High Q-factor Electro-Acoustic Cavity Resonator for Sensing Applications

Sound waves are sensitive to environmental perturbation effects and therefore offer great potential for non-invasive sensing of background temperature, pressure or bio-chemical materials. This paper presents a robust design of electromechanical cavity that can supports high Q resonance for the incident sound waves. The electromechanical cavity consists of subwavelength sized tube residing on a piezoelectric substrate. The cavity utilizes piezoelectric base to absorb and convert incident sound waves to resonant electric currents. At the same time the residue resonant acoustic energy is also back reflected in the form of scattered acoustic fields. The resonator is specially designed to enhance the sound matter interactions towards the base of the cavity and therefore increase the sound energy harvesting many folds. The proposed design of electromechanical resonator cavity system offers potential for low cost and ultrasensitive environmental sensing applications.