, backing layer, supporting electric circuit and casing. The conventional AE sensors have been widely used to detect defects in various structures and they have designed as either broadband or resonant type. However, the novel sensor described in this paper utilizes the concept of hearing organs in animals with the help of micro electro-mechanical systems (MEMS) technology. The basic design with theoretical investigation including finite element analysis showed the core hearing element such as a hair cell could be implemented with the piezoeletric material. Also it is found that the dimensional variety and proper distribution of such elements inside the sensor are critical parameters to the detectability of AE signals from structures. Both the broadband and resonant type AE sensors with relevant electric circuits could be implemented with this novel sensor concept.
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Strnad, Nicholas A., Wendy L. Sarney, Gilbert B. Rayner, Robert R. Benoit, Glen R. Fox, Ryan Q. Rudy, Thomas J. Larrabee, Jeffrey Shallenberger i Jeffrey S. Pulskamp. "Plasma enhanced atomic layer deposition of textured aluminum nitride on platinized substrates for MEMS". Journal of Vacuum Science & Technology A 40, nr 4 (lipiec 2022): 042403. http://dx.doi.org/10.1116/6.0001633.
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We demonstrate an N2 plasma-enhanced process for inducing (0001)-oriented ALD-grown AlN on planar substrates. We evaluate the impact of {111}-textured Pt as a growth template, precursor chemistry, dose time, stress-engineered substrates, inductively coupled plasma conditions for film bombardment during growth, and ALD equipment configurations. The thin film transverse piezoelectric coefficient e31,f determined from measurements on microelectromechanical system cantilevers coated by PEALD AlN is reported to be −0.53 ± 0.03 C/m2. An analysis of the Pt-AlN interface properties based primarily on depth-profile x-ray photoemission spectroscopy and transmission electron microscopy-energy dispersive spectra is presented. Other than the c axis wurtzite (0001) diffraction peak, no other AlN peaks were observed above the detection limits for XRD measurements. The XRD rocking-curve full-width half-maximum of the 0001 peaks was 2.9° omega, which was achieved on {111}-textured Pt. The relative dielectric constant was measured to be 8.1 < K < 8.6, and an average dielectric loss of < 0.01 was observed within the applied electric field range of ±3350 kV/cm at 10 kHz. The leakage current of the textured AlN was quite low at 1.5 × 10−6 A/cm2 over the applied field range of ±1820 kV/cm.
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Wang, Chen, Yang Yang, Lifeng Qin, Shenglin Ma i Yufeng Jin. "A Strategy for Extracting Full Material Coefficients of AlN Thin Film Based on Resonance Method". Micromachines 13, nr 4 (25.03.2022): 513. http://dx.doi.org/10.3390/mi13040513.
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AlN thin film is widely used in piezoelectric MEMS devices, and the accurate characterizations of its material coefficients are critical for the optimization of the AlN thin film process and the design of AlN thin-film-based devices. However, it is difficult to extract the material coefficients of AlN in the form of thin film. This paper reports a strategy for systematically extracting full elastic coefficients, piezoelectric coefficients and dielectric constants of c-axis-oriented AlN thin film based on the resonance method outlined in IEEE Standard on Piezoelectricity Std 176-1987. In this strategy, four self-suspended resonators with length thickness extension (LTE), thickness extension (TE), radial extension (RE), lateral electric field excited thickness shear (LEF-TS) modes together with a lamb wave resonator (LWR) are specifically adopted, and the material coefficients of AlN thin film are extracted by measuring the impedance spectra of these resonators. In addition, the effects of the pad and electrodes on the resonators were systematically studied, and the corresponding procedures to eliminate their influences on the extraction accuracy of material coefficients were proposed. Finally, a complete extraction process based on the above strategy was established. The simulation results show that the strategy can achieve high accuracy for AlN thin film with different thicknesses and electrode configurations, and it can also be applied to other materials belonging to the 6 mm piezoelectric crystal class such as ZnO, ScAlN, etc.
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Wang, Dong F., Kohei Isagawa, Takeshi Kobayashi, Toshihiro Itoh i Ryutaro Maeda. "Passive piezoelectric single-side MEMS DC current sensor with five parallel PZT plates applicable to two-wire DC electric appliances without using cord separator". Microsystem Technologies 19, nr 6 (21.02.2013): 923–27. http://dx.doi.org/10.1007/s00542-013-1749-4.
