Energy harvesting from radio frequency propagation using piezoelectric cantilevers

This work reports an induced strain in a piezoelectric cantilever due to radio frequency signal propagation. The piezoelectric actuator is coupled to radio frequency (RF) line through a gap of 0.25 mm. When a voltage signal of 10 Vpp propagates in the line it sets an alternating current in the actuator electrodes. This flowing current drives the piezoelectric cantilever to mechanical movement, especially when the frequency of the RF signal matches the mechanical resonant frequency of the cantilever. Output voltage signals versus frequency for both mechanical vibrational and RF signal excitations have been measured using different loads.

► Induced motion of a piezoelectric cantilever by coupling to radio frequency signal propagation is demonstrated.
► An expression for output power as a function of RF signal power, device capacitance, impedance, and load was derived.
► Output voltage signals versus frequency and load for mechanical vibrational and RF signal excitations have been measured.
► Power output is maximum when RF input signal frequency matches the resonance frequency of the cantilever structure.