Tesi sul tema "Piezoelectric sensor"
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Pantzare, Sandra, e Elin Wollert. "Wireless Piezoelectric Horse Sensor System". Thesis, Linköpings universitet, Fysik och elektroteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-150152.
Testo completoSharapov, V. M., K. V. Bazilo e R. V. Trembovetskaya. "Electro-Acoustic System with Piezoelectric Sensor". Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41006.
Testo completoAhmadi, Mehdi. "Energy Harvesting Wireless Piezoelectric Resonant Force Sensor". Thesis, University of North Texas, 2013. https://digital.library.unt.edu/ark:/67531/metadc407829/.
Testo completoZhang, Ruizhi. "ARTERIAL WAVEFORM MEASUREMENT USING A PIEZOELECTRIC SENSOR". VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/126.
Testo completoHolmes, J. E. "Novel piezoelectric structures for sensor and actuator applications". Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399477.
Testo completoMika, Bartosz. "Design and testing of piezoelectric sensors". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1565.
Testo completoTheaker, Brenden John. "Volatile Sensing Using Coated Piezoelectric Quartz Crystal Sensor Arrays". Thesis, Teesside University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518736.
Testo completoAgyemang, Duah Joseph Agyemang Duah. "A PIEZOELECTRIC POWERED BLUETOOTH LOW ENERGY TEMPERATURE SENSOR PLATFORM". University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1533124081986125.
Testo completoTharakan, Zacharia. "Fabrication and Characterization of Piezoelectric Zinc Oxide Nanowire Sensor". OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2268.
Testo completoDhayal, Vandana Sultan Singh. "Exploring Simscape™ Modeling for Piezoelectric Sensor Based Energy Harvester". Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984261/.
Testo completoLuo, Hongyu Shih Wei-Heng Shih Wan Y. "Colloidal processing of PMN-PT thick films for piezoelectric sensor applications /". Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/500.
Testo completoDong, Biqin. "Cement-based piezoelectric ceramic composites for sensor applications in civil engineering /". View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202005%20DONG.
Testo completoSubbaramaiah, Rashmi. "Design of Vibration-Sourced Piezoelectric Harvester for Battery-Powered Sensor Networks". Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10690961.
Testo completoEnergy harvesting is an important aspect in the field of energy and power systems. Utilizing road vibrations as the source to harvest energy has gained demand previously and advanced study on implementing distinctive designs for vibration sourced harvesters are currently in progress. A vibration sourced piezoelectric energy harvester design with road vibrations as the input source is proposed in this thesis and the outputs to validate the harvester design are simulated from the software COMSOL Multiphysics. The design comprises of two PZT-5J mass-spring oriented cantilever bimorphs to capture the road vibrations and three silicone rubbers to increase the stress applied on the bimorphs. A productive piezoelectric energy harvester is implemented to work in low and high vibration conditions and maximum power output of 57mW is obtained by the simulation. The results obtained prove piezoelectric energy harvesting design as an efficient design that can be used to serve sensors and wireless applications.
Oliveira, Éder Luiz. "Application of piezoelectric materials as sensor and actuator for aeroelastic investigation". Instituto Tecnológico de Aeronáutica, 2014. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=3038.
Testo completoSun, Fanping. "Piezoelectric active sensor and electric impedance approach for structural dynamic measurement". Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-08292008-063023/.
Testo completoLund, Anja. "Melt spun piezoelectric textile fibres : an experimental study". Doctoral thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-3682.
Testo completoPakdel, Zahra. "Characterization, Modeling of Piezoelectric Pressure Transducer for Facilitation of Field Calibration". Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/76791.
Testo completoMaster of Science
Krsmanovic, Dalibor. "High temperature ultrasonic gas flow sensor based on lead free piezoelectric material". Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/245065.
Testo completoXia, YuXin M. B. A. Sloan School of Management. "Self-powered wireless sensor system using MEMS piezoelectric micro power generator (PMPG)". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37091.
Testo completoIncludes bibliographical references (leaves 99-102).