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Ji, X., i A. Q. Li. "The Size-Dependent Electromechanical Coupling Response in Circular Micro-Plate due to Flexoelectricity". Journal of Mechanics 33, nr 6 (17.10.2016): 873–83. http://dx.doi.org/10.1017/jmech.2016.104.
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AbstractFlexoelectricity, the coupling of strain gradient to polarization, enhances the properties of piezoelectric response desirable for advanced MEMS dramatically even in centrosymmetric dielectrics. In this paper, the general formulations of the flexoelectric couple stress theory presented by Hadjesfandiari in orthogonal curvilinear coordinate system are derived, and are then specified for the case of cylindrical coordinates. A size-dependent flexoelectric model of circular plate is established based on the current formulations in cylindrical coordinates. The governing equations, boundary conditions and initial conditions are derived by applying Hamilton's principle. The static bending and free vibration problems of a simply supported axisymmetric circular plate are carried out to illustrate the applicability of the present model. Numerical results reveal that a homogeneous electric field between the up and down surfaces of the circular plate is induced indeed. The generated deflection, induced voltage and natural frequency show obvious size effect, but the size effect is almost diminishing as the thickness of the plate is far greater than the material length scale parameter. As the increase of the flexoelectric coefficient, the induced voltage increases evidently and the generated deflection and the natural frequency increase weakly.
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Zamora, Iván, Eyglis Ledesma, Arantxa Uranga i Núria Barniol. "Miniaturized 0.13-μm CMOS Front-End Analog for AlN PMUT Arrays". Sensors 20, nr 4 (22.02.2020): 1205. http://dx.doi.org/10.3390/s20041205.
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This paper presents an analog front-end transceiver for an ultrasound imaging system based on a high-voltage (HV) transmitter, a low-noise front-end amplifier (RX), and a complementary-metal-oxide-semiconductor, aluminum nitride, piezoelectric micromachined ultrasonic transducer (CMOS-AlN-PMUT). The system was designed using the 0.13-μm Silterra CMOS process and the MEMS-on-CMOS platform, which allowed for the implementation of an AlN PMUT on top of the CMOS-integrated circuit. The HV transmitter drives a column of six 80-μm-square PMUTs excited with 32 V in order to generate enough acoustic pressure at a 2.1-mm axial distance. On the reception side, another six 80-μm-square PMUT columns convert the received echo into an electric charge that is amplified by the receiver front-end amplifier. A comparative analysis between a voltage front-end amplifier (VA) based on capacitive integration and a charge-sensitive front-end amplifier (CSA) is presented. Electrical and acoustic experiments successfully demonstrated the functionality of the designed low-power analog front-end circuitry, which outperformed a state-of-the art front-end application-specific integrated circuit (ASIC) in terms of power consumption, noise performance, and area.
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Zhang, Tao, Hailong Li, Chenlei Zhou, Huaze Zhu, Yahong Zhou, Fujun Liang, Huafeng Pang, Limei Hao i Shaorong Li. "Ferroelectricity, Piezoelectricity, and Dielectricity of 0.06PMnN-0.94PZT(45/55) Thin Film on Silicon Substrate". Journal of Nanomaterials 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/864591.
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The high piezoelectricity and high quality factor ferroelectric thin films are important for electromechanical applications especially the micro electromechanical system (MEMS). The ternary compound ferroelectric thin films 0.06Pb(Mn1/3, Nb2/3)O3+ 0.94Pb(Zr0.45, Ti0.55)O3(0.06PMnN-0.94PZT(45/55)) were deposited on silicon(100) substrates by RF magnetron sputtering method considering that Mn and Nb doping will improve PZT properties in this research. For comparison, nondoped PZT(45/55) films were also deposited. The results show that both of thin films show polycrystal structures with the main (111) and (101) orientations. The transverse piezoelectric coefficients aree31,eff=−4.03 C/m2ande31,eff=-3.5 C/m2, respectively. These thin films exhibit classical ferroelectricity, in which the coercive electric field intensities are2Ec=147.31 kV/cm and2Ec=135.44 kV/cm, and the saturation polarizationPs=30.86 μC/cm2andPs=17.74 μC/cm2, and the remnant polarizationPr=20.44 μC/cm2andPr=9.87 μC/cm2, respectively. Moreover, the dielectric constants and loss areεr=681andD=5% andεr=537andD=4.3%, respectively. In conclusion, 0.06PMnN-0.94PZT(45/55) thin films act better than nondoped films, even though their dielectric constants are higher. Their excellent ferroelectricity, piezoelectricity, and high power and energy storage property, especially the easy fabrication, integration realizable, and potentially high quality factor, make this kind of thin films available for the realistic applications.
