US Patent 11064285 Tunable contact microphone

A tunable contact microphone is fabricated from nanometer size piezoelectric materials. The piezoelectric nanostructures are deposited on a flexible substrate or tunable resonant backplane. The backplane can be designed to vibrate at fundamental harmonic or sub-harmonic frequencies from 10 Hz to 20 KHz, corresponding to vibration frequencies of the human cranium. The backplane can be attached to a band or other material that will facilitate the attachment to the forehead, behind the ear or throat, with a preferred location being the forehead. When a person speaks, the backplane vibrates causing the nanostructures to generate electricity. The electrical signals are sent to an impedance matching preamplifier. The signal can then be sent to a communications system or fed into the microphone input of a communication system.