A thin-film lead zirconate titanate, Pb(Zr,Ti)03, MEMS Piezoelectric Micro Power Generator (PMPG) has been integrated with a commercial wireless sensor node (Telos), to demonstrate a self-powered RF temperature sensor module. PMPG and a power management module are designed to satisfy sensor node's power requirement. An electro-mechanical model of PMPG has been developed to maximize power output. The 2nd generation PMPG is designed to provide 0.173 mW power at 3 V DC with a natural frequency of 155.5 Hz. The power management module is developed to provide AC-DC rectification, energy storage, and active switching between PMPG and application circuit. To minimize power consumption, sensor data is taken at a discontinuous interval. A test bed is developed, which mimics that of a liquid gas pipeline used in the Alaska, where the self-powered sensor be used to monitor pipeline temperature.
by YuXin Xia.
M.Eng.
Tran, Prenn Xuan. "A Study of Measuring Intracranial Pressure Using a Non-Invasive Piezoelectric Sensor". Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/52573.
Testo completoMaster of Science
Ajitsaria, Jyoti K. Choe Song-Yul. "Modeling and analysis of PZT micropower generator". Auburn, Ala, 2008. http://hdl.handle.net/10415/1489.
Testo completoMiller, Ross James. "Artificial Skin Tactile Sensor For Prosthetic and Robotic Applications". DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/435.
Testo completoLi, Menghui. "Fabrication of reliable, self-biased and nonlinear magnetoelectric composites and their applications". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/50656.
Testo completoPh. D.
Abbas, Syed Farhat. "Development of a low cost shock pressure sensor". Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1182538469.
Testo completoHahn, Dale. "Biofilm response to isopropanol in an aqueous environment measured by a piezoelectric sensor". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0007/MQ43168.pdf.
Testo completoVAHLBERG, ANNA. "Textile Sensor Using Piezoelectric Fibers for Measuring Dynamic Compression in a Bowel Stent". Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17999.
Testo completoProgram: Textilteknik
Falconi, Daniel Rodrigo. "Sensor piezelétrico baseado na tecnologia dos eletretos termo-formados: aprimoramentos dos processos de produção". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/18/18152/tde-20042010-095926/.
Testo completoThis work describes two improvements on the production of piezoelectric sensors, which are based on thermo-formed electrets technology. These sensors which were previously prepared by fusing and molding two Teflon FEP films into bubbles structures in a hot-press system, presented piezoelectric coefficients over 300 pC/N after properly electrical charging. However, this production system still presents many technical challenges, most of them concerning the bubble formation. With the improvements, called hot lamination and cold adhesive, a much better control of the distribution, height and diameter of the air bubbles could be obtained. These improvements process can be described into four main stages: the molding of one film; the sticking process of the two films; the metallization of their surfaces followed by electric charging. The sticking processes and the previous molding of the film are crucial and the great contribution of this work. With these contributions not only better sensor could be made but it also facilitated the industrial scale implementation of the sensors. Another expressive contribution of this work was the development of a system to measure the piezoelectric coefficient.
RUNDQVIST, KARIN. "Piezoelectric behaviour of woven constructions based on poly(vinylidene fluoride) bicomponent fibres". Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17386.
Testo completoProgram: Masterutbildning i textilteknik,
Saini, Navtej Singh. "UHF RFID Sensor Tag for Tire Monitoring". The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1480629684843769.
Testo completoZhang, Chen. "Piezoelectric-Based Gas Sensors for Harsh Environment Gas Component Monitoring". Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1538769/.
Testo completoLin, Xiao. "Structural Health Monitoring using Geophysical Migration Technique with Built-in Piezoelectric Sensor/Actuator Array". NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010324-152020.
