Poly(vinyl alcohol)/polyacrylamide double‐network ionic conductive hydrogel strain sensor with high sensitivity and high elongation at break
Zijian Wu, Xiaorui Liu, Qi Xu, Liying Zhang, Safaa N. Abdou, Mohamed M. Ibrahim, Jing Zhang, Zeinhom M. El‐Bahy, Ning Guo, Junguo Gao, Ling Weng, Zhanhu Guo
Abstract
Abstract As a soft material with biocompatibility and stimulation response, ionic conductive hydrogel‐based wearable strain sensors show great potential across a wide spectrum of engineering disciplines, but their mechanical toughness is limited in practical applications. In this study, freeze‐thawing techniques were utilized to fabricate double‐network hydrogels of poly(vinyl alcohol)/polyacrylamide (PVA/PAM) with both covalent and physical cross‐linking networks. These double‐network hydrogels demonstrate excellent mechanical performance, with an elongation at break of 2253% and tensile strength of 268.2 kPa. Simultaneously, they also display a high sensitivity (Gage factor, GF = 2.32 at 0%–200% strain), achieve a rapid response time of 368 ms without the addition of extra conductive fillers or ions, stable signal transmission even after multiple cycles, and fast response to human motion detection.