Stretchable PEDOT:PSS composite electrodes enabled by a soft-chitosan interface for wearable electromyographic sensing

A soft-chitosan interface was developed for composite flexible electrodes. • The interface bridged SEBS and PEDOT:PSS through multiple interactions. • The fabricated electrode remained stable under extreme and cyclic tensile strain. Flexible conductive electrodes used for wearable electrophysiological sensing are frequently limited by interfacial instability arising from insufficient intercomponent interaction and elastic mismatch under repeated mechanical deformation. In this study, a soft-chitosan interfacial system was introduced into styrene-ethylene-butylene-styrene (SEBS)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composite electrodes to enhance structural integrity and electrical stability during tensile loading. Glycerol and Tween 80 were employed to maintain chitosan chains in a soft and deformable state, allowing the interfacial layer to penetrate the porous SEBS substrate through capillary action and form rivet-like anchoring structures. Simultaneously, hydrogen bonding and electrostatic attraction between the interfacial layer and the PEDOT conductive layer established effective interfacial coupling. Benefiting from this cooperative interface design, the resulting composite electrode exhibited stable conductivity retention under large tensile strain and cyclic stretching conditions. In addition, the electrode enabled reliable electromyographic (EMG) signal monitoring of the forearm and masseter muscles with stable waveform acquisition during motion. These results demonstrate the potential of the developed electrode for wearable electrophysiological sensing applications. This work provides an interfacial engineering strategy for stretchable conductive electrodes requiring stable electrical performance under mechanical deformation. Download: Download high-res image (296KB) Download: Download full-size image