Testo completoLamb waves based ultrasonic testing has been studiedfor many years. However, conventional methods of generatingand collecting of Lamb waves usually require bulky instruments and manual interference, thus can not be applieddirectly for in-situ or in-service monitoring of thestructural health. Especially, the method of interpretingthe Lamb waves in an active structural health monitoring(SHM) system with built-in piezoelectric sensors/actuatorsis not available yet. The objective of this study was to propose and validate, through numerical simulation and experimental studies, the feasibility of adopting the geophysical migration method to interpret the ultrasonic Lamb wave signals for the purpose of realizing quantitative damage identification. A homogeneous isotropic plate with a surface-mountedlinear piezoelectric ceramic (PZT) disk array is studied as an example. The piezoelectric disks act as actuators to excite Lamb waves and also as sensors to receive the waves reflected from the structural anomaly in the plate. The migration technique, which is an advanced technique in geophysics to reverse the reflection wave field and to image the Earth interior, is then used to back-propagate the recorded wave signals and to visually image the damage in the plate. Mindlin plate theory is adopted to model the propagating waves, and a two-dimensional 2-6 order explicit finite difference algorithm is used to synthesize the reflection waves and to implement the migration process. The stability and accuracy criteria of the finite differencealgorithm when used in plate problems is discussed. An analytical solution is derived for the transient Lamb waves of an infinite plate subject to a point loading. This solution is used to verify the accuracy of the finite difference calculation. Both poststack and prestack migration are studied to propagate the reflection energy back to the damages. For the poststack migration, a one-way version of flexural wave equation is derived and the data pre-processing procedures before migration, such as muting direct arrival, deconvolution and stacking, are discussed. For prestack migration, an excitation-time imaging condition specifically for the migration of waves in a plate is introduced based on ray-tracing concepts and the asymptotic properties of flexural wave velocities and the migration is proceeded through the full-way wave equation. The results of numerical simulation show that the migration method possesses the capability of identifying multiple discrete damages without a priori assumption on the distribution pattern of the damages. Thus not only the existence but also the shape and the dimensions of the damages can be visually identified. An experimental apparatus is then set up to validate the conclusions drawn from the synthetic data. For calibration of the system, an analytical model of the waves in a plate incorporated with PZT sensors/actuators is developed. The agreement between the model calculated data and the measured data in the experiment shows that A0 mode Lamb waves are accurately generated and collected. Finally, the migration results from the reflection waves of an artificial damage in an arc shape recorded in the experiment are presented. It is shown that the existence of the damage could be correctly imaged through the migration process as it was shown in the numerical simulation.
Morales, Connor. "Piezoelectric Sonar Sensor Design and Use for Bathymetric Map Creation by Unmanned Aerial Vehicles". Thesis, University of the Pacific, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10602509.
Testo completoA genetic algorithm from literature is adapted to design piezoelectric sonar sensors using results from physics simulations to optimize for a uniform voltage response over a wide range of frequencies. The adapted genetic algorithm produces valid sensor designs, and algorithm improvements are proposed. The best case general methods for bathymetric mapping with a sonar sensor is determined by sweeping various point selection algorithms, interpolation algorithms, and algorithm parameters. A set of methods are proposed based on how many sample points are used and what error metric is preferred. Additional algorithms are suggested for future improvements.
Lin, Chih-Ting, e 林致廷. "Redeployment of Piezoelectric Point Sensor by Using Distributed Piezoelectric Sensor Technology". Thesis, 1998. http://ndltd.ncl.edu.tw/handle/01602834485433449821.
Testo completo國立臺灣大學
應用力學研究所
86
Point sensors and distributed sensors have both been developed for several decades. The advantages of point sensors as compared to distributed sensors are quite different and both have their own limitations. Based on the linear piezoelectric sensor theory, piezoelectric point sensors and piezoelectric distributed sensors have been developed. A sensor model has been investigated and established. The experimental result to verify the unique characteristics of the piezoelectric sensor as well as the distributed point sensor. Based on the integrated distributed and point sensor, an innovative distributed accelerometer has been developed. The design principle as well as application implications of this newly developed accelerometer are detailed.
TSENG, WEI-MING, e 曾韋銘. "Wearable piezoelectric telescopic intelligent sensor". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/mny259.
