Self-Repairable Hybrid Piezoresistive-Triboelectric Sensor Cum Nanogenerator Utilizing Dual-Dynamic Reversible Network in Mechanically Robust Modified Natural Rubber

Abstract

The greener alternatives to tactile-integrated multimodal sensors with self-powered and self-healing abilities are highly desirable for all-in-one autonomous sensing systems, particularly impressive in diverse application ranges including smart home, healthcare, and e-skin. The dynamically self-healable, stretchable piezoresistive sensors, and triboelectric nanogenerators (TENGs) reported herein are constructed by a facile, industrially viable method of grafting imidazolium ions on epoxidized natural rubber (ENR) backbone. Owing to cation-π and π–π interaction between the percolated carbon nanotubes (CNTs)-network and the imidazolium ions formed by non-covalent interactions, the interfacial adhesion between the filler and elastomer is shown to improve considerably. The sensors show high piezoresistive strain sensitivity, reversible ionic network-assisted self-healability (efficiency ≈80%) and wide-ranging detectability for precise monitoring of human movements. Both the healed and pristine sensors feature low hysteresis and stable electrical outputs over a wide strain range (≤200%). While achieving rapid self-healing efficiency, the substrates are shown to exhibit remarkable robustness for harsh climates owing to significant mechanical toughness. Supported by excellent triboelectric tactile sensitivity (2.12 V N−1), the multifunctional TENG-enabled sensor yields superior power density (0.16 mW cm−2). Moreover, the TENG module exhibits high force sensitivity and ease of operation that are considered versatile for all-weather integrated tactile solutions for future technology.