This work presents a model for energy harvesting characterization of a simply supported beam with a mass in the middle to be used for powering pacemakers from heartbeat vibrations. The required power for a typical pacemaker is about 1.0 microwatts. A uniform cross-section beam, bimorph structures, employing double piezoelectric layers is used. PSI-5H4E piezoelectric and brass substrate is used in this study. Different configurations are utilized to identify the optimal design for lightweight energy harvesting devices with low-power applications to tune the natural frequencies of the energy harvester towards the operating ambient vibration source. In this paper, the exact analytical solution of the piezoelectric beam energy harvester with Euler–Bernoulli beam assumptions is presented. The energy harvester is intended to generate power from heartbeat induced vibrations to power implantable cardiac devices. The base excitations are thus heartbeat induced tissue vibrations. The proposed configuration harvests energy from the reverberation of heartbeats and converts it to electricity and could generate about 0.22 microwatts of power. Using the Fourier transform, the frequency response function for the voltage; current and power of the harvester are obtained. The power output for a range of values for the resistive load connected to the bimorph PZT layers is investigated to determine the optimized value of the resistive load that gives the maximum power output for the corresponding configuration of the beam. Stress analysis is performed for the substrate and PZT layer to make sure that the stress are within the permissible values to avoid breaking or failing of the beam. Results show that the use of mid mass is capable of harvesting a significant power with the proposed configurations.

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