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Lee, Sung Q., Hye Jin Kim, Sang Kyun Lee, Jae Woo Lee i Kang Ho Park. "PMN-PT Single Crystal Piezo-Electric Acoustic Sensor". MRS Proceedings 1034 (2007). http://dx.doi.org/10.1557/proc-1034-k03-46.
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AbstractThe MEMS (micro-electro-mechanical systems) microphone enables the manufacturing of small mechanical components on the surface of a silicon wafer. The MEMS microphones are less susceptible to vibration because of the smaller diaphragm mass and an excellent candidate for chip-scale packaging. In this paper, we present a piezoelectric MEMS microphone based on (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) single crystal diaphragm. The PMN-PT materials exhibit extremely high piezoelectric coefficients and other desirable properties for an acoustic sensor. The piezoelectric-based microphone can offer the ability to passively sense without the power requirements. In particular, this paper introduces the design of a PMN-PT single crystal diaphragm with interdigitated electrode. We were able to fabricate miniaturized PMN-PT single crystal diaphragms. The fabricated sensor exhibits the sensitivity of 1.5mV/Pa. This implies that the PMN-PT thin film microphone has a potential of excellent acoustic characteristics.
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Liu, Guote, Yuanhao Ye, Bing Luo, Yu Gu, Weijia Zheng i Sijun Chen. "Structural optimization and simulation of piezoelectric- piezoresistive coupled MEMS steady-state electric field sensor". Frontiers in Energy Research 10 (13.01.2023). http://dx.doi.org/10.3389/fenrg.2022.1006777.
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Abstract: In view of the problems of large volume, high energy consumption and difficult maintenance of electric field measurement sensors in existing power systems, non-contact miniature electric field sensors have become a hot topic in current research. In this paper, a MEMS miniature electric field measurement sensor model based on the principle of piezoelectric-piezoresistive coupling is constructed, and the sensor structure is optimized by analyzing the steady-state characteristics of the piezoelectric material and semiconductor membrane of the sensor. The input and output characteristics of the sensor were tested. The test results show that the sensor has excellent mechanical strain capacity, and the output voltage of the sensor has a linear relationship with the electric field strength, thus verifying the feasibility of the sensor measurement in the electric field. The research results will provide some reference for the development of contactless coupled sensors.
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Shindo, Yasuhide, Fumio Narita i Koji Sato. "Dynamic Electromechanical Field Concentrations Near Electrodes in Piezoelectric Thick Films for the Design of MEMS Mirrors". Journal of Mechanical Design 134, nr 5 (25.04.2012). http://dx.doi.org/10.1115/1.4006265.
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This paper studies the dynamic electromechanical response of piezoelectric mirrors driven by piezoelectric lead zirconate titanate (PZT) thick films both numerically and experimentally. The resonant frequency and the mirror tilt angle of piezoelectric mirrors under ac electric fields were analyzed by three-dimensional finite element method. The dynamic electromechanical field concentrations due to electrodes were also simulated and the results were discussed in detail. The mirrors consisted of four partially poled PZT unimorphs. The resonant frequency was then measured, and a comparison was made between the analysis and the experiment. The finite element method is shown to be capable of estimating the electromechanical field concentrations in the PZT films, making it a useful tool for designing future microelectromechanical systems (MEMS) mirrors.
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Pagán, V. R., i D. Korakakis. "Finite Element Analysis of Aluminum Nitride Bimorph Actuators – The Influence of Contact Geometry and Position". MRS Proceedings 1129 (2008). http://dx.doi.org/10.1557/proc-1129-v11-01.
