MXene Nanoribbon-PEDOT:PSS Aerogel-Based Piezoresistive Sensors for Human Motion Detection and Thermal Insulation

Abstract

Piezoresistive sensors are widely used in strain and pressure sensors needed in a range of industrial, automotive, aerospace, consumer, and other applications. Aerogel-based sensors provide the advantages of lightweight, large contact area, and high sensitivity desired in practice. While silica, metal oxide, and metallic aerogel-based sensors demonstrate these advantages, wearable devices demand flexibility in addition to the above attributes, thus creating the need for investigating alternate materials. Here, we present a PDMS-coated MXene nanoribbon-PEDOT:PSS composite aerogel-based piezoresistive sensor and evaluate its performance in response to various body motions. The as-fabricated composite aerogel-based strain sensor exhibits a gauge factor of 2.63, which corresponds to a compressive strain of 14.9%. The sensing performance of the nanocomposite aerogel-based sensor is driven by the “disconnect–connect mechanism”, involving the breakdown and reformation of the conductive network in response to applied or released strain or pressure. Furthermore, the sensor exhibits hydrophobic properties, as demonstrated by a water contact angle of 113.8°. Interestingly, the sensor remains stable even after 2500 cycles of compression. In addition, the fabricated aerogel exhibits great potential as an effective thermal insulator. These results are important for the development of MXene aerogel-based lightweight and wearable sensors for health monitoring and other futuristic applications.