Mixed-Dimensional MXene Nanocomposites/Aramid Nanofibers-Based Flexible Pressure and Strain Sensor for Electronic Skin

The implementation of tactile functions in array sensors has created an urgent need for high-performance force sensors with both high linearity and sensitivity so as to ensure the uniformity and accuracy of acquisition of multiple sensing units in the array sensors. In addition, it still remains challenging to fabricate exquisite geometric constructions for integrating highly sensitive materials, extraordinary sensitivity, high stretchability, wide sensing range, and flexibility into a single type of pressure/strain sensor. Herein, a sensitive flexible sensor was fabricated that was composed of mixed-dimensional MXene-based nanocomposites as piezoresistive layers and Ecoflex layers as the encapsulation. The resultant sensors with MXene (Ti3C2Tx)-ANF (aramid nanofiber)-BP (black phosphorus)-gold (Au) nanocomposites exhibited excellent electrical conductivity, ultrahigh press sensitivity of 0.4986 kPa–1 (0–1 kPa), reliable linearity (R2 = 0.998), rapid response time of 12 ms, excellent durability over 4000 cycles, and ultrahigh tensile sensitivity of 9188.583. An 8 × 8 pixel electronic skin was fabricated by the as-prepared mixed-dimensional MXene-based sensors and tested in the identification of sliding movements and surface shape, and the good performance shows great potential applications in the fields of wearable devices, human–machine interaction, and robotics.