Multi-dimensional flexible reduced graphene oxide/polymer sponges for multiple forms of strain sensors

Since sensors could be used for detecting multiple forms of mechanical deformations, we present a simple method for fabricating highly sensitive strain sensors using a conductive graphene/polymer sponge which is self-assembled by graphene flakes in the porous structure of the sponge. The graphene composite sponges exhibit outstanding electromechanical properties and can be processed into different dimensional sensors easily to detect multiple forms of mechanical deformations including tensile strain, impact, bending, vibrating and twisting. Although the sensitivity of the three-dimensional sensor is only 1.33 N-1, one-dimensional sensor exhibits high sensitivity up to 18.5 N-1. In addition, the one-dimensional sensor can evaluate human life activity, such as finger wag and even the impact caused by a hair. The shape of the graphene composite sponge can easily be arbitrarily customized in order to sense more accurately in practical applications. (C) 2017 Elsevier Ltd. All rights reserved.