Ultra-stretchable, antifreezing, and self-healing ZnO nanofluid-based hydrogels for triboelectric nanogenerators and self-powered biosensors

Flexible, self-healing, and highly sensitive wearable self-powered sensors are essential for promoting the rapid development of wearable electronics. Herein, a hydrogel based on zinc oxide nanofluids (AP-Zn) was synthesized using 2-acrylamido-2-methylpropane sulfonic acid and polyethylene glycol diacrylate. The AP-Zn hydrogel exhibits excellent stretchability (2750 %), high conductivity (1.37 S m−1), antifreezing capabilities (−20 °C), and self-healing abilities. Furthermore, the AP-Zn hydrogel was utilized to construct a triboelectric nanogenerator (AP-Zn-TENG), which demonstrated outstanding electrical output performance, with an open-circuit voltage, short-circuit current, and maximum power density of 135 V, 4.0 μA, and 1.39 W m−2, respectively. As a pressure sensor, the AP-Zn-TENG has a detection limit of 0.025 kPa and can even detect vocal cord vibrations of different pitches. Therefore, the AP-Zn-TENG self-powered sensor can be employed for detecting human behavior. These results suggest that the AP-Zn hydrogel holds great promise in wearable power technology and self-powered biosensors.