Highly efficient piezoelectric micro harvester for low level of acceleration fabricated with a CMOS compatible process

This paper reports new results of fabrication and characterization of piezoelectric micro-harvesters designed for a frequency of 200Hz and very low input accelerations. We developed a process fully CMOS compatible with AlN (Aluminum Nitride) piezoelectric harvesters. We present a device working very efficiently at very low levels of acceleration. This device allows us to harvest 0.62μW at 214 Hz for 0.17g RMS for a volume of less than 3mm³. Under vacuum, the power harvested is more than doubled. Compared to literature, this device presents, under vacuum, the best figure of merit.