A low-frequency piezoelectric energy harvester based on impact vibration assembled with a compliant
driving beam and two rigid generating beams is presented.The ambient low frequency is up-converted to
high resonant frequency by the periodic impact between the driving beam and the generating beams.The
advantages of the harvester are:restricting the large displacement of the compliant driving beam,improving power density and being especially suitable for ac ompact MEMS approach.The 1.53mW
average power of the macroscale impact vibration harvester is achieved at 20.1Hz under 0.4 g
improving power density and being especially suitable for a compact MEMS approach.The 1.53mW
average power ofthemacroscaleimpactvibrationharvesterisachievedat20.1Hzunder0.4g
acceleration.The power density is 93.2 mW /cm3, which is 6.8times that of conventional counterpart
(13.6 mW/cm3). Themeasuredresultsdemonstratethepotentialofthedeviceappliedtoportableand