Wearable thermoelectric-powered textile-based temperature and pressure dual-mode sensor arrays

Flexible thermoelectric-powered textile-based temperature and pressure dual-mode sensors (TET-TPDS) show promises in wearable electronic skin because of the merit of lightweight, three-dimensional conformability and breathability. However, the sensitivity is relatively low because of the low integration density of TE segments. In this work, we report a three-dimensional TET-TPDS array by sewing polyethyleneimine (PEI) segmentally doped carbon nanotube yarn into a spacer fabric with large arrangement density of TE segments (~11-12 pairs/cm2). The TET-TPDS array can detect temperature and pressure accurately and show high temperature and pressure sensitivity of 0.87 mV/K and 0.312 kPa-1 in the low-pressure region (0-1.2 kPa), standing out in the thermoelectric-powered temperature sensors and spacer fabric-based pressure sensors. The high temperature and pressure sensitivity result from the high Seebeck coefficient of the TET-TPDS array and the sensitive pressureinduced thermal resistance change between TE segments and stimuli. More importantly, the TET-TPDS array can be used repeatedly under the pressure of <9 kPa because the spacer fabric is elastically deformed in this region. Finally, we demonstrate the practical application of the sensor array to detect external stimuli. It presents accurate spatial distribution mapping and fast response time, which shows great potential in large-area electronic skin towards on-body healthcare monitoring applications.