Flexible Energy Harvester on a Pacemaker Lead Using Multi-beam Piezoelectric Composite Thin Film.

Implantable medical devices, such as cardiac pacemakers and defibrillators, rely on batteries for operation. However, conventional batteries only last for a few years and need additional surgeries for replacement. Harvesting energy directly from the human body enables a new paradigm of self-sustainable power sources for implantable medical devices without being constrained by the battery's limited lifetime. Here, we report the design of a multi-beam cardiac energy harvester using PDMS-infilled microporous P(VDF-TrFE) composite film. We first added ZnO nanoparticles and multi-wall carbon nanotubes into microporous P(VDF-TrFE) films to increase the energy output. The mixing ratios of 30% ZnO and 0.1% MWCNTs yielded 3.22±0.24V output, which resulted in a voltage output 46 times higher than that of pure P(VDF-TrFE) films. Next, we discovered that the voltage generated by the composite film with PDMS is approximately 105% higher than that of the one without PDMS. For the application in cardiac pacemakers, we developed a facile fabrication method by building a cylindrical multi-beam device that resides on the pacemaker lead to harvest energy from the complex motion of the lead driven by the heartbeat. Since the energy harvesting component is integrated into the pacemaker, it significantly reduces the risks and expenses associated with pacemaker-related surgeries. This work paves the way towards the new generation of energy harvesters that will benefit patients with a variety of implantable biomedical devices.