Water-proof and thermally inert flexible pressure sensors based on zero temperature coefficient of resistance hybrid films

The accurate measurement of pressure sensors realizes the idea of non-interference environmental monitoring, which is very important for the application of electronic skins (e-skins). Here, we designed a thermally inert flexible pressure sensor array based on a zero temperature coefficient of resistance (Z-TCR) hybrid film, consisting of multi-walled carbon nanotubes (MWCNTs) with a negative temperature coefficient (NTC) and graphite powders (GPs) with a positive temperature coefficient (PTC). In addition, to eliminate temperature interference, a water-proof effect can also be achieved by sealing the device in ethylene-vinyl acetate copolymer (EVA). The as-fabricated flexible pressure sensors exhibited excellent performances with ultrahigh sensitivity, fast response time, and good response stability at high frequency. The 5 × 5 pressure sensor array was also used for imaging spatial pressure distributions. The anti-environmental interference properties in combination with the excellent sensitivity, stability and extensibility show that the pressure sensor array has the potential for applications in e-skins.