Self-Energy Harvesting Pacemakers: An Example of Symbiotic Synthetic Biology

While synthetic biology has traditionally focused on creating or redesigning biological systems often through genetic engineering, emerging technologies, for example, implantable pacemakers with integrated piezo-electric and tribo-electric materials are beginning to enlarge the classical domain into what we call symbiotic synthetic biology. These devices permanently attached within a body, although non-living or genetically unaltered, closely mimic biological behavior by harvesting biomechanical energy and providing functions such as autonomous heart pacing. They form active interfaces with human tissues and operate as hybrid systems, similar to synthetic organs. The present paper first presents a short summary of previous in vivo studies on piezo-electric composites devoted to battery-less pacemakers and then summarizes a recent theoretical work using a damped harmonic resonance model to mimic the working of such devices. We then extend the theoretical study further to include new solutions & obtain a sum rule for the power output per cycle in such systems. Lastly, a novel proposal is made to explore the modulation of the quantum vacuum energy (Casimir effect) by periodic body movements to power pacemakers.