Electromechanical characterization of piezoresistive carbon-elastomer composites

Stretchable electronic conductors are an important class of material enabling electroactive polymer (EAP) research. One of the most common approaches to creating a stretchable conductor is to embed conductive particles within a nonconductive matrix material to create a composite with favourable electromechanical properties. Whether an EAP device employs these composites for specific functions like strain sensing or simply as deformable electronic interconnects, the interplay between mechanical deformation and electronic conductivity frequently emerges as a central concern. While these materials are simple to produce, the relationship between mechanical strain and changes in electrical resistivity (piezoresistivity) can be complex and difficult to predict, and the factors that influence this behaviour are not well understood. This study focused on the comprehensive electromechanical characterization of various samples of piezoresistive elastomer composites. The work examined how a range of factors such as filler loading, matrix material, strain properties, additives, and production methodologies affected the piezoresistive properties of these composites. This work identifies key factors that can affect the magnitude, time dependence, and even direction of piezoresistivity. By identifying important influencing factors, the results of this work are intended to assist researchers in designing materials that are best suited for their specific use case.