Metamaterial-based Compact and Efficient Wireless Power Transfer System for Biomedical Implants
Project/Area Number |
21K04178
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 21060:Electron device and electronic equipment-related
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Research Institution | Kyushu University |
Principal Investigator |
Pokharel R.K. 九州大学, システム情報科学研究院, 教授 (60398568)
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Project Period (FY) |
2021-04-01 – 2024-03-31
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Project Status |
Granted (Fiscal Year 2021)
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Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2023: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2022: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2021: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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Keywords | 無線電力伝送 / メタマテリアル / 埋込型センサ / Metamaterial / Wireless Power Transfer / biological implants / high efficiency |
Outline of Research at the Start |
Wireless power transfer (WPT) to biomedical implants/devices suffers from the bulky receivers and very low efficiency inside biological tissues. In this proposal, a new design theory for a compact inductor’s model with stacked metamaterial layers will be presented to overcome these issues. The unit cell of the proposed stacked metamaterial shields each other from the tissue, which results in an improvement in the quality factor of the shielded unit cells and thus further improves the coupling between the transmitter and receiver. This also results in the increment of power transfer distance.
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Outline of Annual Research Achievements |
We have developed a metasurface of low magnetic losses and employed it to design a a compact WPT system to biomedical implants. We have also proposed the design theory of a low inductance value to overcome the problem of frequency shifting and misalignment. We verified the proposed design by conducting experiments using chicken meat bought at an ordinary grocery shop. The performance of the proposed system was satisfactory as expected.
This brief presents a compact and efficient resonance-shift insensitive wireless power transfer (WPT) system. This is possible by using a small electrical length defected ground structure (DGS) resonator, which is found effective against the resonance-shift phenomenon resulted from the higher permittivity of the tissue. Tissue has two undesired effects on a WPT system: (i) reduced coupled quality factor, and (ii) self-resonance shifting that leads to mismatch loss. So, the efficiency of a WPT system degrades in a tissue environment. Then, using the small electrical length DGS, we build a WPT transmitter (TX) using three cooperative DGS resonators to mitigate both issues. The fabricated prototype operates at 49 MHz in the air and tissue. This shows no change in operating frequency when the same receiver (Rx) is kept in the air or embedded inside tissues, which proves the effectiveness of the proposed cooperative DGS-WPT system against the resonance shift. The measured efficiency is 62% when the RX is embedded inside the tissue and is 68% in the air.
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Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
Everything went very well and we also achieved the experimental results as expected. Thig might be due to our long background on electromagnetic theory and its accurate simulation techniques we have achieved so far.
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Strategy for Future Research Activity |
In this year, we plan to develop another type of metasurface which has lower magnetic losses than the one that we proposed last year. This will further increase the efficiency and help to develop more compact WPT system.
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Report
(1 results)
Research Products
(5 results)