A parametric resonator can be driven by varying a parameter of a modulated capacitor or other externally powered type device to achieve transduction. Conventionally, externally powered type devices generally require an external power source or a static charge to achieve transduction. By pumping the parameter of the device at a frequency that is about twice the resonance frequency, and an amplitude that is above a threshold, however parametric resonance can be generated and sustained without requiring an external power source or charge to be applied to the device.