Project Summary: Revolutionary advancements in pacemakers include a miniaturized and leadless design and intracardiac implantation. However, the bulky and rigid battery creates the largest hurdle towards further development of a soft system that can be attached and conform to tissue and muscle surfaces without causing unwanted physiologic changes. To address this critical challenge, this project proposes to develop a self-sustainable power source (SSPS) for intracardiac pacemakers using swine models. The SSPS integrates a stretchable, frequency-tuning implantable nanogenerator (i-NG) with a miniaturized supercapacitor and regulating electronics, which can automatically and consistently power a pacemaker by harvesting energy from heartbeats. This project is led by Dr. Wang (PI), with Drs. Hacker and Liu as the co-Is and a cardiac surgeon Dr. Osaki as collaborator, for the development of a flexible i-NG to harvest energy from biomechanical sources. Previous work from Wang and Hacker has confirmed the long-term stability of i-NGs and their negligible impacts on normal heart functions when sutured on swine hearts. Wang has also developed a flexible, micro-grating i-NG capable of converting slow organ motion to continuous alternating current (AC) electricity desired for efficient capacitor charging. Building on these supportive preliminary results, this project focuses on designing and validating a SSPS specifically for powering intracardiac pacemakers by harvesting energy from heartbeats. In Specific Aim 1, we will develop a stretchable SSPS that integrates a flexible i-NG with a commercial supercapacitor and regulating electronics. The membrane i-NG can convert heart beats into continuous, high-frequency AC electricity with an output voltage suitable for efficiently charging the supercapacitor. In Specific Aim 2, we will investigate the bio- and hemo-compatibility of SSPS ex vivo and test the SSPS device in a simulated intracardiac environment. In Specific Aim 3, we will characterize electrical output of SSPS in vivo epicardially in different locations and orientations on the epicardial surface of the right ventricle (RV) of swine hearts. Cardiac function will be monitored over time to ensure SSPS implantation does not alter heart function. The ability to power a commercial pacemaker will also be tested in vivo. In Specific Aim 4, we will investigate intracardiac implantation of SSPS on the internal RV free wall of a surgically removed and beating swine heart on a Langendroff apparatus to test the intracardiac operation ex vivo. This proposed research will develop a novel intracardiac energy harvester that is self-sustainable by harvesting biomechanical energy from heartbeats. Success of this research will establish a technology framework necessary to move rapidly to in vivo intracardiac implantation and testing of SSPS for powering intracardiac pacemakers . This intracardiac energy harvesting technique will present an unprecedented engineering s...