Abstract: The proposed vibrational energy harvester comprises a frame (118), a mass (114) coupled to first and second primary flexures (110, 112) which are configured to flex and allow the mass to move in a first direction (130), a plurality of secondary flexures (120, 122) which are configured to flex and allow the mass to move in a different second direction (132), and a transduction assembly configured to convert movement of the mass and flexures into electrical energy, preferably of electrodynamic or piezoelectric type. Each of the primary flexures is coupled to a secondary flexure at a position spaced from the mass. The resonant frequency of torsional vibration modes can thereby be raised to a frequency higher than the frequency band of ambient vibrations, which effectively prevents the energy harvester from vibrating in undesirable torsional modes that would result in wear between components.

Abstract: There is provided a vibrational energy harvester comprising: a frame, a flexure assembly coupled to the frame, the flexure assembly comprising a flexure configured to flex in a first direction relative to the frame and a mass fixed to the flexure, wherein when the mass is displaced in the first direction from a rest position, the flexure provides a restoring force on the mass to bring the mass back to the rest position, and a transduction assembly configured to convert movement of the mass and flexure into electrical energy, wherein the frame comprises a cavity positioned so that, if the mass is displaced in the first direction beyond a threshold distance, a portion of the flexure assembly extends into the cavity so that compression or restriction of fluid in the cavity applies an additional force on the flexure assembly.