A Flexible Tough Hydrovoltaic Coating for Wearable Sensing Electronics
Lianhui Li, Zhuo Zheng, Changlei Ge, Yongfeng Wang, Hao Dai, Lili Li, Shuqi Wang, Qiang Gao, Mengyuan Liu, Fuqin Sun, Ting Zhang
Abstract
Abstract The lack of a strong binding mechanism between nanomaterials severely restricts the advantages of the evaporation‐driven hydrovoltaic effect in wearable sensing electronics. It is a challenging task to observably improve the mechanical toughness and flexibility of hydrovoltaic devices to match the wearable demand without abandoning the nanostructures and surface function. Here, a flexible tough polyacrylonitrile/alumina (PAN/Al 2 O 3 ) hydrovoltaic coating with both good electricity generation (open‐circuit voltage, V oc ≈ 3.18 V) and sensitive ion sensing (2285 V M −1 for NaCl solutions in 10 −4 to 10 −3 m ) capabilities is developed. The porous nanostructure composed of Al 2 O 3 nanoparticles is firmly locked by the strong binding effect of PAN, giving a critical binding force 4 times that of Al 2 O 3 film to easily deal with 9.92 m s −1 strong water‐flow impact. Finally, skin‐tight and non‐contact device structures are proposed to achieve wearable multifunctional self‐powered sensing directly using sweat. The flexible tough PAN/Al 2 O 3 hydrovoltaic coating breaks through the mechanical brittleness limitation and broadens the applications of the evaporation‐induced hydrovoltaic effect in self‐powered wearable sensing electronics.