Highly stretchable, sensitive and healable polyurethane-urea/graphene nanocomposite sensor for multifunctional applications
Yu Yin, Zhaoyang Xu, Lisheng Xu, Yikuan Li, Tianqing Liu, Qingshi Meng, Xiao Su, Hsu‐Chiang Kuan, Jiabin Dai, Jun Ma
Abstract
Flexible wearable electronic devices offer promising potential for monitoring physiological signals. However, creating a single sensor that integrates high tensile strength, sensitivity, self-healing capabilities, and a wide working range presents a significant and multifaceted challenge. This study reports a novel nanocomposite consisting of polyurethane-urea elastomer (PUU) and graphene nanoplatelets (E-GNPs) that are mechanochemically modified with diethyltoluene diamine ethacure 100. A low electrical percolation threshold was observed at 4.17 vol% E-GNPs. The sensor based on the PUU nanocomposite at 7 vol% of graphene has revealed a gauge factor up to 17.57 and a wide working range of 361.76% with high tensile strength of 19.73 MPa. It can withstand 20,000 cycles at 50% strain. The sensor exhibits negative temperature dependence at 20–100 °C, with a resolution of 0.01/°C at 36–40 °C. Treatments with solvents and heat enable a healing efficiency for sensitivity of up to 70.46%. The healable sensor enables real-time monitoring of temperature and strain signals, making it ideal for wearable devices in human health and sports monitoring.