Embedded piezoelectric energy harvesting (PEH) systems in medical pacemakers have been an attractive and well visited research area. These systems typically utilize different configurations of beam structures with forcing originating from heart beat oscillations. The goal of these systems is to remove the pacemaker battery, which makes up 60–80% of the device volume, and replace it with a self-reliant power option. With emerging technologies encouraging a push towards leadless pacemakers typical energy harvesting beam structures are becoming inherently coupled with the heart system. The introduction of the nonlinearity resulting from the bistable magnetic interaction of two magnets is known to enhance energy harvesting performance due to its double-well potential behavior. Introducing the elastic magnifier enables large tip oscillations and high energy orbits for the bistable system. A continuous nonlinear model is derived for the bistable system (BPEH) and a one-degree-of-freedom linear mass-spring-damper model is derived for the elastic magnifier. The elastic magnifier (EM) will not consider the damping negligible due to the viscous nature of the heart, unlike most models. For experimental testing a physical model was created for the bistable structure and fashioned to an elastic magnifier. A hydrogel was chosen as the physical model for the EM. Experimental results have shown that the bistable piezoelectric energy harvester coupled with a linear elastic magnifier (BPEH+LEM) produces more power at certain input frequencies and operates a larger bandwidth than a PEH, BPEH, and a standard piezoelectric energy harvester with the elastic magnifier (PEH+LEM). Numerical simulations were validated by these results showing that this system enters high-energy and high orbit oscillations. It has been shown that BPEH systems implemented in medical pacemakers can have enhanced performance if positioned over the myocardial heart wall.

Embedded piezoelectric energy harvesting (PEH) systems in medical pacemakers have been a growing and innovative research area. The goal of these systems, at present, is to remove the pacemaker battery, which makes up 60%–80% of the unit, and replace it with a sustainable power source. This requires that energy harvesting systems provide sufficient power, 1–3 μW, for operating a pacemaker. The goal of this work is to develop, test, and simulate cantilevered energy harvesters with a linear elastic magnifier (LEM). This research hopes to provide insight into the interaction between pacemaker energy harvesters and the heart. By introducing the elastic magnifier into linear and nonlinear systems oscillations of the tip are encouraged into high energy orbits and large tip deflections. A continuous nonlinear model is presented for the bistable piezoelectric energy harvesting (BPEH) system and a one-degree-of-freedom linear mass-spring-damper model is presented for the elastic magnifier. The elastic magnifier will not consider the damping negligible, unlike most models. A physical model was created for the bistable structure and formed to an elastic magnifier. A hydrogel was designed for the experimental model for the LEM. Experimental results show that the BPEH coupled with a LEM (BPEH + LEM) produces more power at certain input frequencies and operates a larger bandwidth than a PEH, BPEH, and a standard piezoelectric energy harvester with the elastic magnifier (PEH + LEM). Numerical simulations are consistent with these results. It was observed that the system enters high-energy and high orbit oscillations and that, ultimately, BPEH systems implemented in medical pacemakers can, if designed properly, have enhanced performance if positioned over the heart.