Testo completo國立中正大學
機械工程系研究所
105
This research presents a multifunctional and stretchable smart patch. This patch contains the piezoelectric (PZT film) node array for sensing acoustic emission (AE) wave and thermally activated PNIPAM nodes for delivering drug. The PZT sensing node array is realized on a thin flexible titanium sheet with serpentine network electrically connected. This design has two novelties: (1) the serpentine network allows the node array to stretch in an arbitrary planar direction; (2) the normal force of AE detection head coupling to the sensing object can be enhanced while the patch stretched. The thermal actuator and temperature controlled drug release module both fabricated with PNIPAM is also reported for the first time.
Cheng, Tzong-Jih, e 鄭宗記. "Piezoelectric Quartz Crystal Sensor for". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/62893536958367343626.
Testo completo國立成功大學
醫學工程研究所
89
This study utilizes piezoelectric quartz crystal (PQC) sensors as an analytical tool for biomedical applications. Application fields contain blood coagulation tests, developing an affinity biosensor and interfacial study by integrating an electrochemically analytical technology. This investigation aims to extend the applications of PQC sensors to clinical tests, and to developing novel biosensors and basic interfacial sensor research. Topics covered herein include blood coagulation studies and the development of an affinity biosensor. The contents of each chapter are listed below: Part 1: Determination of plasma prothrombin time using a PQC sensor. The extent to which a PQC sensor was influenced by liquid viscosity was studied herein, as was the sensor’s application to estimating blood coagulation time and its application to estimating blood coagulation time. The relationship between the frequency shift (Df) of PQC and the physical properties of the contacting liquid was also examined. Glycerol solutions with various weight percentages were adjusted to various viscosities. The Df is inversely linearly proportionate to (rlhl)1/2 in general blood conditions (0.14 s-1/2g-1cm2.). The sensing function to liquid density and viscosity was utilized to monitor blood coagulation and determine coagulation time in real time. PQC sensors with adequate sensitivity to slight viscosity changes are employed to monitor blood coagulation. The case of an anticoagulated plasma specimen, prothrombin time (PT) was determined by the PQC sensor based on the introduction of tissue thromboplastin (TF) and calcium ion. The PQC data reveals that the best linear relation ship in a double-logarithmic plot of PT versus TF concentration in the range of 5.466 ~ 22.311 units/ml appeared at 90% of the total frequency shift. The PQC result was compared with a commercial optical coagulometry and showed a strong linear correlation (ca. 0.98). The PQC sensor can potentially be used in basic hematology research owing to its real time monitoring capability, which overcomes the drawbacks of the end-point method used in traditional coagulometers. Furthermore, the PQC sensor has an advantage in satisfying future demand for bedside and home-care products in that only a 20 ml sample is required for testing. Part 2: Determining heparin levels in blood with activated partial thromboplastin time using a PQC sensor. A PQC sensor was used to determine both whole blood activated partial thromboplastin time (WBaPTT) and plasma activated partial thromboplastin time (PLaPTT) induced by anticoagulant heparin. The PQC sensor results revealed a linear relationship between WBaPTT (or PLaPTT) and heparin levels in clinically relevant concentrations (0~0.4 unit/ml). The mean of individual R2 (= 0.9491) for a regressive curve between WBaPTT and heparin concentrations was shown sufficiently clearly. The PQC method can be employed to assess the influence of heparin through determining WBaPTT, since its sensitivity (P< 0.01) is comparable to that of aPTT by optical coagulometry (OCaPTT). Furthermore, the results of WBaPTT with various heparin concentrations (n = 9) were found to be closely correlated with those of OCaPTT (correlation coefficient = 0.9441). Linear calibration plots were extended into 3 units/ml of heparin in PLaPTT and WBaPTT. Measured results indicate that the prototype coagulometer based on PQC sensor has a closer linear relationship than the optical coagulometer in high-dose ranges of heparin. It has been suggested that the PQC method is more convenient, which may be useful in clinical situations for rapid monitoring heparin therapy using a small volume (20 ml) of whole blood specimens. The PQC method has