Flexible pressure sensor based on Pt/PI network with high sensitivity and high thermal resistance

The increasing development of wearable electronics necessitates the urgent need for highly sensitive flexible pressure sensors suitable for harsh environments at high/low temperatures, thus meeting the specific requirements of wilderness survival, lunar exploration, mine exploration, and so on. Herein, a flexible piezoresistive sensor based on 3D Pt/PI fibrous network is prepared through the electrospinning and ion-sputtering techniques, demonstrating excellent sensing performance over a wide temperature range from liquid nitrogen temperature to 250 °C. The 3D Pt/PI pressure sensor achieves high sensitivity of 158.23 kPa−1 at room temperature, and remains remarkable sensitivity of 71.47 kPa−1 and 7.63 kPa−1 at 150 °C and 250 °C, respectively. Furthermore, benefiting from the hydrophobicity of the Pt/PI fibrous network, the sensitivity of the pressure sensor stabilizes in about 148 ± 10 kPa−1 under relative humidity from 30 % to 90 %, indicating humidity-independent sensing performance. As a proof of concept, the fabricated piezoresistive sensor can be not only monitor the human physiological information in real-time, but also detect external mechanical stimuli at high/low temperatures, demonstrating great potential for application in harsh environments.