Abstract
Here, we present an approach to incorporate graphene nanosheets into a silicone rubber matrix via solid stabilization of oil-in-water emulsions. These emulsions can be cured into discrete, graphenecoated silicone balls or continuous, elastomeric films by controlling the degree of coalescence. We characterize the electromechanical properties of the resulting composites as a function of interdiffusion time and graphene loading level. With conductivities approaching 1 S m-1, elongation to break up to 160% and a gauge factor of ~20 in the low-strain linear regime, we can accurately measure small strains such as pulse. At higher strains, the electromechanical response exhibits a robust exponential dependence, allowing accurate readout for higher strain movements such as chest motion and joint bending. The exponential gauge factor is found to be ~20, independent of loading level and valid up to 80% strain; this consistent performance is due to the emulsiontemplated microstructure of the composites. The robust behavior may facilitate high-strain sensing in the non-linear regime using nanocomposites, where relative resistance change values in excess of 107 enable highly accurate bodily motion monitoring.