Nano Foldaway Skin-like E-interface for Detecting Human Bioelectrical Signals

Flexible electrodes applied to different positions of the human body to detect bioelectrical signals need to be conductive with respect to both the skin and the external circuit. However, electrodes fabricated with micromachining can only be made conductive on one side, which requires inserting connection wires, thus affecting skin adhesion and leading to a more fragile circuit on the soft substrate. This paper proposes an e-interface designed with an innovative folding transfer process, which can fold nanometer thick electrodes in a macroscopic way. Avoiding the difficulties of fabricating double layer as well as an insulation layer, the e-interface is not only skin-conformable for long-term wear but also provides a stable connecting pad for the subsequent circuit by its double-sided conductivity. The e-interface can be stretched to more than 25% of its original length and achieve electrical stability in the long-term signal acquisition. A responsive ECG signal is obtained by the e-interface, and the signal remains stable during exercise.