Tuning Mechanical and Electrical Properties of Elastomer Composites with Hybrid Filler Network Containing Graphene for Stretchable Strain Sensors

Abstract

Conductive elastomer composites (CECs) with segregated filler networks display a combination of good mechanical properties and electrical conductivity, enabling potential applications in flexible and stretchable electronics. However, it is challenging to achieve high strain sensitivity and to retain good elasticity. Here, hybrid fillers of carbon nanostructures (CNS, also known as branched carbon nanotubes) and graphene are used to achieve high strain sensitivity of thermoplastic polyurethane (TPU)‐based CECs without decreasing elasticity and electrical conductivity. By changing the graphene type, namely, single layer graphene nanosheet (GNS) and graphene nanoplatelets (GNP), mechanical properties and strain–sensing performances of the CECs can be modulated effectively at proper hybrid filler compositions. Due to the effect of graphene morphology, the TPU/CNS–GNP system has higher strain sensitivity by comparison with the TPU/CNS–GNS system. These CECs demonstrate potential applications as flexible/wearable electronics in body joint bending and flexible switches and resistors for current regulation.