Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 26 for “"piezoelectric sensor"”.
-
ARTERIAL WAVEFORM MEASUREMENT USING A PIEZOELECTRIC SENSOR
… monitor peripheral arterial pulse using a PVDF piezoelectric sensor. After comparing different locations of sensor placement, a specific sensor wrap for the finger was developed. Its composition, size, and location make it inexpensive and very convenient to use. In order to monitor the …
-
A drifter-based self-powered piezoelectric sensor for ocean wave measurements
In the present research, a drifter-based piezoelectric sensor is proposed to measure ocean waves’ height and period. To analyze the motion principle and the working performance of the proposed drifter-based piezoelectric sensor, a dynamic model is developed. The developed dynamic model investigates …
-
A Study of Measuring Intracranial Pressure Using a Non-Invasive Piezoelectric Sensor
… This thesis presents a study of a non-invasive sensor using piezoelectric PVDF wire to measure the ICP. The PVDF wire sensor is wrapped around the outer portion of the human head to measure the integrated hoop strain. Using this hoop strain, the pressure is then calculated from a known coupling …
-
An improved finite element model for vibration and control simulation of smart composite structures with embedded piezoelectric sensor and actuator
A thesis submitted in candidacy for the Degree of Doctor of Technology: Electrical Engineering, Technikon Natal, Durban, South Africa, 2001.
-
Additively Manufactured Flexible Piezoelectric Wave-Based Multifunctional Sensor
<p>The demand for acoustic wave-based sensors has rapidly increased in the aerospace, chemical, gas, and biological fields due to their versatility in sensing measurands. This study aims to develop a flexible piezoelectric sensor exhibiting enhanced piezoelectric properties using additive …
-
Structural Health Monitoring Using Multiple Piezoelectric Sensors and Actuators
A piezoelectric impedance-based structural health monitoring technique was developed at the Center for Intelligent Material Systems and Structures. It has been successfully implemented on several complex structures to detect incipient-type damage such as small cracks or loose connections. However, …
-
Towards Cyber-Physical Security for Additively Manufactured Parts via In Situ Monitoring and Electromechanical Impedance
… of metal AM part identification via a low-cost piezoelectric sensor-actuator able to record a part frequency response that is dependent on the geometry and material properties of the part as a whole, (3) an exploration of part-to-part variation across AM processes, again measured via a …
-
Dynamic pressure sensors for hypersonic flow measurements
… research and development of an acoustic pressure sensor tailored for hypersonic boundary layer flow measurements. Hypersonic boundary layer flows comprise shocks, laminar-to-turbulent transitions, and high-frequency turbulence with small (sub 1-mm) characteristic length scales. Non-invasive …
-
Dynamics and Control of Smart Structures for Space Applications
… a flexible manipulator with a collocated piezoelectric sensor/actuator pair for active vibration control, and a piezoelectric nanopositioner for control of instrumentation. Shape memory alloys are used to control the surface flatness of a prototype membrane structure. As these actuators …
-
Aeroelastic modeling and flutter control in aircraft with low aspect ratio composite wings
… of an aircraft model. In addition, wing mounted piezoelectric sensor and induced-strain actuator patches were used in conjunction with active feedback control laws to increase the airspeed at which body-freedom flutter occurs. Two control laws were tested, coupled and independent modal position …
-
Fiber-optic sensors for weigh-in-motion application
… collection. The existing WIM systems utilizing piezoelectric cables have been shown to result in rather large random errors of up to 12% and need to be installed at permanent sites. In addition, the exponential decay of the output signal of the piezoelectric cable with time can cause …
-
Investigating structure and chemistry in functional ferroelectric ceramics via transmission electron microscopy
… This system is studied for its potential use in piezoelectric sensor and actuators as a replacement for lead-based materials, currently used in these devices. The search for such a replacement has been driven by the threat of EU regulations regarding the use of lead-based materials in devices, …
-
Control of a flexible space robot tracking a moving target
… suppression control is concerned, the use of the piezoelectric sensor/actuator pairs dispersed along the flexible arms is proposed. Collocated sensors/actuators for vibration control exhibit good performance. The actuators are designed to compensate for the disturbances caused by the rigid-body …
-
Ultra-low-power circuits and systems for wearable and implantable medical devices
Advances in circuits, sensors, and energy storage elements have opened up many new possibilities in the health industry. In the area of wearable devices, the miniaturization of electronics has spurred the rapid development of wearable vital signs, activity, and fitness monitors. Maximizing the time …
-
Low Power Adaptive Wireless Circuits for the Internet of Things and In-body implants
… their designs: whether it is energy harvesting, sensor interface, security accelerators, or wireless protocols and MAC algorithms. While these approaches have delivered significant performance improvements, they remain inherently constrained by the performance of each respective layer. This …
-
Innovative Platform Design for In Vitro Primary Blast Injury Research
… wire was vaporized and generated a shock wave. A piezoelectric sensor near the wide end of the tank recorded the passing of the shock wave, which was used to derive various pressure metrics that correlate to injury. The sample size for each combination of diameter and material was five, with a …
-
Computation Of The Response Of Thin Piezoelectric Films
… order to calculate the output charge of a thin piezoelectric film bonded to a shell structure. The method is applied to cases of a cylindrical shell structure, as well as a beam and plate for both generic and shaped piezoelectric films. An overview of the fundamentals of shell vibration theory …
-
Effects of temperature on the electrical impedance of piezoelectric elements
… Material Systems and Structures, employs piezoelectric (PZT) materials for tracking the structural impedance to qualitatively identify damage. The mechanical impedance of a structure is a function of the structure's mass, stiffness, damping, and structural boundary conditions. Changes in …
-
Methods for Validation of a Turbomachinery Rotor Blade Tip Timing System
… developed test method used an instrumented piezoelectric blade to create known dynamic deflections. The active vibration rotor was able to create measureable deflection over a range of frequencies centered on the first bending mode of the blade. The results for the 110 Hz, 150 Hz, 180 Hz …
-
S-Schichtproteine als molekulare Bausteine zur Funktionalisierung mikroelektronischer Sensorstrukturen
… für die Beschichtung von vorstrukturierten Sensoroberflächen, für die mikrofluidische Reaktionsräume geschaffen werden. Durch optimierte Reaktionsbedingungen wird unter Nutzung des Selbstorganisationsvermögens der Proteinmonomere eine großflächige Beschichtung von Substratoberflächen …
Page 1 of 2