Biomimetic breathable nanofiber electronic skins with temperature-controlled self-adhesive and directional moisture-wicking properties for bifunctional pressure and non-contact sensing

Electronic skin has fast developed in recent years for its promising application in wearable sensing. Multifunction of breathability, self-adhesion, sweat release and diverse sensing is highly required but has not been achieved on a single device. Herein, inspired by natural human skin, we develop a breathable and self-adhesive electronic skin based on an all-nanofiber platform with unique directional moisture-wicking properties and bifunctional pressure and non-contact sensing capability. The multifunctional device is integrated with four functional parts self-adhesive gel, moisture-wicking structure, pressure sensing layer and non-contact detection layer. Benefits from structural design and advanced sensing principles, the sensor not only demonstrates high pressure-sensing sensitivity of 23 kPa-1 and ultrawide non-contact detection range of 2 m but also exhibits excellent breathability of 53.9 mm s-1 and fast moisture-wicking ability. Interestingly, the sensor can be tightly attached to human skin at skin temperature and be easily peeled off at elevated temperatures by using the temperature-controlled reversible phase-transition gel. Towards practical wearable sensing applications, different movements can be identified with 97.3% accuracy by using the four-layer Multi-Layer Perceptron neural network. This work will boost the development of next-generation multifunctional electronic skins with both wearing comfortability and diverse sensing capability.