IEEE Trans Neural Syst Rehabil Eng. 2018 May;26(5):1093-1099. doi: 10.1109/TNSRE.2018.2824281.
This paper reports on the modeling and characterization of capacitive elements with tissue as the dielectric material, representing the core building block of a capacitive link for wireless power transfer to neural implants. Each capacitive element consists of two parallel plates that are aligned around the tissue layer and incorporate a grounded, guarded, capacitive pad to mitigate the adverse effect of stray capacitances and shield the plates from external interfering electric fields. The plates are also coated with a biocompatible, insulating, coating layer on the inner side of each plate in contact with the tissue. A comprehensive circuit model is presented that accounts for the effect of the coating layers and is validated by measurements of the equivalent capacitance as well as impedance magnitude/phase of the parallel plates over a wide frequency range of 1 kHz-10 MHz. Using insulating coating layers of Parylene-C at a thickness of and Parylene-N at a thickness of deposited on two sets of parallel plates with different sizes and shapes of the guarded pad, our modeling and characterization results accurately capture the effect of the thickness and electrical properties of the coating layers on the behavior of the capacitive elements over frequency and with different tissues.
本文报告了一种以组织为介电材料的电容元件的建模和特性分析，该电容元件是无线电力传输到神经植入物的电容式链路的核心构建模块。每个电容元件由两个平行板组成，它们围绕组织层排列，并采用接地保护电容垫，以减轻杂散电容的不利影响，并屏蔽极板免受外部干扰电场的影响。极板还在内侧涂上一层生物相容性的绝缘涂层，与组织接触的每块极板的内侧都涂上一层。提出了一个全面的电路模型，该模型考虑了涂层的影响，并通过测量平行板的等效电容以及在 1 kHz-10 MHz 的宽频率范围内的阻抗幅度/相位来验证。使用厚度为和厚度为的 Parylene-C 绝缘涂层，沉积在具有不同尺寸和形状的保护垫的两组平行板上，我们的建模和特性分析结果准确地捕捉了涂层的厚度和电特性对电容元件在不同组织和频率下的行为的影响。
