Highly Sensitive, Self-Healable, and Robust Polyvinyl Alcohol/Nanocellulose Composite Electronic Skin by Single-Step Marangoni Self-Assembly for Multipoint Sensing

The polyvinyl alcohol (PVA)-based electronic skin with skin-like features and functions has shown great promise in wearable electronics, but traditional physical methods do not provide multiple interfacial bonds to result in poor mechanical properties, weak conductivity, low sensitivity, and healing ability for further hindering their practical application. In this work, novel alternating spraying technology driven by the Marangoni effect was used to address this challenge and took advantage of the interfacial bond and compatibility between nanocellulose-polyaniline (CNC-PANI) and PVA/CNC films to prepare self-assembled PVA/nanocellulose polyaniline (PVA/CP) electronic skin. Among them, the optimal PVA/CP electronic skin exhibited excellent mechanical performances (stress up to 78.2 MPa), large conductivity (648 mS/m), and high sensitivity (gauge factor = 22.7) with good self-healing abilities (healing efficiency 73.5%). Furthermore, it was designed and integrated into a multi-point sensing system for non-overlapping Morse code communication and real-time monitoring of human health during fitness exercise. Therefore, such high-performance PVA/CP electronic skin is expected to play a demonstration role in a new generation of sustainable wearable electronics.