Aloe Inspired Special Structure Hydrogel Pressure Sensor for Real-Time Human-Computer Interaction and Muscle Rehabilitation System

In recent years, significant progress has been made in the research and development of conventional hydrogel sensors. However, the development of hydrogels with special structures, achieved through specific designs or fabrication strategies, remains relatively scarce. Inspired by aloe, a specially structured hydrogel (named Skin-Polyvinyl alcohol-Polyaniline-AgNWs, S-PPA) is successfully prepared with skin. Innovatively utilizing the hydrogen bonding interaction between ions and water molecules, the surface of the hydrogel is treated to create a protective skin. The S-PPA hydrogel with a protective skin demonstrates strong resistance to damage (with a tensile strength of 5 MPa, >11 times higher compared to hydrogel without skin) and exhibits dual conductivity (0.8 S m(-1) for the inner skin and 0.33 S m(-1) for the outer skin). In addition, the S-PPA hydrogel also possesses water retention capabilities, antibacterial properties (89.4% inhibition rate against Staphylococcus aureus (S. aureus)), and minimal corrosion to metal electrodes. Based on the S-PPA hydrogel and combined with wireless Bluetooth technology and Python programming, intelligent applications are developed such as multi-gradient intelligent control and finger muscle condition evaluation, achieving real-time human- computer interaction (HCI). The intelligent pressure-sensitive hydrogel proposed by this study shows great potential in the fields of medical rehabilitation, artificial intelligence, and the Internet of Things.