A porous graphene/polydimethylsiloxane composite by chemical foaming for simultaneous tensile and compressive strain sensing

With the rapid development of flexible electronics, flexible sensors and wearable devices have attracted great attention for their wide applications. Using porous structure is one of the most common ways to enhance the sensing performance. Here, we report a new chemical foaming method, using ammonium bicarbonate powders to prepare porous composites, adopting polydimethylsiloxane as matrix and graphene as conductive fillers, is used to detect both tensile and compression strains. Not only the porous structure but also the strain itself enhance the sensitivity of the sensors, which is further explained by the finite element analysis.