Process Development of Piezoelectric Micro Power Generator for Implantable Biomedical Devices

Piezoelectric micro-power generator (PMPG) converts mechanical vibration energy into electric energy from human body via piezoelectric effects. In cardiac pacemakers, the use of PMPG eliminates the need for a traditional lithium iodide battery replacement. This paper covers fabrication process development of PMPG that is able to harvest the human body mechanical vibration to be converted into usable electrical power in low frequency range (1-100) Hz. The PMPG device developed has 10 μm SU8 proof mass, 200nm Au /20 nm Cr interdigitated electrode, 1.5 μm functioning PZT layer and 200 nm Si3N4 on 10 μm Si substrate. The Fabricated PMPG vibrate at 61 Hz with power density of 0.29 W/cm3 and can supply 3.33AC voltage, 2.19V DC voltage to the final load. The PMPG is suitable to power most of small electronic devices including cardiac pacemaker at frequency below 100 Hz.