Self-healing epoxidized natural rubber flexible sensors based on hydrogen bonding interactions†

Abstract

Flexible strain sensors find extensive applications in the domains of human health monitoring and human–computer interactions. At present, the exploration and development of a novel generation of flexible sensors exhibiting excellent sensitivity, high sensing performance, and sustainability have emerged as a crucial scientific and technological research endeavor. In this study, epoxidized natural rubber (ENR) with enhanced mechanical tensile and self-healing properties was fabricated by using ENR as the matrix and introducing reversible hydrogen bonding through modified nanofillers. The modified ENR exhibited good tensile strength (1.27 MPa) and elongation at break (1028%), and the self-healing efficiency reached 80% within 12 h at 45 °C. By incorporating nano carbon powder and multi-walled carbon nanotubes as a conductive interlayer, the composite exhibited good electrical conductivity, enabling it to provide a low detection limit, a wide sensing range, fast response time, and the cyclic tensile testing can be repeated 800 times. Consequently, the sensor can monitor subtle human movements and recognize different vocalizations and joint motions, suggesting potential applications in healthcare devices, flexible electronics, and human–machine interfaces.