Multifunctional Ag-PDA@PCM composite eutectogel based electronic skin for personal thermal management and a machine learning assisted wearable sensor.

Inspired by the perception and temperature regulation functionalities of human skin, multifunctional electronic skin (E-skin) for human motion detection and personal thermal management has attracted great attention. Here, we design an E-skin with strain sensing and personal thermal management capabilities based on a PAA-AgPPCM-x eutectogel, which was fabricated by introducing silver nanoparticle-deposited polydopamine-coated phase change microcapsules into an eutectogel matrix. The prepared eutectogel-based E-skin exhibits photothermal conversion, thermal energy storage and temperature regulation capabilities, and can effectively use solar energy for thermal management of the human body. Meanwhile, due the excellent mechanical properties and high conductivity of eutectogels, the eutectogel-based E-skin has the characteristics of a wide working range (0-400% strain), high sensitivity (highest gauge factor value is 5.13), fast response (239 ms) and recovery (337 ms), and excellent fatigue resistance (1000 cycles), and has successfully realized human motion detection, facial micro-expression recognition, and voice recognition. In addition, the eutectogel-based E-skin can be combined with machine learning algorithms to accurately classify 10 types of different complex gesture signals with high precision (97.0%). This multifunctional photothermal phase change microcapsule composite eutectogel-based E-skin shows great potential for application in intelligent wearable devices and personalized healthcare.