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AbstractIn this work, the results of 3-dimensional finite element analysis (FEA) of Aluminum Nitride (AlN) homogeneous bimorphs (d31 mode) are shown. The coupled-field FEA simulations were performed using the commercially available software tool ANSYS. The effect of altering the contact geometry and position on the displacement, electric field, stress, and strain distributions for the static case is reported.Piezoelectric beams are commonly used in microelectromechanical systems (MEMS) and also have many possible applications in smart sensor and actuator systems. For example, they have been used as the active element in microfluidic and microactuator MEMS devices. In the actuator mode, they employ the converse piezoelectric effect to couple electrical energy into mechanical deformation. Aluminum Nitride (AlN) based devices have attracted much interest because AlN is a piezoelectric material with high thermal stability, high dielectric strength, a reasonable electromechanical coupling coefficient, and a perfect compatibility with standard silicon processing techniques.
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Kholkin, A. L., I. K. Bdikin, V. V. Shvartsman, A. Orlova, D. Kiselev, A. A. Bogomolov i S. H. Kim. "Local electromechanical properties of ferroelectric materials for piezoelectric applications". MRS Proceedings 838 (2004). http://dx.doi.org/10.1557/proc-838-o7.6.
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ABSTRACTLocal electromechanical characterization is becoming prerequisite for the development of ferroelectric-based piezoelectric devices including multilayer actuators, micromotors, piezoelectric filters and, especially, microelectromechanical systems (MEMS), which combine piezoelectric elements and control electronics on the same chip. In this work, we present the results of local electromechanical characterization of several important ferroelectric materials including Pb(Zr, Ti)O3 (PZT) and (Pb, La)(Zr, Ti)O3 (PLZT) in both thin film and ceramic form. Local piezoelectric hysteresis measurements are performed by the piezoelectric force microscopy (PFM) that detects small electric field-induced deformation on the nanoscale e. g., within the single grain of a polycrystalline material. A number of novel phenomena is observed with increasing dc bias voltage including the jump of ferroelectric domain wall to the grain boundary, the “fingerlike” instability of domain wall, and the local phase transition into ferroelectric phase.
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Shen, Dongna, Song-Yul Choe i Dong-Joo Kim. "Comparison of Piezoelectric Materials for Vibration Energy Conversion Devices". MRS Proceedings 966 (2006). http://dx.doi.org/10.1557/proc-0966-t07-34.
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ABSTRACTPiezoelectric materials have been investigated as vibration energy converters to power wireless devices or MEMS devices due to recent low power requirement of such devices and the development of miniaturization technology. It has shown the potential that piezoelectric power generator can be an alternative to the traditional power source-battery because of facile vibration sources in our environment and the potential elimination of maintenance required for large volume batteries. To date, PZT (Lead Zirconium Titanate) has been commonly exploited as a piezoelectric material for energy conversion since it can generate higher power density even at low-g (< 1 g) vibration environment. Its high fragility, however, can limit its applicability at high-g conditions. Therefore, other types of piezoelectric materials such as polymer and composite are necessary to investigate the applicability at severe vibration conditions. In this study, piezoelectric power generators based on cantilever beam structure were designed, optimized, and fabricated by considering matching the resonant frequency with environmental vibration, achieving maximum output power, and reaching maximum g-value without device failure. As piezoelectric materials, ceramic PZT, polymer PVDF (Polyvinylidene fluoride) and composite MFC (Macro Fiber Composite) were utilized. The energy conversion of all three types of generator devices was systematically evaluated. All three devices were measured to generate enough power density for providing electric energy to wireless sensor or MEMS device. The PZT device shows the highest output energy density and PVDF device has the highest durability to operate at high-g vibration condition.
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Jean-Mistral, Claire, Louis Carlioz, Maxime Defosseux, Marcin Marzencki, Orphèe Cugat, Jèrôme Delamare i Skandar Basrour. "Thermo-Magnetic, Piezo-Electric and Electroactive Energy Harvesting Devices". MRS Proceedings 1218 (2009). http://dx.doi.org/10.1557/proc-1218-z04-03.
