Penguin Skin-Inspired, Nanoparticle-Reinforced Hydrogels for Extreme Environment-Resistant Piezoionic Generation and Sensing

Most hydrogels rely heavily on cryoprotectants to enhance their anti-freezing capabilities; however, this approach is often accompanied by disadvantages such as altered network structures and the risk of cryoprotectant leakage in aqueous conditions. Given these challenges, an environmentally resilient diode-like hydrogel is developed, featuring a double-layer coating design inspired by the physiological characteristics of penguins. This design is achieved through plasma treatment and immersion in 3-aminopropyltriethoxysilane/butyl acetate and perfluoropolyether carboxylic acid/butyl acetate solutions, constructing a double-layer coating with stable interfacial strength. The coating not only enhances anti-dehydration performance but also imparts anti-freezing properties via N,N-dimethylformamide solution. By carefully regulating the coating thickness and polymerization duration, it has optimized the mechanical and electrical attributes of hydrogel, culminating in robust performance even at −80 °C. The hydrogel exhibits exceptional water retention capabilities, with a mere 33.4% water loss rate following 7 days of air drying. Moreover, the hydrogel demonstrates stable piezoionic output performance across various low-temperature environments, with tensile and compressive strengths of 1156 kPa and 3.45 MPa, respectively. This study presents a novel solution for the application of conductive hydrogels in smart wearable devices, underscoring their potential for use in extreme environments.