Wearable graphene-based sensor array for finger tracking

In this work, we have developed novel flexible strain sensors based on an highly interconnected three-dimensional Polyurethane (PU) foam coated with a Polyvinyl alcohol (PVA)-multilayer graphene nanoplatelets (MLGs) paint. The electromechanical response of the sensors embedded in a biocompatible elastomer is firstly investigated through quasi-static tensile tests. The measured resistance variation under an applied stress confirmed the piezoresistive behavior of the fabricated sensors, showing a gauge factor of 8 at strain of 20%. Finally, we also demonstrated the feasibility to use an array of three sensors to monitor the flexion/ extension of finger joints.