three advantages in heparin assay: rapid analysis (from 80 to 600 sec), wide detection range (0~3.0 units/ml) and convenient sample preparation (whole blood is available). Part 3: Studies of whole blood coagulation using PQC sensors. This section builds on the previous two chapters regarding applications of PQC sensors to hematological studies, and particularly in assessing the practicability of applying PQC sensors to whole blood coagulation tests. Long-term (3000 sec) and real time viscosity monitoring was conducted during whole blood clotting. Viscosity is insignificant in PQC responses between whole blood and plasma. A step-like response curve is also obtained from analyzing whole blood coagulation within 1000 seconds, an acceptable time period, in clinical trials. A comparison of responses between whole blood and plasma coagulation does not reveal interferences on the surface of the PQC sensor by cells and proteins in blood. Additionally, it is practical to apply the PQC sensor to studies of whole blood coagulation via research on whole blood recalcification time. A PQC sensor was used to determine whole blood clotting time (CT) to quantitatively analyze heparin concentrations in blood. An obvious linear relationship existed between whole blood CT and heparin concentration from 0 to 0.1 units/ml, but the examination took over 1000 seconds. Consequently, while the results are analytically useful, the approach not be practical for application in clinics. Whole blood activated partial thromboplastin time (aPTT) was determined using a PQC sensor to investigate high concentrations of heparin in-vitro and ex-vivo. Ten thousand units of heparin were injected into each subject undergoing heparin treatment following a cardio catheter. Plasma aPTT could not be determined in over half of the blood sample using a commercially optical coagulometer. PQC sensors conducted all of the tests and the test results reveal an appropriate linear relationship, indicating the effectiveness of PQC in discriminating between anticoagulation and a normal condition. The “receiver operating characteristic” plot was used to comparatively assess sensitivity and specificity between different coagulation analyzers. The analytical results revealed that PQC performs better in distinguishing heparin anticoagulation than an optical coagulometer. Part 4: Development of a heparin sensor based on PQC. This investigation attempted to develop a heparin sensor for clinical use, possessing directive assessment, easy operability and a wide calibration range. Absolute concentrations of heparin in phosphate buffer solution (PBS, pH 7.4) were determined using PQC as an affinity biosensor, and electrochemical impedance spectroscopy (EIS) was used to investigate immobilization of protamine and heparin assay. Constructing a heparin sensor requires using protamine as a specifically recognized elements and using simple physical adsorption as an immobilization method to develop a heparin sensitive surface on a PQC gold electrode. The effectiveness of physical adsorption in immobilizing protamine was confirmed by examining the preparation condition, including incubation time and protamine concentration. The reduction in oscillating frequency of PQC (ca. -100 Hz) was maximized when applying 20 mg/ml protamine in PBS with a 20 minute incubation period. Heparin adsorption onto protamine-modified electrode in PBS revealed an exponential-like binding curve, and a long time was required to reach the steady state in the PQC frequency response. Furthermore, judging from the initial slope (df/dt) and frequency change (Df) of PQC two linear calibration curves were obtained after a binding interval (600 seconds) for heparin concentrations from 0 to 3.0 and 7.0 units/ml, respectively. Ten thousand ppm of bovine serum albumin (BSA) was used as mimic plasma to assess the interference of proteins in blood with a protamine-modified sensory surface. Interference causing a —50 Hz frequency shift will influence the sensing function of the heparin sensor, but might not be lethal. The EIS system was corporately employed to investigate preparation procedures and the sensing function of heparin sensors. In EIS analysis, calibration curves with a linear concentration range of 0~3.0 units/ml were also obtained for heparin in PBS when ferrocyanide was used as an electroactive marker. The EIS method will be conducive to designing micro sensing arrays that allow the development of inexpensive biosensors.
Li, Chia-Hsien, e 李佳賢. "Development of flexible piezoelectric vibration sensor". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/51465862951700893573.
