US Patent 7493821 Micromachined acoustic transducer and method of operating the same

This invention relates generally to a micromachined acoustic transducer that has a scalable array of sealed cavities and perforated members forming capacitive cells that convert the electrical signal to acoustic signal or vice versa. It also relates to the method and more particularly to a micromachined acoustic transducer which includes a plurality of micromachined membranes and perforated members forming capacitive cells and more particularly to an acoustic transducer in which the capacitive cells are connected in a scalable array whereby electrical signals are applied to the said array and converted to acoustic signals. The transducer can either be used as an acoustic actuator or a microphone.