Dry electrode for the measurement of biopotential signals

• Published in: Science China. Information sciences 2011-11, Vol.54 (11), p.2435-2442
• Main Authors: Wang, Yu, Pei, WeiHua, Guo, Kai, Gui, Qiang, Li, XiaoQian, Chen, HongDa, Yang, JianHong
• Format: Article
• Language: English
• Subjects: Arrays; Computer Science; Drying; Electrodes; Etching; Frequency ranges; Impedance; Information Systems and Communication Service; Needles; Recording; Research Papers; Skin preparations; Visual; 各向同性; 湿法刻蚀; 生物信号; 电位信号; 电极测量; 皮肤过敏; 视觉诱发电位; 阻抗测试
• ISSN: 1674-733X; 1869-1919
• DOI: 10.1007/s11432-011-4354-0

This paper introduces a kind of silicon-based dry electrode for measuring biological signals. It uses microneedle arrays to penetrate into the stratum corneum to reduce skin impedance. The dry electrode requires neither skin preparation nor the electrolytic gel, is easy to use and causes no skin allergy. Two different tech- nologies are chosen to manufacture microneedle arrays of dry electrode. One is deep dry etching combined with isotropic wet etching. The other is mechanical dicing combined with chemical wet etching （including isotropic wet etching and anisotropic wet etching）. Microneedle arrays are coated with metal and divided into 25 mm2 as dry electrode patch. Impedance testing shows that the impedance value of dry electrode can be comparable with that of commercial electrode in the 20 Hz-10 kHz frequency range. The steady-state visual evoked potential recording and analysis prove that the dry electrode can be used to detect electroencephalography.