Testo completo國立中興大學
機械工程學系所
100
In this study, a single-mode piezoelectric sensor for the detection of low-frequency vibration mechanical failure is developed. To have the single-mode sensor to be operated at low frequency, we deposited the PZT-silica composite films on a PI-copper flexible substrate at 150C by sol-gel technology. The advantage of using low-frequency single-mode sensor for the detection of mechanical failure is that no extra signal process system is required and vibration is able to be estimated by the output voltage directly in order to enhance the practicability and reduce the system cost. Experimental result showed that developed sensors operated at 76Hz. When the frequency is shifted by 5HZ, the sensitivity plummets by 50%. Due to the significant change, we can tell whether the vibration frequency of low-frequency machineries is shifted. As for the output, the sensitivity of sensors is large than 60mV/g. The sensors also were able to be used at large deflection test. After repetitions of testing, the change of sensitivity was less than 10%. Thus, when knocking occurs, our sensor has better endurance. The sensor output was able to detect vibration at specific frequency by scaling the signal and the signal process system could be simplified instead of using the spectrum technique. Keyword: Single-mode, flexible, low-frequency, piezoelectric sensor
Bhat, Sudhakar. "Piezoelectric sensor for foot pressure measurement". 1989. http://catalog.hathitrust.org/api/volumes/oclc/22288872.html.
Testo completoTypescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 11-12).
Garg, Atul. "Development Of Piezoelectric Thin Film Based Acoustic Sensor". Thesis, 2004. https://etd.iisc.ac.in/handle/2005/1207.
Testo completoGarg, Atul. "Development Of Piezoelectric Thin Film Based Acoustic Sensor". Thesis, 2004. http://etd.iisc.ernet.in/handle/2005/1207.
Testo completoShie, Dung-ting, e 謝東廷. "Development of PZT Piezoelectric Sensor for Microbalance". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/05365324161518550268.
Testo completo國立中央大學
電機工程研究所
97
In this research, microbalance devices were developed with piezoelectric material to measure biomass based on change of resonant frequency. The sensor structure consists of a square piezoelectric PZT thin film. The Pb1.2(Zr0.52Ti0.48)O3 (PZT) thin film was prepared on Pt/Ti/SiO2/Si surface by sol-gel coating method. We designed different sizes of working area (50 × 50 μm2, 100 × 100μm2, 250 × 250μm2, 400 × 400μm2) and verified piezoelectric properties of these PZT devices. The crystallization and microstructure of the PZT thin films were characterized by X-ray diffraction and scanning electron microscopy (SEM). In this result, the PZT thin film annealed at 700℃ for 50 min showed single-phase perovskite peaks. SEM micrograph revealed that the PZT film with thickness of about 600 nm has uniform microstructure without any cracks. In the electrical properties, the leakage current density rose as the piezoelectric working areas increased. The C-V property exhibited complete butterfly patterns, whose symmetry increased with increasing piezoelectric working areas. Besides, the tunability at 250 × 250μm2 working area was maximum, hence it has excellent piezoelectric characteristic. Further, we used potassium hydroxide (KOH) wet etching technique to reduce the backside thickness.This device has great potential for biomolecular detection.
Chien, Bo-Ru, e 簡伯儒. "Blood Pressure Measurement Based On Piezoelectric Sensor". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8264w6.
Testo completoTzeng, Yau-Shiuan, e 曾耀萱. "Piezoelectric Energy-harvesting Circuit for Wireless Sensor Modules". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/ks5fd7.
Testo completo國立臺北科技大學
電能轉換與控制產業碩士專班
102
The main purpose of this study is to design a vibratory energy-harvesting system and integrate it with a ZigBee wireless sensor module. The concept behind the vibratory energy-harvesting system is collecting mechanical vibration energy and transforming it into electrical energy, which can be used as a supplying power for any electronic device. Most of the available vibratory energy harvesters (VEHs) capture only minute amounts of energy, as a result external power supplies or battery are required as auxiliary power sources. This, thereby, reduces the practicality and convenience of VEHs. Besides the additional power consumption by the sensing modules, the energy generated by the piezoelectric material is a minimal of about 5 ~ 9mW making it inadequate for driving any general common electronic device. Therefore the goal of this study is study the application on low-power wireless sensor modules. In this study, the Arduino LilyPad microcontroller is used in conjunction with a super capacitor to manage and control both the energy converted by the piezoelectric material and the data from the wireless sensor. However, this study uses four pieces of piezoelectric material for the 16.84 mW required by the microcontroller alone . The differences between input current of the piezoelectric material (on the μ level) and the maximum open-circuit voltage (multiples of 10V) makes it necessary to place energy storage, transmission circuit and a DC-DC converter at the front-end of the microcontroller for the control and protection of the input node. the microcontroller, control, energy saving (sleep mode) and data transmission process are achieved. As the system does not require any external power and batteries due to the adequate amount of power provided by the piezoelectric material, the objective of power self-sufficiency is achieved.
