Antifreeze protein-based ultrastretchable and highly sensitive hydrogel for human-machine interaction

Intelligent and convenient human–computer interfaces realize efficient and close cooperation between people and the digital world. As windows of human–machine interaction (HMI), sensors directly determine the ability and quality of acquired signals and the utilization potential of HMI systems. However, it still remains challenging to develop antifreeze hydrogel sensors with freeze-resistant properties while avoiding the loss of other properties as much as possible to achieve stable HMI applications in low-temperature environments. Here, we present an Agar/PAAm dual-network hydrogel (Na+-Agar/PAAm-AFP) doped with both antifreeze protein (AFP) and sodium chloride (NaCl), which exhibits excellent antifreeze capability (−20 °C). The hydrogel integrates transparency (>90 %), ultra stretchability (up to 2100 %), good adhesion properties to metal, glass, and plastic, high electrical conductivity (3.41 S m−1), high sensitivity (GF = 10.23), and non-irritating to the skin. The hydrogel can be used for monitoring daily activities and glove-based HMI systems for intelligent control. In addition, based on this hydrogel, we have successfully developed an interactive system for real-time information transfer over long distances. It is expected to provide better health management monitoring in several fields and also help to advance the development of innovative and IoT technologies.