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

Area of Science:

• Biomedical Engineering
• Materials Science
• Energy Harvesting

Background:

• Pacemaker technology relies on conventional batteries requiring replacement.
• Miniaturized, perennial power sources are needed to improve pacemaker longevity and reduce patient burden.

Purpose of the Study:

• To design and evaluate a micro-spiral piezoelectric energy harvester (PEH) for scavenging energy from cardiac cycle blood pressure variations.
• To assess the suitability of various lead-free piezoelectric materials for this application.
• To achieve sufficient voltage output for pacemaker battery charging.

Main Methods:

• Design of a 25 µm thin, 6 mm diameter spiral-based PEH.
• Comparison of lead-free materials, including K0.475Na0.475Li0.05(Nb0.92Ta0.05Sb0.03)O3 (KNLNTS) and Pb[ZrTi]O3 (PZT-5A).
• Integration of a boost converter circuit to increase the harvested voltage.

Main Results:

• The harvester's natural frequency was tuned to the human heart rate (1.1-1.3 Hz).
• The KNLNTS material demonstrated superior performance compared to other tested materials.
• Boosted voltages of approximately 6-7 V were achieved with KNLNTS, sufficient for pacemaker charging.

Conclusions:

• The micro-spiral PEH is a viable concept for a self-sustaining pacemaker power source.
• KNLNTS is a promising lead-free material for piezoelectric energy harvesting in biomedical applications.
• The developed system effectively converts mechanical energy from blood pressure variations into usable electrical energy for pacemakers.