Dissertation
SIMULATION ANALYSIS AND EXPERIMENTAL VALIDATION OF ULTRASOUND ENERGY TRANSFER IN THE NEAR FIELD TO CHARGE MEDICAL IMPLANTS
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000006443
Handle:
https://hdl.handle.net/2376/118958
Abstract
Acoustic power transfer technology is a method for wirelessly transfer energy to implantable medical devices. The advantage of ultrasonic power transfer over inductive power transfer is in the longer-distance range between the transmitter and receiver. Inductive power transfer is more powerful and even has high efficiency if the distance is in the order of the transmitter diameter orless. Nevertheless, in some cases short-distance ultrasonic power transfer may be employed; consequently, their operation may be complicated by the near-field aspects of acoustic energy transfer. Rapidly varying characteristics of the near-field region present challenges to experimental investigation.
A piezoelectric energy transfer system consisting of two lead zirconate titanate (PZT) transducers is analyzed and tested, focusing on the near-field in this work. To facilitate this study, simulation analysis was used to investigate the effects on the voltage output of simultaneous variations of multiple pairs of physical parameters, such as changing the diameters of both receiver and transmitter. These physical parameters have been used to model, analyze, and simulate the performance of a piezoelectric ultrasonic energy transfer system using COMSOL Multiphysics software then validate experimentally. Moreover, the effect of the thickness ratio and diameter ratio on the power transfer efficiency was observed to be significant when the transmitter thickness was 1 mm. The simulation results indicated that changing multiple parameters simultaneously was more effective for energy transfer than changing individual parameters. The effects of operating frequency on power transfer efficiency at various distances between transmitter and receiver were also studied. It was found that the frequencies below 1 MHz showed almost zero power transfer efficiency regardless of the distance between two PZT transducers. The rotation angle that represents the misalignment between the PZT receiver and transmitter can make the power transfer efficiency change significantly by a few degrees. Finally, simulation analysis for influence of perfect match layers in terms of material and thickness on power transfer efficiency is provided.
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Details
- Title
- SIMULATION ANALYSIS AND EXPERIMENTAL VALIDATION OF ULTRASOUND ENERGY TRANSFER IN THE NEAR FIELD TO CHARGE MEDICAL IMPLANTS
- Creators
- Ammar Mohammed
- Contributors
- Changki Mo (Advisor)John Miller (Advisor)Joseph Iannelli (Committee Member)David Lowry (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Mechanical and Materials Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 96
- Identifiers
- 99900592259101842
- Language
- English
- Resource Type
- Dissertation