Electrically compensated, tattoo-like electrodes for epidermal electrophysiology at scale
Youhua Wang, Lang Yin, Yunzhao Bai, Siyi Liu, Liu Wang, Ying Zhou, Chao Hou, Zhaoyu Yang, Hao Wu, Jiaji Ma, Yaoxin Shen, Pengfei Deng, Shuchang Zhang, Tangjian Duan, Zehan Li, Junhui Ren, Lin Xiao, Zhouping Yin, Nanshu Lu, YongAn Huang
Abstract
Epidermal electrophysiology is widely carried out for disease diagnosis, performance monitoring, human-machine interaction, etc. Compared with thick, stiff, and irritating gel electrodes, emerging tattoo-like epidermal electrodes offer much better wearability and versatility. However, state-of-the-art tattoo-like electrodes are limited in size (e.g., centimeters) to perform electrophysiology at scale due to challenges including large-area fabrication, skin lamination, and electrical interference from long interconnects. Therefore, we report large-area, soft, breathable, substrate- and encapsulation-free electrodes designed into transformable filamentary serpentines that can be rapidly fabricated by cut-and-paste method. We propose a Cartan curve-inspired transfer process to minimize strain in the electrodes when laminated on nondevelopable skin surfaces. Unwanted signals picked up by the unencapsulated interconnects can be eliminated through a previously unexplored electrical compensation strategy. These tattoo-like electrodes can comfortably cover the whole chest, forearm, or neck for applications such as multichannel electrocardiography, sign language recognition, prosthetic control or mapping of neck activities.