An energy harvesting device for generating electrical power from low-frequency oscillations includes a high-frequency cantilever, a plurality of low-frequency cantilevers each configured to contact the high-frequency cantilever in response to environmental vibrations having a frequency within a near-resonance frequency range associated with said low-frequency cantilever, an a generator that produces electrical power in response to contact between at least one of the plurality of low-frequency cantilevers and the high-frequency cantilever. The energy harvesting device may also include an impact mass coupled to a free end of each of the plurality of low-frequency cantilevers. Some aspects may include a common base to which the high-frequency cantilever and the plurality of low-frequency cantilevers are coupled. Other aspects may include the generator comprising one or more of an induction coil and magnet, a variable distance capacitor, or a piezo-electric material.