Ti3C2Tx MXene/Bamboo Fiber/PDMS Pressure Sensor with Simultaneous Ultrawide Linear Sensing Range, Superb Environmental Stability, and Excellent Biocompatibility

Abstract

Ti3C2Tx MXene has drawn remarkable attention in electronic sensors. Existing MXene-based pressure sensors generally have a narrow linear sensing range, which limits their wide application. Moreover, previous studies on MXene-based pressure sensors were mainly focused on increasing sensitivity via various microengineering techniques, but little attention has been paid to environmental stability and biocompatibility of these sensors. Herein, a highly flexible, biocompatible, and environmentally stable Ti3C2Tx MXene/bamboo cellulose fiber (BCF)/poly(dimethylsiloxane) (PDMS) composite pressure sensor with an ultrawide working range (up to 2 MPa), a high linearity (R2 = 0.966), and long-term stability is demonstrated. First, the MXene/BCF (MB) foam with well-optimized porosity and connectivity was prepared through an efficient freeze-drying method. Then, the MB-based piezoresistive composite (PMB) was obtained by directly embedding the MB foams into PDMS elastomers. In striking contrast to previous MXene composite-based pressure sensors, the PMB pressure sensor exhibits not only excellent pressure sensing performance and good biocompatibility but also prominent work reliability to resist temperature fluctuation, moisture/water, and UV irradiation. Furthermore, to demonstrate the potential of the PMB pressure sensor, various human movements under both ambient and harsh environmental conditions were monitored. Finally, the PMB pressure sensor was also successfully integrated with soft robotic hands to show its great potential in robotic tactile sensation.