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Ti3C2T x 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 Ti3C2T x MXene/bamboo cellulose fiber (BCF)/poly­(dimethylsiloxane) (PDMS) composite pressure sensor with an ultrawide working range (up to 2 MPa), a high linearity (R 2 = 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.

Herein, a multifunctional polyurethane (PU) composite foam with a hierarchical structure is fabricated by dip-coating a carbon nanotube/shear-thickening gel (CNT/STG) and spray-coating nano-SiO 2 /STG on PU foam. The prepared nano-SiO 2 / CNT/STG@PU (SCS@PU) composite foam is lightweight, highly compressive, electrically conductive, superhydrophobic, and impact-energy absorptive. As a result, it possesses an excellent sensing ability to compression with a stable response up to 80% strain, an outstanding linearity of R 2 > 0.99, and a wide response frequency of 0.01 to 1 Hz; it can also be used for effectively detecting impact force and sensing various human motions. Moreover, the superhydrophobicity with a water contact angle up to 154°of SCS@PU composite foam endows it with an excellent resistance to hazardous liquids (strong acid and alkali) to ensure its service reliability under harsh circumstances. In particular, the SCS@PU exhibits an outstanding anti-impact capability with an impact force attenuation rate of SCS@PU as high as 81%. Finally, its applications as soft body armors are demonstrated in protecting a wearer wearing a helmet with the SCS@PU as liner and using the SCS@PU as a smart kneecap against impact. On consideration of its excellent strain-sensing ability, superhydrophobicity, and outstanding anti-impact capability, the multifunctional SCS@PU composite foam developed is promising for personal safety protection.

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