A Comparative Numerical Study on Piezoelectric Energy Harvester for Self‐Powered Pacemaker Application

This study proposes the design of a micro‐spiral‐shaped piezoelectric energy harvester that scavenges energy from blood pressure variation in the cardiac cycle. The harvester can be a miniaturized perennial source of power that could even eliminate the need for replacement of conventional batteries used in current pacemaker technology. The concept of a 25 µm thin spiral‐based piezoelectric energy harvester with a diameter of 6 mm satisfying the dimensional constraints has been proposed. A number of lead‐free materials have been used along with Pb[Zr(x)Ti(1−) (x)]O(3) (PZT‐5A) to compare the performance. The harvester has been designed in such a way that the natural frequency of the structure remains in the range of 1.1–1.3 Hz, which is equivalent to 66–78 heart beats min(−1) of humans. The obtained alternating electric current from piezoelectric materials is converted into direct current. The maximum open‐circuit voltage obtained is ≈0.9 V, which is not sufficient for charging a pacemaker battery. Therefore, boost converter circuit is employed to step up the voltage. It is found that K(0.475)Na(0.475)Li(0.05)(Nb(0.92)Ta(0.05)Sb(0.03))O(3) (KNLNTS) has the best performance as compared to other materials under study. The boosted voltage obtained from KNLNTS is ≈6 and ≈7 V for 80 and 90% duty cycle, respectively, which are sufficient for pacemaker battery charging.