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AbstractWe present three approaches to harvesting ambient energy, based on complementary physical effects in order to exploit three kinds of energy available for harvesting:Mechanical vibrationsMechanical vibration energy can be harvested with resonant mechanical structures excited by the vibrations; this scavenged energy is then transformed into electricity by piezoelectric materials. We propose to use thin piezoelectric layers deposited on the resonant structure.An on-chip integrated prototype, using a seismic mass at the end of a Si cantilever beam coated with a piezoelectric AlN film (overall volume 5 mm3), produces 30 nW of rectified power at 3 V under 0.4 g acceleration, which is enough to power a wireless sensor. Power conditioning electronics adapted to ultra-low voltage input is also proposed, which can efficiently charge a storage capacitor under very low accelerations. The fully micro-fabricated System on a Package combines a MEMS generator and ASIC power management circuit.Evolutions of ambient temperatureA permanent magnet is attached to a PZT/brass bimorph, and placed near a "thermo-magnetic" material (FeNi) which Curie temperature can be tuned around the ambient. During slow cooling or heating by the ambient air, the FeNi magnetic properties vary slowly and thus the attraction force between the FeNi and the NdFeB magnet varies slowly. Despite the slow global evolutions, the opposition between the linearity of the bimorph bending and the strong non-linearity of the magnetic attraction over distance leads to brutal clamping or release of the magnet around Tc: the piezo can then efficiently convert these fast deformations into electricity. Operational temperature range can be set by tuning the FeNi composition to obtain a predefined Curie point; hysteresis between the cooling/heating thresholds can be tuned by modifying the gap between the magnet and the FeNi.The cm-scale prototype generates a peak voltage of 35 V on release (T > Tc). For a discharge time of 0.1 s through a 1 MΩ load, the total energy harvested is 13.5 μJ per stroke, i.e. 1.35 mW of average power (respectively -14 V, 2.2 μJ and 0.22 mW on clamping when T < Tc). Output power is surprisingly constant for various load values tested. Scaling effects must now be addressed to assess the feasibility of an integrated MEMS generator and its potential efficiency.Low-frequency, large amplitude bending from human motion:A very light, flexible electro-active polymer membrane (50 x 30 mm, 31 μm thick) operates in a large frequency spectrum from quasi-static to dynamic range. It scavenges 0.1 mJ per cycle at 1 Hz, under 170 V and constant charge Q: 100 μW is enough to supply a low-power system.Improvements under investigation include achieving poling voltage with piezoelectric polymer or electrets polymer, using multi-stack scavengers to miniaturize the structure and to decrease the poling voltage V, and integration into textile.
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Glumac, D. E., T. G. Cooney, L. F. Francis i W. P. Robbins. "A Theoretical Examination of Mems Microactuator Responses with an Emphasis on Materials and Fabrication". MRS Proceedings 360 (1994). http://dx.doi.org/10.1557/proc-360-407.
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AbstractA free standing cantilever beam consisting of a support structural material (polysilicon/silicon nitride), a piezoelectric PZT ceramic layer, and metal electrode layers has been analyzed. Beam theory and finite element analysis were used to model the electric field induced deflections of this structure, and provided information as to how material choices influenced actuator function. Both support material and PZT thicknesses varied from 0-1.0 gim, and bulk piezoelectric coefficients and elastic moduli were assumed. The beam theory uses known (or assumed) material properties to predict actuator responses. Conversely, if device responses can be measured, material properties may be inferred from the theory. For a PZT thickness of 0.3 μm, a core layer thickness of 0.13 μm was found to maximize displacement. Also, the force output was found to be more dependent on the core thickness than that of the PZT. This information can then be used to predict the response of a more complex microactuator.
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Meena, D., P. Jegan, R. Puviyarasan i R. Sathish. "Design of Piezoelectric Energy Harvester and Power Conditioning". International Journal of Scientific Research in Science, Engineering and Technology, 8.04.2020, 519–26. http://dx.doi.org/10.32628/ijsrset2072102.
