Self‐adhesive and biocompatible dry electrodes with conformal contact to skin for epidermal electrophysiology

Abstract Long‐term biopotential monitoring requires high‐performance biocompatible wearable dry electrodes. But currently, it is challenging to establish a form‐preserving fit with the skin, resulting in high interface impedance and motion artifacts. This research aims to present an innovative solution using an all‐green organic dry electrode that eliminates the aforementioned challenges. The dry electrode is prepared by introducing biocompatible maltitol into the chosen conductive polymer, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate). Thanks to the secondary doping and plasticizer effect of maltitol, the dry electrode exhibits good stretchability (62%), strong self‐adhesion (0.46 N/cm), high conductivity (102 S/cm), and low Young's modulus (7 MPa). It can always form a conformal contact with the skin even during body movements. Together with good electrical properties, the electrode enables a lower skin contact impedance compared to the current standard Ag/AgCl gel electrode. Consequently, the application of this dry electrode in bioelectrical signal measurement (electromyography, electrocardiography, electroencephalography) and long‐term biopotential monitoring was successfully demonstrated.