Stretch-insensitive capacitive pressure sensor based on highly stretchable CuNWs electrode

Abstract

Flexible pressure sensors have been widely studied due to the increasing interest in wearable devices, intelligent skin, and hyperthermia equipment. However, it is still challenging to apply the sensors to practical wearable applications, because their sensing performance is subject to change and degraded when the sensor is stretched. Herein, we report a stretching-insensitive capacitive pressure sensor (SICPS) with high sensitivity. This is obtained by developing a highly stretchable electrode composed of copper nanowires (Cu NWs) networks and wrinkled polydimethylsiloxane (PDMS) elastic film. The prepared sensors show a pressure sensitivity of 0.162 kPa −1 in a pressure range up to 6 kPa. The SICPS can maintain a good performance in the stretched state (below 200% of strain). More importantly, the SICPS achieves an excellent insensitivity to the stretching within a strain of 80%, the change of sensitive factor is below 0.8%. These enable the demonstration of stretchable and resilient on-skin strain sensors capable of monitoring the motions of the human. • Stretching-insensitive capacitive pressure sensor is prepared successfully. • The change of sensitivity is below 0.8% even stretched up to a strain of 80%. • The sensor still works steadily in the stretched state (below stain of 200%).