Lo, Wen-Bin, e 羅文濱. "Flexible piezoelectric tactile sensor with structural electrodes array". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31139458310626099986.
Testo completo南台科技大學
機械工程系
95
The tactile sensor has flexible characteristic that it can be applied in the application with the human body physiological monitoring for example,pulse, heartbeat, blood pressure. However the piezoelectric-type tactile sensor sensitivity needs to be improved. Therefore we introduce the concept of structural electrode for enhancement of the sensitivity of piezoelectric tactile sensor and fabricated structure by MEMS process. A sandwich structure for flexible tactile sensor consists of top and bottom soft substrates made of Polystyrene, and in between of two soft substrates a piezoelectric thin film, PVDF, and patterned different area, are utilized as sensing material and microstructures, respectively and used shaker and force sensor. We design our experiment of tactile sensing system. The signal of a contact pressure to the tactile sensor are sensed and processed in the DAQ System. Finally the signals are integrated for taking the force profile. The processed signals of the output of the sensor are visualized on LabVIEW in personal computer in real time. A rudimentary tactile object image measurement procedure for applied loads has been devised to recognize the silhouette of a sharp edge, square, ,circle, the shape and force distribution of the contact object are obtained using two and three-dimensional image in real time.
Shin, Min-Sheng, e 施敏升. "Modeling and Analysis of Piezoelectric Actuator and Sensor". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/51348357441529910644.
Testo completo中原大學
機械工程研究所
90
This paper is an advance research about the actuator and sensor both driven by piezoelectric principle. For the actuator, this paper built series of theoretical model of piezoelectric bimorph actuator in both static and dynamic states and applied that theoretical model in the vibration system of parts feeder. We also simulation and analysis about the motion path of parts. The motion of parts has also been built theoretically to design the necessary vibration frequency and amplitudes. We hope to get the best transferring efficiency. The load capacity of the system is one of the important reasons to effect transferring efficiency. So the load capacity is one of the subjects in this paper. Finally, we test the real parts feeder. We can get a better transferring rate, safety, and precision when the parts feeder has higher operating frequency. For the sensor, this paper built series of theoretical model of vibration gyroscope. And research the relation about the angular speed with resonant frequency. The most important character of vibration gyroscope is its frequency of drive and detect should be quite close. That’s can get better sensitivity. However, you may not find it in many research reports. The vibration beam gyroscope which research by this paper, it’s frequency of input and output almost the same. So we can get the gyroscope has better sensitivity.
Shrikanth, V. "A Non Resonant Piezoelectric Sensor for Mass, Force and Stiffness Measurements". Thesis, 2015. http://etd.iisc.ernet.in/2005/4000.
Testo completoShrikanth, V. "A Non Resonant Piezoelectric Sensor for Mass, Force and Stiffness Measurements". Thesis, 2015. http://etd.iisc.ac.in/handle/2005/4029.
Testo completoGuzmán, Sierra Dayana Lizethe. "Flexible piezoelectric bionanocomposites for biomedical sensors". Master's thesis, 2018. http://hdl.handle.net/10773/25894.