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The existing system presents a novel approach called simultaneous wireless strain sensing and energy harvesting from multiple piezo-patches, which is intended for self-powered Structural Health Monitoring applications. The Energy Harvesting subsystem is mainly the self-powered extended synchronous electric charge extraction interface based on double cross-coupled rectifying structure and a single fly back transformer, which is able to harvest energy from multiple piezo-patches. In this proposed work, the DC power is generated using piezoelectric and MEMS. Then the Produced by DC energy is given to Ultra Low Power Converter Using with Micro controller then Ultra capacitor used to Highly Discharging in the DC power bank. The outputs of transducers are also given to micro controller. The obtained energy is boosted up using Booster Ultra Low Power Converter. The output of the Ultralow Power Converter is given to the Relay for the switching unit to store energy in a DC Power Bank and the stored energy is inverted to AC voltage
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Perooly, Soma S., Varun Garg, Md H. Rahman, L. W. Rosenberger, Gina S. Shreve, Ronald F. Gibson i G. W. Auner. "Determination of Elastic Modulus of Piezoelectric Aluminum Nitride Coating". MRS Proceedings 888 (2005). http://dx.doi.org/10.1557/proc-0888-v03-12.
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AbstractAluminum Nitride (AlN) is a technologically important wide band gap semiconductor and a potential piezo-electric material for Biosensor application [1]. It is a clear candidate for the integration of surface acoustic wave (SAW) devices on chips with silicon-based electronics [2]. AlN may also prove to be useful for the integration of mechanical devices and also in the field of packaging of Bio-MEMS devices because of its superior thermal conductivity 130-140 (W/mK, room temp-100 deg C) and nontoxicity. In the current work an attempt has been made to determine the elastic modulus of AlN coated on Si-microcantilevers, employing the concept of symmetrically laminated beam theory for the first time at the micro level thus avoiding the coupling effects. So far the earlier studies have been done only using simple beam theory. Modal vibration frequencies for microcantilevers without and with the AlN coating were used, along with analytical models and knowledge of the Si modulus, to “back out” the modulus of AlN [3].
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Linden, John, Neta Melech, Igor Sakaev, Ofer Fogel, Slava Krylov, David Nuttman, Zeev Zalevsky i Marina Sirota. "Femtosecond laser-assisted fabrication of piezoelectrically actuated crystalline quartz-based MEMS resonators". Microsystems & Nanoengineering 9, nr 1 (30.03.2023). http://dx.doi.org/10.1038/s41378-023-00511-5.
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AbstractA novel technology for the precise fabrication of quartz resonators for MEMS applications is introduced. This approach is based on the laser-induced chemical etching of quartz. The main processing steps include femtosecond UV laser treatment of a Cr-Au-coated Z-cut alpha quartz wafer, followed by wet etching. The laser-patterned Cr-Au coating serves as an etch mask and is used to form electrodes for piezoelectric actuation. This fabrication approach does not alter the quartz’s crystalline structure or its piezo-electric properties. The formation of defects, which is common in laser micromachined quartz, is prevented by optimized process parameters and by controlling the temporal behavior of the laser-matter interactions. The process does not involve any lithography and allows for high geometric design flexibility. Several configurations of piezoelectrically actuated beam-type resonators were fabricated using relatively mild wet etching conditions, and their functionality was experimentally demonstrated. The devices are distinguished from prior efforts by the reduced surface roughness and improved wall profiles of the fabricated quartz structures.
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Hsu, Yu-Hsiang, Tsung-Yu Chu, Zi-Xun Lin i Chih-Kung Lee. "A Gated Two-Frequency Two-Mode Method for Piezoelectric Motorization". ASME Letters in Dynamic Systems and Control 1, nr 4 (29.04.2021). http://dx.doi.org/10.1115/1.4050796.
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Abstract In this study, we present a new driving method to generate traveling waves in a finite plate for application to piezoelectric motors. Due to resonant modes which dominate the vibration of finite structures, methods to reduce resonant effects such as using an electric sinker or driving at a non-resonant frequency have been reported. To take advantage of natural resonance and to increase driving efficiency, a new method entitled gated two-frequency-two-mode (G-TFTM) was developed. A piezoelectric bimorph of 1.1 g weight with two rectangular actuators was implemented to verify the design concept. One actuator was operated at a first bending mode and the other actuator operated at a second bending mode with a phase difference. The driving signal was gated to generate an intermittent excitation to provide the periodic propulsion. To determine the profile of the induced traveling wave, an analytical solution was derived and a numerical model was used. Using these design tools, we experimentally verified that traveling waves can be generated using a G-TFTM method. A 0.1-g object can be moved at a speed of 3.31 mm/s under the condition of a 70-to-20 voltage ratio and a 137 deg phase difference. The moving direction was found to be reversed by changing the phase to −43 deg. The experimental and numerical data are detailed in this paper to demonstrate the feasibility of this G-TFTM method.
