Patent ID: 8531088

Claim:
A piezoelectric MEMS microphone, comprising: a substrate; and a multi-layer acoustic sensor comprising at least three layers including a first electrode layer, an intermediate layer of piezoelectric material deposited over said first electrode layer, and a second electrode layer deposited over said piezoelectric material; wherein said sensor is dimensioned such that an optimization parameter calculated according to the equation Optimization ⁢ ⁢ Parameter = V out 2 ⁢ C P 2 ⁢ A ⁢ ⁢ tan ⁡ ( δ ) · f res 2 is at least 10% of the maximum obtainable optimization parameter for the sensor, where V out is output voltage of the sensor, C is the capacitance of the sensor, P is the input pressure, A is the sensor area, tan(δ) is dielectric loss angle of the sensor at the sensor's first resonant frequency, and f res is the first resonant frequency; wherein said sensor comprises a plurality of beams each supported at one end by said substrate such that each beam is cantilevered and extends between a fixed end and a free end, each beam comprising said electrode and intermediate layers; and wherein at least two of said beams are positioned such that free ends of each beam face one another and are separated by a gap of no greater than 3 μm.