Design of Wearable Flexible Antenna for Transcutaneous Wireless Power Transfer
Xu Qi*, Feng Chenyu, Sun Yuan
(Key Laboratory of Image Processing and Intelligent Control of Education Ministry, School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan 430074, China)
Abstract：The bidirectional peripheral nerve interface (PNI) can help to rebuild the sensory function of amputees. In this work, a flexible wearable antenna was proposed to enable a focused midfield wireless power for the implanted PNI. To generate a focused field, a symmetrical quadruple-feed antenna of 60 mm×60 mm was slotted to optimize the surface current distribution. The simulation results showed that the resonant frequency of the antenna was 1.524 GHz with the absolute bandwidth of 1.385~1.726 GHz, the resonant frequency offsets were less than 0.2 GHz for the bent antennas with the curvature radius varying from 60 mm to 110 mm. The simulated magnetic field intensity at the implanted receiver was 0.012 A/m, 0.058 A/m, and 0.065 A/m for in-phase excitation, time-reversed phase excitation, and orthogonal phase excitation, respectively. The experimental results showed that the resonant frequency of the proposed antenna was 1.531 GHz with the absolute bandwidth of 1.401~1.765 GHz, the variations of the antenna frequency due to curvature were less than 0.3 GHz with the curvature radius of 60 mm, 80 mm, and 100 mm. The measured magnetic fields at the receiver within the simulated tissue gel, generated by the antenna with the time-reversed phase excitation (0.045 A/m) and the orthogonal phase excitation (0.049 A/m) were much greater than that by using the in-phase excitation (0.0035A/m). In conclusion, the symmetrical quadruple-feed antenna with the time reversed phase excitation or the orthogonal phase excitation can generate observable focusing effect.
[1] Kim K. A review of haptic feedback through peripheral nerve stimulation for upper extremity prosthetics [J]. Current Opinion in Biomedical Engineering, 2022, 21: 100368. [2] Tan DW, Schiefer MA, Keith MW, et al. A neural interface provides long-term stable natural touch perception[J]. Science Translational Medicine, 2014, 6(257): 257ra138-257ra138. [3] George JA, Kluger DT, Davis TS, et al. Biomimetic sensory feedback through peripheral nerve stimulation improves dexterous use of a bionic hand [J]. Science Robotics, 2019, 4(32): eaax2352. [4] Zhang Peng, Ma Xuan, He Jiping. A bidirectional peripheral neural interface for restoring sensorimotor function of non-human primates [C]//2016 IEEE Information Technology, Networking, Electronic and Automation Control Conference. Chongqing: IEEE, 2016: 420-423. [5] Zhang Yingchao, Zheng Ning, Cao Yu, et al. Climbing-inspired twining electrodes using shape memory for peripheral nerve stimulation and recording[J]. Science Advances, 2019, 5(4): eaaw1066. [6] Cho Y, Park J, Lee C, et al. Recent progress on peripheral neural interface technology towards bioelectronic medicine [J]. Bioelectronic Medicine, 2020, 6(1): 1-10. [7] Barman SD, Reza AW, Kumar N, et al. Wireless powering by magnetic resonant coupling: recent trends in wireless power transfer system and its applications [J]. Renewable and Sustainable Energy Reviews, 2015, 51: 1525-1552. [8] Kurs A, Karalis A, Moffatt R, et al. Wireless power transfer via strongly coupled magnetic resonances [J]. Science, 2007, 317(5834): 83-86. [9] Le-Huu H, Seo C. Bipolar spiral midfield wireless power transfer for cardiac implants application [J]. IEEE Antennas and Wireless Propagation Letters, 2021, 20(9): 1631-1635. [10] Gabriel S, Lau RW, Gabriel C. The dielectric properties of biological tissues: III. parametric models for the dielectric spectrum of tissues [J]. Physics in Medicine & Biology, 1996, 41(11): 2271-2293. [11] Koohestani M, Pires N, Skrivervik AK, et al. Performance study of a UWB antenna in proximity to a human arm [J]. IEEE Antennas and Wireless Propagation Letters, 2013, 12: 555-558. [12] Freeman DK, Byrnes SJ. Optimal frequency for wireless power transmission into the body: Efficiency versus received power [J]. IEEE Transactions on Antennas and Propagation, 2019, 67(6): 4073-4083. [13] Kim S, Poon ASY. Optimizations of source distribution in wireless power transmission for implantable devices[C]//2010 IEEE Antennas and Propagation Society International Symposium. Toronto: IEEE, 2010: 1-4. [14] Poon ASY, O'Driscoll S, Meng TH. Optimal frequency for wireless power transmission into dispersive tissue [J]. IEEE Transactions on Antennas and Propagation, 2010, 58(5): 1739-1750. [15] IT IS Foundation. Tissue frequency chart [DB/CP]. https://itis.swiss/virtual-population/tissue-properties/database/tissue-frequency-chart/,2021-06-20/2023-12-28. [16] 谢处方, 饶克谨, 杨显清,等. 电磁场与电磁波 [M](第五版). 北京: 国防工业出版社, 2019. [17] Wang Zhiliang, Lin Qin, Chen Qingyue, et al. Flexible UWB antenna fabricated on polyimide substrate by surface modification and in situ self-metallization technique [J]. Microelectronic Engineering, 2019, 206: 12-16. [18] Samal PB, Chen SJ, Zhang Qun, et al. A PDMS-based low-profile monopole antenna for wearable applications[C]//2022 IEEE MTT-S International Microwave Biomedical Conference (IMBioC). Suzhou: IEEE, 2022: 271-273. [19] GB 21288-2007, 移动电话电磁辐射局部暴露限值 [S]. [20] Costanzo S, Cioffi V, Qureshi AM, et al. Gel-like human mimicking phantoms: Realization procedure, dielectric characterization and experimental validations on microwave wearable body sensors [J]. Biosensors, 2021, 11(4): 111. [21] TekBox. FAQ tekbox near field probes[EB/OL]. https://www.tekbox.com/product/FAQ_Near_Field_Probes.pdf,2022-03-20/2024-02-27. [22] Chabalko MJ, Sample AP. Electromagnetic time reversal focusing of near field waves in metamaterials[J]. Applied Physics Letters, 2016, 109(26): 263901.
