A piezoelectric vibration energy harvester was investigated to generate the electricity from twodimensional
ambient vibrations (less than 1g and 60Hz) for mobile handsets, building automation, medical, and
defense applications. The proposed energy harvester was designed and fabricated by using a bimorph PZT (lead
zirconate titanate) bender and an inertial mass. In order to harvest the two dimensional vibrations, the fabricated
inertial mass was asymmetrically assembled at the end of the PZT bender by adjusting the center of mass. The
asymmetric inertial mass contributes to generate power from the vibration applied into the length direction of PZT
bender. The fabricated device generated 7.5 mW and 1.4 mW of electrical power from the induced vibration
through the thickness and length direction of PZT bender, respectively.