Stretchable flexible electrodes based on in situ coating of graphite with PANI

Abstract

Stretchable bioelectrodes need both conductivity and deformation stability, but the conductive pathways of traditional rigid materials are prone to instability during stretching. In this study, polyaniline coated graphite powder (PANI@G) core shell fillers were constructed through the in situ oxidative polymerization of aniline and were sprayed onto a styrene-ethylene/butylene-styrene block copolymer (SEBS) substrate to prepare stretchable conductive films. The PANI coating layer improved the connection between graphite lamellae through interfacial interactions among nitrogen containing groups, oxygen containing functional groups, and conjugated structures. As a result, the film retained approximately 89% of its initial current at 75% strain, and the current drift was only 2.3% during 126 min of continuous stretching at 50% strain. The film was further patterned into lightweight flexible electrodes and realized electrical signal acquisition induced by electrical stimulation, providing an effective strategy for wearable flexible electrodes.