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Lan, Mengdie, Wenjun Yang, Xu Liang, Shuling Hu i Shengping Shen. "Vibration modes of flexoelectric circular plate". Acta Mechanica Sinica 38, nr 12 (6.09.2022). http://dx.doi.org/10.1007/s10409-022-22063-x.
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AbstractBeams, plates, and shells, as the fundamental mechanical structures, are widely used in microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) as sensors, actuators, energy harvesters, and among others. Deeply understand the electromechanical coupling of these dielectric structures is of crucial for designing, fabricating, and optimizing practice devices in these systems. Herein we demonstrate the electromechanical coupling in flexoelectric circular plate, in which higher-order strain gradients were considered to extend the classical electromechanical properties to isotropic materials, in which the non-uniform distribution of the electric potential along the radial direction was considered. Analytical solutions for the vibration modes of the flexoelectric circular plates showed that the dynamic modes were totally different from the piezoelectric circular plates owing to the inversion symmetry breaking by the strain gradient. The electromechanical coupling dynamic modes are sensitive to bending, twisting modes owing to the sensitivity of the flexoelectric effect to bending. This work provides a fundamental understanding of the electromechanical coupling in flexoelectric circular plate, which is helpful in designing novel flexoelectric circular plate-based devices, such as flexoelectric mirrors.
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Kuang, Linjuan, Jian Zhou, Yihao Guo, Huigao Duan i Yong Qing (Richard) Fu. "Versatile and Effective Design Platform for Surface Acoustic Wave Accelerometers". Physica Scripta, 19.07.2023. http://dx.doi.org/10.1088/1402-4896/ace8cd.
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Abstract Micro-Electro-Mechanical Systems (MEMS) accelerometers have great potentials for applications in aerospace, autonomous driving and consumer electronics. However, most of their working principles are based on capacitive and resistance types, which cannot be easily used for wireless and passive sensing, while surface acoustic waves (SAWs) are the key solution for this problem. Due to complex acoustic-electric-mechanical coupling during accelerator operations, currently, there needs an accurate, reliable, and efficient design and simulation platform to improve the structure and performance of SAW based accelerometers. In this work, we proposed an accurate, reliable, and efficient modeling platform to optimize designs of SAW accelerometers, using a double-ended cantilever beam structure as an example. This model integrated elastic acoustic effect and the coupled wave equations under both the mechanical and electrical loading using the finite element analysis, and obtained acceleration-frequency responses of the accelerators. We have systematically simulated effects of thickness of piezoelectric film, wavelengths, and structural parameters of cantilever beams, and the simulation results are well consistent with the theoretical results. Finally, using the developed model, we designed a high-G SAW accelerometer (up to 20000 g), which achieved a high sensitivity (-41.8 Hz/g) and excellent linearity (0.9999), and another high sensitivity accelerometer (3.02 KHz/g), with a good linearity (0.9999) over a 100 g acceleration range.
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Park, Joung-Man, Zuo-Jia Wang, Dong-Jun Kwon i Lawrence K. DeVries. "Optoelectronic and Interfacial Properties of CNT and ITO on Borosilicate Glass and PET Substrates with Nano- and Hetero-structural Aspects". MRS Proceedings 1258 (2010). http://dx.doi.org/10.1557/proc-1258-q04-23.
