We describe a mechanical vibration-based energy harvester deploying a flexible body beam to lower the spring constant of the device so that high-mode resonant frequencies are shifted down into a useable frequency range under natural environmental conditions. Whereas conventional cantilevers feature a single resonant frequency within this range, the proposed device generates multiple high-mode resonant frequencies in close proximity to form a wider operational bandwidth that is over 400% wider than that of conventional cantilever-type energy harvesters. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754147]