Scalable manufacturing of conductive rubber nanocomposites with ultralow percolation threshold for strain sensing applications

Abstract

Abstract Conductive elastomer composites (CECs) based on carbon nanofillers are deemed as intriguing candidates for the next generation flexible sensors. However, it is challenging to achieve scalable and eco-friendly manufacturing of CECs-based flexible sensors with low percolation threshold and reliable sensing performance. Herein, instead of the conventional chemical functionalization in toxic solvent, we present a facile and green surface modification strategy of carbon nanotubes (CNTs) by silane coupling agent with the assistance of water/ethanol solvent to fabricate natural rubber/CNTs nanocomposites. The proved high utilization efficiency of CNTs endows the CECs with ultralow percolation threshold (0.15\u202fwt%). Meanwhile, the strong interfacial interaction between CNTs and polymer matrix contributes to their excellent tensile strength (23.83\u202fMPa) and toughness (159.57\u202fMJ/m3). Taking these advantages, the nanocomposites-based flexible sensors exhibit high sensitivity (GF\u202f=\u202f19.6) with a wide strain sensing range (ca. 150%), which are able to accurately monitor both large- and small-scale human motions and possess reliable piezoresistive sensing performance. We believe this strategy will benefit the exploration of carbon-based nanocomposites for applications in strain sensors, artificial muscle, electromagnetic shielding, etc.