Flexible triboelectric hydrogels for underwater communication and implant devices

Flexible high-frequency vibration sensors are widely used in marine acoustic energy harvesting, implantable medical devices, and underwater ultrasonic communication systems. This paper presents the design of a flexible triboelectroacoustic device. Microstructures on the hydrogel surface are designed to optimize stress distribution within the device. Furthermore, we compare the effect of different glycerin (Gy) ratios in the hydrogel on peak voltage under constant conditions. Experimental results show that the device exhibits optimal output performance with a glycerol content of 28.07 %, accompanied by an ideal Young's modulus. A sample prepared with this formula can reach a voltage of 4.5 V within 10 seconds at a sound pressure of 0.9 MPa. During the exploration of underwater communication potential, ultrasonic devices use "0" and "1" modulation with the ASCII binary table as the encoding strategy for information transmission. The final results show that the demodulated output signal matches the input signal exactly. To further evaluate the performance of the device as an implantable energy harvester, it was implanted into pork tissue at a subcutaneous depth ranging from 1 cm to 4 cm. The results indicate that the device can charge a 470µF capacitor to 0.5 V in 10 seconds. This research offers promising prospects for the development of intelligent and lightweight implantable devices.