An energy harvester comprising a base; one or more first resilient means mounted on the base; a hollow chamber having a mounting point pivotally attached to the first resilient means; a hollow member enclosed within the hollow chamber being attached to one or more second resilient means extending from the mounting point in static equilibrium such that the center of mass of the hollow member is aligned with the second resilient means at a vertical axis; a plurality of piezoelectric material-built cantilevers mounted on the hollow member; an integrated circuit connecting the hollow chamber, hollow member, and piezoelectric material-built cantilevers with at least one of a primary storage and a device, wherein the energy is harvested through vibration of the plurality of piezoelectric material-built cantilevers at its approximately resonant frequency, reciprocation of the hollow chamber and the hollow member upon application of a force.