Transparent self-powered triboelectric sensor based on PVA/PA hydrogel for promoting human-machine interaction in nursing and patient safety

Human-machine interaction (HMI) has made great progress in the intelligent medical system, realizing the interaction between patients, medical staff and medical equipment. Here, we report a triboelectric nanogenerator with the flexible-stretchable polyvinyl alcohol/phytic acid (PVA/PA) hydrogel for self-powered HMI sensing in intelligent medical system. Benefiting from effective optimization design of materials, it possesses excellent mechanical and electrical properties, such as over 20,000 cycles durability, transparency, flexibility, and power density up to 1.33 W·m−2. The device has a linearity of up to 0.949 in the tensile range of 200% and 0.992 in the bending angle range from 30° to 90°, respectively. Through processing and encoding the electrical signals collected by multiple channels in independent or synergistic mode, a self-powered medical nursing HMI system attached to patient fingers was developed to provide real-time help and assistance for both patients and medical staff, which the demand for distress calls can be successfully transmitted with just gently bending fingers in diagnosis. This work exhibits the application value of the self-powered triboelectric sensor to the medical HMI field, and can be extended to other aspects, showing a broad impact in brain computer interface.