Piezoresistive Sensor Containing Lamellar MXene-Plant Fiber Sponge Obtained with Aqueous MXene Ink

ACS Appl Mater Interfaces. 2022 Nov 16;14(45):51361-51372. doi: 10.1021/acsami.2c15922. Epub 2022 Nov 6.

Abstract

Sustainable biomass materials are promising for low-cost wearable piezoresistive pressure sensors, but these devices are still produced with time-consuming manufacturing processes and normally display low sensitivity and poor mechanical stability at low-pressure regimes. Here, an aqueous MXene ink obtained by simply ball-milling is developed as a conductive modifier to fabricate the multiresponsive bidirectional bending actuator and compressible MXene-plant fiber sponge (MX-PFS) for durable and wearable pressure sensors. The MX-PFS is fabricated by physically foaming MXene ink and plant fibers. It possesses a lamellar porous structure composed of one-dimensional (1D) MXene-coated plant fibers and two-dimensional (2D) MXene nanosheets, which significantly improves the compression capacity and elasticity. Consequently, the encapsulated piezoresistive sensor (PRS) exhibits large compressible strain (60%), excellent mechanical durability (10 000 cycles), low detection limit (20 Pa), high sensitivity (435.06 kPa-1), and rapid response time (40 ms) for practical wearable applications.

Keywords: MXene; actuator; piezoresistive sensors; plant fiber sponge; wearable electronics.