Apr 8, 2025
10:30am - 11:00am
Summit, Level 4, Room 437
Sang-Woo Kim1
Yonsei University1
Implantable medical devices (IMDs) are designed to perform or augment the functions of existing organs by using monitoring, measuring, processing units, and the actuation control. Conventional IMDs are powered with primary batteries that require frequent surgeries for maintenance and replacement. Therefore, IMDs require a new reliable and safe powering system to avoid the need for frequent surgeries. In addition, hermetically sealed titanium (Ti) packaging provides protection for implantable medical devices, while it hinders reliable wireless power transfer to these devices. We present a miniaturized device that utilizes ultrasound-induced vibrations in Ti, mediated by liquid space, for efficient triboelectric energy harvesting. Unlike the conventional ultrasound-driven triboelectric nanogenerator inducing contact electrification through multiple modes, the Ti-packaged device generates vibrations of the triboelectric membrane in a single mode, facilitating effective energy transfer. The incorporation of the Ti packaging leads to a significant increase in power density, up to 310% compared to the absence of it when measured under a tissue-mimicking material, and it enables long-term stability and Bluetooth communication in vivo. These findings represent the first technology that enhances power transmission characteristics through a Ti layer.