Piezoresistive response of spray-printed carbon nanotube/poly(vinylidene fluoride) composites

The performance of piezoresistive materials based on carbon nanotubeipoly(vinylidene fluoride), CNT/PVDF, composites prepared by spray printing is reported. It is shown that for a CNT concentration close to the percolation threshold, where the piezoresistive response is the largest, the electromechanical response, characterized by the gauge factor, reach values up to 4.4, similar to the values obtained for hot pressing prepared materials. Further, it is demonstrated that tunnelling is the main mechanism responsible for the electrical response, independently of the preparation method of the material or the microstructural features. The large value of the gauge factor and the easy processing method demonstrates the suitability of these materials for cost effective and large-scale sensor applications. (C) 2016 Elsevier Ltd. All rights reserved.