Implanted Battery-Free Direct-Current Micro-Power Supply from in vivo Breath Energy Harvesting

摘要

In vivo biomechanical energy harvesting by implanted nanogenerators (i-NG) is promising for self-powered implantable medical devices (IMDs). One critical challenge to reach practical applications is the requirement of continuous direct-current (DC) output, while the low-frequency body activities typically generate discrete electrical pulses. Here, we developed an ultra-stretchable micro-grating i-NG system that could function as a battery-free DC micro-power supply. Packaged by a soft silicone elastomer with a cavity design, the i-NG exhibited an ultralow Young’s modulus of ~45 kPa and a high biocompatibility to soft biological tissues. The i-NG was implanted inside the abdominal cavity of Sprague Dawley (SD) adult rats, and directly converted the slow diaphragm movement during normal respiration into a high-frequency alternative current (AC) electrical output, which were readily transmitted into a continuous ~2.2 V DC output after being integrated with a basic electrical circuit. A LED was constantly operated by the breath-driven i-NG without the aid of any battery component. This solely biomechanical energy-driven DC micro-power supply offers a promising solution for the development of self-powered IMDs.