Flexible Antiswelling Photothermal-Therapy MXene Hydrogel-Based Epidermal Sensor for Intelligent Human–Machine Interfacing

Conductive hydrogel-based epidermal sensors are regarded with broad prospects in bridging the gap between human and machine for personalized healthcare. However, it is still challenging to simultaneously achieve high sensitivity, wide sensing range, and reliable cycling stability in hydrogel-based epidermal sensors for ultrasensitive human–machine interfacing, along with brilliant antiswelling capability, and near-infrared (NIR) light-triggered dissociation and drug release for further smart on-demand photothermal therapy. Herein, the facile preparation of a flexible multifunctional epidermal sensor from the elaborately fabricated, highly stretchable, and antiswelling MXene hydrogel is presented. It exhibits high sensitivity, wide sensing range (up to 350% strain), and reliable reproducibility for enabling ultrasensitive human-machine interfacing. It displays excellent antiswelling capability for the hydrogel to avoid expanding the wound due to excessive swelling for further reliable wound therapy. Furthermore, it possesses good biocompatibility and robust photothermal performance for the smart photothermal therapy after healthcare monitoring. Meanwhile, the sensor can be triggered to be softened and partly dissociated under the prolonged NIR light irradiation with the transformation of the temperature-sensitive low-melting-point Agar into a sol state and the partial dissociation in the hydrogel to release the loaded drug on demand for synergistically sterilizing bacteria and efficiently promoting wound healing.