IEEE Trans Biomed Circuits Syst. 2020 Dec;14(6):1241-1252. doi: 10.1109/TBCAS.2020.3037862. Epub 2020 Dec 31.
This paper presents the first wireless and programmable neural stimulator leveraging magnetoelectric (ME) effects for power and data transfer. Thanks to low tissue absorption, low misalignment sensitivity and high power transfer efficiency, the ME effect enables safe delivery of high power levels (a few milliwatts) at low resonant frequencies ( ∼ 250 kHz) to mm-sized implants deep inside the body (30-mm depth). The presented MagNI (Magnetoelectric Neural Implant) consists of a 1.5-mm 180-nm CMOS chip, an in-house built 4 × 2 mm ME film, an energy storage capacitor, and on-board electrodes on a flexible polyimide substrate with a total volume of 8.2 mm . The chip with a power consumption of 23.7 μW includes robust system control and data recovery mechanisms under source amplitude variations (1-V variation tolerance). The system delivers fully-programmable bi-phasic current-controlled stimulation with patterns covering 0.05-to-1.5-mA amplitude, 64-to-512- μs pulse width, and 0-to-200-Hz repetition frequency for neurostimulation.
本文提出了第一款利用磁电（ME）效应进行功率和数据传输的无线可编程神经刺激器。由于组织吸收率低、不对准灵敏度低和功率传输效率高，ME 效应能够以低谐振频率（约 250 kHz）将几毫瓦的高功率水平安全地传输到体内深处的毫米级植入物（30 毫米深度）。所提出的 MagNI（磁电神经植入物）由一个 1.5 毫米厚的 180 纳米 CMOS 芯片、一个内部制造的 4×2 毫米 ME 薄膜、一个储能电容器以及一个带有电路板的柔性聚酰亚胺基板上的电极组成，总体积为 8.2 毫米。该芯片的功耗为 23.7 μW，包括在源幅度变化（1V 变化容限）下的稳健系统控制和数据恢复机制。该系统可提供完全可编程的双相电流控制刺激，刺激模式涵盖 0.05 至 1.5mA 幅度、64 至 512 μs 脉冲宽度和 0 至 200Hz 重复频率，用于神经刺激。