Testo completoNas últimas décadas, tem havido um interesse crescente no desenvolvimento de novos materiais com o intuito de alcançar a "Internet of Things (IoT)" que prevê a ligação de 20 a 30 bilhões de dispositivos à internet até 2020. A implementação da “Internet of Things” exige o desenvolvimento de tecnologia base, onde se incluem os dispositivos de captação de energia, atuadores e sensores. Os sensores são muitas vezes utilizados em aplicações biomédicas que exigem flexibilidade, biocompatibilidade e sustentabilidade. Neste contexto, a motivação deste trabalho foi a preparação de um bionanocompósito para sensores piezoelétricos biocompatíveis para aplicações biomédicas. Assim, escolheu-se como matriz um polissacarídeo que tem a capacidade de formar películas (filmes) facilmente, e partículas de titanado de bário que é um material ferroeléctrico e piezoeléctrico à temperatura ambiente, não possuindo chumbo na sua composição. As partículas de BaTiO3 foram sintetizadas por método hidrotermal a temperatura moderada (200 °C) e na ausência de solventes orgânicos. Foram estudadas vários tempos de reação de forma a selecionar as condições ideais para a preparação das partículas com as propriedades adequadas para a incorporação nos filmes à base de quitosana. A caracterização estrutural por difração de raios-X (DRX) e espectroscopia de Raman permitiu verificar que as partículas sintetizadas a 200 °C apresentavam, ao fim de 24 horas de síntese, a estrutura cristalográfica tetragonal bem definida. As partículas mostraram morfologia cúbica uniforme e tamanho médio de cerca de 306 nm. Em geral, os tamanhos das partículas e de cristalites aumentam com o tempo de reação. Os filmes foram obtidos pelo método de evaporação de solvente, após a dispersão das partículas, em diferentes proporções, numa solução de quitosana. As propriedades estruturais (DRX) e morfológicas (SEM); físico-químicas (mecânicas, grau de humidade, solubilidade em água e ângulo de contacto e Raman); e elétricas (comportamento dieléctrico, curvas de histerese e resposta piezoelétrica à escala nanométrica) dos filmes foram caracterizadas. A adição de partículas melhorou as características mecânicas dos filmes de quitosana, tornando-os mais resistentes, elásticos e dúcteis. Estes filmes revelaram também serem mais resistentes à água, o que revela que existe uma interação entre as partículas e a matriz de quitosana. Em relação ao comportamento elétrico dos filmes, o aumento de partículas melhora a permitividade das amostras cinco vezes em relação ao material biopolimérico. Foi verificada uma grande dificuldade de deposição de elétrodos nos filmes flexíveis que se pode justificar com base nas características das amostras e/ou na inadequação das condições experimentais de deposição dos elétrodos na amostra. Como não foi possível medir a resposta piezoeléctrica à escala macroscópica, nem polarizar uma área da amostra de bionanocompósito, fez-se o estudo da resposta piezoelétrica à escala nanométrica por microscopia atómica de resposta piezoelétrica. Os filmes com a concentração mais elevada de nanopartículas mostraram claramente domínios piezoelétricos, não sendo, contudo, possível traçar uma curva de histerese aceitável nem polarizar uma pequena área do nanocompósito. Esta observação, juntamente com a análise por microscopia de potencial de superfície do filme controlo (só de quitosana) que indica a presença de cargas no polímero puro, leva à conclusão da existência de um comportamento do tipo electret pelo que será necessário encontrar uma estratégia para eliminar (ou reduzir) a contribuição da matriz. Apesar das dificuldades encontradas, os bionanocompóstos desenvolvidos, à base de quitosana e titanato de bário são promissores para serem usados em dispositivos biomédicos (por exemplo em compressas para libertação de fármacos, etc.) devido à sua elevada resistência mecânica, elasticidade e ductilidade, sendo adaptados a condições de elevado grau de humidade. Estes bionanocompósitos são ainda biocompatíveis e parcialmente biodegradáveis, tendo potencial para serem usados como alternativa aos polímeros sintéticos
Mestrado em Materiais e Dispositivos Biomédicos
Gokhale, Nikhil Suresh. "Studies On The Development Of Piezoelectric Thin Flm Based Impact Sensor". Thesis, 2008. https://etd.iisc.ac.in/handle/2005/770.
Testo completoGokhale, Nikhil Suresh. "Studies On The Development Of Piezoelectric Thin Flm Based Impact Sensor". Thesis, 2008. http://hdl.handle.net/2005/770.
Testo completoGarcia, Juan Elias. "Piezoelectric transducer built-in self-test for logging while drilling instrument sensor evaluation at rig site". Thesis, 2014. http://hdl.handle.net/2152/26344.
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