Mussel-Inspired Adhesive and Tough Composite Hydrogel Based on Polydopamine-Modified Nanocellulose for Strain and Wireless Sensing

Adhesive composite hydrogels have received increasing attention in the fields of wearable sensors, electronic skin, and bioelectronic interfaces. However, combining good adhesiveness and high strength in a single composite hydrogel remains challenging. To address this issue, a polydopamine (PDA)-modified nanocellulose (PCNF)/polyacrylamide (PAM) composite hydrogel was developed, which exhibits good adhesiveness (40 kPa), good durability (1500 rpm), excellent frost resistance (-42 °C), and good sensitivity (GF = 1.6). The composite hydrogel exhibits self-healing and conductive properties, making it suitable for sensing and Morse code applications. The obtained composite hydrogels have potential applications in various wearable devices, wireless human computer interfaces, human activity monitoring, and remote encrypted transmissions.