A vibrational energy harvesting apparatus comprising: a substrate having a plurality of integral compliant regions; at least two ferromagnetic masses each coupled to a corresponding one or more of the integral compliant regions such that at least one of the ferromagnetic masses moves with respect to the substrate responsive to substrate acceleration, each ferromagnetic mass having an inner magnetic pole disposed such that the inner magnetic poles are separated by a gap, wherein the magnetic polarities of the inner magnetic poles on the opposing sides of the gap are similar; wherein the inner magnetic poles form a steep flux gradient region in and around the gap; and a coil coupled to the substrate and disposed within the steep flux gradient region where it is exposed to a changing magnetic flux arising from motion of at least one of the ferromagnetic masses with respect to the substrate.