Abstract: An acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and a distal portion that extends from the proximal portion to a free end of the beam, the beam extending generally linearly from the proximal portion toward the free end in a first direction. The beam has a wall portion at or proximate the free end that extends in a second direction generally transverse to the first direction and increases an acoustic resistance of the gap between sensors. An electrode is disposed on or in the proximal portion of the beam.

Abstract: A method for manufacturing a microelectromechanical systems microphone comprises depositing a membrane on a first sacrificial layer on a substrate, releasing the membrane by removing the first sacrificial layer, depositing a resist layer on the membrane, and patterning the resist layer to expose the membrane, such that at least one section of resist layer remains at at least one edge of the membrane to form an anchor. A microphone manufactured by this method is also provided. There is also provided a method for manufacturing a microelectromechanical systems microphone comprising depositing a membrane on a first sacrificial layer deposited on a substrate, releasing the membrane by removing at least the first sacrificial layer, depositing a resist layer on membrane, patterning the resist layer to expose an edge of the membrane, and forming an anchor at the exposed edge of the membrane. A microphone manufactured by this method is also provided.

Abstract: A piezoelectric microelectromechanical system microphone comprises a support substrate, a diaphragm including a piezoelectric material attached to the support substrate and configured to deform and generate an electrical potential responsive to impingement of sound waves on the diaphragm, and a compliant anchor formed of a material with a greater compliance than a compliance of the piezoelectric material, the compliant anchor defined in the diaphragm in an anchor region between the piezoelectric material of the diaphragm and the support substrate to improve sensitivity and reduce residual stress impact of the piezoelectric microelectromechanical system microphone.

Abstract: A bulk acoustic resonator comprises a membrane including a piezoelectric film having multiple layers of piezoelectric material. At least one of the multiple layers of piezoelectric material has a different dopant concentration than another of the multiple layers of piezoelectric material.

Abstract: A piezoelectric microelectromechanical systems device can include a cavity bounded by walls and an asymmetrical bimorph structure at least partially spanning the cavity that includes at least a piezoelectric layer and two electrode layers. The electrode layers can have relative thicknesses configured to compensate for expected temperature stress in the bimorph structure. Thus, metals having different thicknesses can be positioned and configured to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate. A method for making the piezoelectric microelectromechanical systems device is also provided.

Abstract: A system for compensating for thermal stress in piezoelectric microelectromechanical systems devices can have a piezoelectric layer at least partially spanning a cavity such that it generates electrical signals when external forces cause the piezoelectric layer to vibrate with respect to the cavity. At least one electrode layer can include a conductive metal positioned adjacent the piezoelectric layer and configured as an electrode to accept the electrical signals. The piezoelectric layer and electrode layer can have an expected thermal stress tending to cause expected deflection even when external forces are not causing the piezoelectric layer to vibrate. A compensation layer can be positioned adjacent at least one of the piezoelectric layer and the at least one electrode layer and configured to counteract the expected deflection from the expected thermal stress.

Abstract: A piezoelectric microelectromechanical systems device is provided, having a first piezoelectric layer, a first metal layer including a first metal, a second metal layer including a second metal, the first and second metals having different properties to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate including at least one wall defining a cavity and the at least one wall supporting the layers. The method for making the piezoelectric microelectromechanical systems device is also provided.

Abstract: A piezoelectric microelectromechanical system microphone comprises a support substrate, a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric element, the piezoelectric element attached to the support substrate about a perimeter of the piezoelectric element, a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential, and corrugations defined in the piezoelectric element about the perimeter of the piezoelectric element to release residual stress and improve sensitivity of the piezoelectric microelectromechanical system microphone.