In this paper the design and fabrication of an integrated micro energy harvester capable of harvesting electrical energy
from low amplitude mechanical vibrations is presented. A specific feature of the presented energy harvester is its
capability to harvest vibrational energy from different directions (3D). This is done through an innovative approach for
electrets placed on vertical sidewalls and thereby allowing for miniaturization of 3D capacitive energy harvester on
monolithic CMOS substrates. A new simple electret charging method using ionic hair-dryers/hair ionizers is reported and
shown that it can be effectively used for electrets-based micro energy harvesters.