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AbstractNano- and hetero-structures of carbon nanotube (CNT) and indium tin oxide (ITO) can control significantly piezoelectric and optoelectronic properties in Microelectromechanical Systems (MEMS) as sensing and actuators under cyclic loading. Optimized preparation conditions were obtained for multi-functional purpose of the specimens by obtaining the best dispersion and turbidity in the solution. Optical transmittance and electrical properties were investigated for CNT and ITO dipping and spraying coating on boro-silicate glass and polyethylene terephthalate (PET) substrates by electrical resistance measurement under cyclic loading and wettability test. Uniform dipping coating was performed using Wilhelmy plate method due to it simple and convenience. Specimen was applied with spraying coating additionally. The change in the electrical and optical properties of coated layer is mainly dependent upon the number of dip-coating, the concentration of CNT and ITO solutions, and the surface treatment condition. Electric properties of coating layers were measured using four-point probe method, and surface resistance was calculated using a dual configuration method. Optical transmittance of CNT and ITO coated PET film was also evaluated using UV spectrum. Surface energy and their hydrophilic and hydrophobic properties of CNT and ITO coated substrates were investigated by wettability test via static and dynamic contact angle measurements. As the elapsing time of cyclic loading passed, the stability of surface resistance and thus comparative interfacial adhesion between coated layer and substrates was evaluated to compare the thermodynamic work of adhesion, Wa. As dip-coating number increased, surface resistance of CNT coating decreased, whereas the transmittance decreased step-by-step due to the thicker CNT and ITO networking layer. Nano- and hetero-structural effects of CNT and ITO solution on the optical and electrical effects have been studied continuously.
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Simcic, J., D. Nikolić, A. Belousov, D. Atkinson, C. Lee, S. Madzunkov i D. Almodiel. "Quadrupole Ion Trap Mass Spectrometer for Ice Giant Atmospheres Exploration". Space Science Reviews 217, nr 1 (18.01.2021). http://dx.doi.org/10.1007/s11214-020-00785-5.
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AbstractTo date, a variety of different types of mass spectrometers have been utilized on missions to study the composition of atmospheres of solar system bodies, including Venus, Mars, Jupiter, Titan, the moon, and several comets. With the increasing interest in future small probe missions, mass spectrometers need to become even more versatile, lightweight, compact, and sensitive.For in situ exploration of ice giant atmospheres, the highest priority composition measurements are helium and the other noble gases, noble gas isotopes, including 3He/4He, and other key isotopes like D/H. Other important but lower priority composition measurements include abundances of volatiles C, N, S, and P; isotopes 13C/12C, 15N/14N, 18O/17O/16O; and disequilibrium species PH3, CO, AsH3, GeH4, and SiH4. Required measurement accuracies are largely defined by the accuracies achieved by the Galileo (Jupiter) probe Neutral Mass Spectrometer and Helium Abundance Detectors, and current measurement accuracies of solar abundances.An inherent challenge of planetary entry probe mass spectrometers is the introduction of material to be sampled (gas, solid, or liquid) into the instrument interior, which operates at a vacuum level. Atmospheric entry probe mass spectrometers typically require a specially designed sample inlet system, which ideally provides highly choked, nearly constant mass-flow intake over a large range of ambient pressures. An ice giant descent probe would have to operate for 1-2 hours over a range of atmospheric pressures, possibly covering 2 or more orders of magnitude, from the tropopause near 100 mbar to at least 10 bars, in an atmospheric layer of depth beneath the tropopause of about 120 km at Neptune and about 150 km at Uranus.The Jet Propulsion Laboratory’s Quadrupole Ion Trap Mass Spectrometer (QITMS) is being developed to achieve all of these requirements. A compact, wireless instrument with a mass of only 7.5 kg, and a volume of 7 liters (7U), the JPL QITMS is currently the smallest flight mass spectrometer available for possible use on planetary descent probes as well as small bodies, including comet landers and surface sample return missions. The QITMS is capable of making measurements of all required constituents in the mass range of 1–600 atomic mass units (u) at a typical speed of 50 mass spectra per second, with a sensitivity of up to $10^{13}$ 10 13 counts/mbar/sec and mass resolution of $m/\Delta m=18000$ m / Δ m = 18000 at m/q = 40. (Throughout this paper we use the unit of m/q = u/e for the mass-to-charge ratio, where atomic mass unit and elementary charge are $1~\text{u} = 1.66\times 10^{-27}~\text{kg}$ 1 u = 1.66 × 10 − 27 kg and $1\text{e} = 1.6\times 10^{-19}$ 1 e = 1.6 × 10 − 19 C, respectively.) The QITMS features a novel MEMS-based inlet system driven by a piezoelectric actuator that continuously regulates gas flow at inlet pressures of up to 100 bar.In this paper, we present an overview of the QITMS capabilities, including instrument design and characteristics of the inlet system, as well as the most recent results from laboratory measurements in different modes of operation, especially suitable for ice giant atmospheres exploration.