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.