Abstract

Due to the increased demand for wearable devices, there has been extensive research on flexible energy storage devices (e.g., batteries and supercapacitors) and bio-signal monitoring sensors. For the practical application of wearable devices, stable operation regardless of the environmental temperature is required. In this study, we report a temperature-tolerant flexible supercapacitor based on a synthesized novel organohydrogel electrolyte designed to power an integrated strain sensor for the monitoring of bio-signals. The fabricated supercapacitor exhibits a remarkable gravimetric capacitance of 123.4F g−1, 147.0F g−1, and 156.2F g−1 at temperatures of − 20 °C, 25 °C, and 80 °C, respectively. After three repetitive cycles shifting from − 20 °C to 80 °C, the initial capacitance is almost fully recovered. In addition, after 1000 cycles of bending deformation, the capacitance remains almost the same, thus verifying the flexibility of the device. A strain sensor fabricated using the same organohydrogel exhibits a change in resistance with stretching deformation, with a gauge factor of 1.77, 1.61, and 1.50 at 25 °C, −20 °C, and 80 °C. By vertically integrating the supercapacitor and strain sensor, various bio-signals, including finger bending and swallowing are successfully detected using the stored energy of the supercapacitor. As a whole, the results highlight the potential of our proposed temperature-tolerant flexible device fabricated based on a single organohydrogel for use in wearable applications that are stable over a wide range of environmental temperatures.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call