Stable, Breathable, and Self-Supporting Electronic Skin for Human Physiological Signal Monitoring

Abstract

Electronic skin has broad application prospects in wearable electronics, human–computer interaction, and biomedical fields due to its conductive, conformable, breathable, and stretchable properties. However, flexible-substrate electronic skin hinders breathability due to the high density of polymer materials and substrate-free structures, and it is prone to breakage due to insufficient mechanical constraints, limiting long-term wearing reliability. This article proposes an electric field-driven micro-3D printing electroplating collaborative strategy to construct a fully wrapped core–shell self-supporting metal mesh electronic skin that is substrate-free, highly breathable, and highly stable. The flexibility and high-resolution deposition capability of electric field-driven micro-3D printing technology have enabled the preparation of a fine-scale silver paste conductive network, and the integration with electroplating technology enhances the conductivity of the silver paste conductive network and provides omnidirectional support and protection, making it exceptionally stable. At the same time, the substrate-free low fill factor (500 nm wavelength, transmittance of 97.2%) design achieves high breathability, no stuffiness or discomfort when worn, and a stable structure after soaking/rinsing. Experimental results demonstrate that the resistance of a grid with a line spacing of 0.6 mm only changes by 5.5% after 1000 bends with a radius of 4.5 mm, and the resistance change rate in an alkaline environment after 72 h is 7.67%. It was further applied to facial smile recognition and wrist/knee movement monitoring, achieving high-fidelity physiological signal acquisition and solving the measurement error problem of traditional device contact decoupling. This work overcomes the bottleneck of balancing breathability and stability in electronic skins, providing ideas for the design of high-performance wearable electronic skins.