Conductive MXene/cotton fabric based pressure sensor with both high sensitivity and wide sensing range for human motion detection and E-skin

Abstract

• Conductive MXene coated cotton fabric is prepared for wearable pressure sensor. • The pressure sensor shows both high sensitivity and broad sensing range. • The porous and sandwiched architecture accounts for the good sensing property. • The pressure sensor has great potential for human motion detection and E-skin. Flexible wearable pressure sensors have attracted tremendous interest for applications in human health monitoring, electronic skin, artificial intelligence and so on. However, it is still a critical challenge for pressure sensors to simultaneously achieve high sensitivity and wide sensing range while performing well in response time, stability, reliability and wearing comfortability. Here, conductive MXene/cotton fabric was fabricated using the simple dip-coating technique and then sandwiched between polydimethylsiloxane film and an interdigitated electrode for flexible wearable piezoresistive pressure sensor. The abundant hydroxyl groups of cotton fabric and functional groups of MXene were beneficial for the good adhesion of conductive MXene nanosheets onto the entangled fiber networks, constructing effective conductive network. Taking advantage of the excellent flexibility and three-dimensional porous structure of cotton fabric and the special sandwich architecture of the sensor, the MXene/cotton fabric (MCF) based pressure sensor exhibited high sensitivity (5.30 kPa −1 in the pressure range of 0–1.30 kPa), broad sensing range (0–160 kPa), rapid response/recovery time (50 ms/20 ms), excellent stability and long-term durability. Moreover, the MCF based pressure sensor can be employed to detect and distinguish various human health signals, including finger motion, early stage Parkinson’s static tremor and wrist pulse. Importantly, E-skin was also designed based on the MCF based pressure sensor for the recognition of different tactile stimuli, exhibiting promising potential in next generation wearable electronics.