Structurally tunable conductive wood sponge incorporated with PEDOT: PSS for enhanced piezoresistive sensor applications

Wearable strain sensors are gaining popularity in the field of intelligent electronic devices due to their compactness and mobility. In this study, we presented a wearable, pliable piezoresistive sensor derived from a wooden sponge integrated with the conductive polymer PEDOT. The conductive network of PEDOT: PSS underwent modulation through the incorporation of a cross-linking agent, namely, γ- glycidoxypropyltrimethoxysilane (GOPS), aimed at enhancing the sensor's sensitivity. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed that GOPS cross-linked with PEDOT: PSS. Crosslinking induced by GOPS helped PEDOT to form an ideal-network microstructure, thereby improving the sensitivity. Benefitting from this micro-network structure, the wood sponge/PEDOT:PSS/GOPS (WPG) exhibited a high sensitivity of 5.69 kPa⁻¹ and a fast response time of 111 ms, with exceptional stability and durability (over 500 cycles), making it suitable for detecting subtle muscle changes. Crosslinking induced by GOPS induced PEDOT to form an ideal-network microstructure, thereby improving the sensitivity. The micro-network structure presented a novel approach for designing piezoresistive sensors.