Abstract: A microphone assembly can include a microelectromechanical systems (MEMS) transducer comprising a transducer substrate, a diaphragm oriented substantially parallel to the transducer substrate and spaced apart from the transducer substrate to form a gap, and a counter electrode coupled to the transducer substrate, the counter electrode positioned between the diaphragm and the transducer substrate. The MEMS transducer can generate a signal representative of a change in capacitance between the counter electrode and the diaphragm. A back volume of the MEMS transducer can be an enclosed volume positioned between the transducer substrate and the diaphragm. The microphone assembly can include an integrated circuit that receives the signal, wherein every point within the back volume is less than a thermal boundary layer thickness from a nearest solid surface at an upper limit of an audio frequency band that the integrated circuit is monitoring.

Abstract: A method of forming an acoustic transducer comprises providing a substrate and depositing a first structural layer on the substrate. The first structural layer is selectively etched to form at least one of an enclosed trench or an enclosed pillar thereon. A second structural layer is deposited on the first structural layer and includes a depression or a bump corresponding to the enclosed trench or pillar, respectively. At least the second structural layer is heated to a temperature above a glass transition temperature of the second structural layer causing the second structural layer to reflow. A diaphragm layer is deposited on the second structural layer such that the diaphragm layer includes at least one of a downward facing corrugation corresponding to the depression or an upward facing corrugation corresponding to the bump. The diaphragm layer is released, thereby forming a diaphragm suspended over the substrate.

Abstract: A MEMS diaphragm assembly comprises a first diaphragm, a second diaphragm, and a stationary electrode assembly spaced between the first and second diaphragms and including a plurality of apertures disposed therethrough. Each of a plurality of pillars is disposed through one of the plurality of apertures and connects the first and second diaphragms. At least one of the first and second diaphragms is connected to the stationary electrode assembly at a geometric center of the assembly.

Abstract: A microelectromechanical systems (MEMS) die includes a first diaphragm and a second diaphragm, wherein the first diaphragm and the second diaphragm bound a sealed chamber. A stationary electrode is disposed within the sealed chamber between the first diaphragm and the second diaphragm. A tunnel passes through the first diaphragm and the second diaphragm without passing through the stationary electrode, wherein the tunnel is sealed off from the chamber. The MEMS die further includes a substrate having an opening formed therethrough, wherein the tunnel provides fluid communication from the opening, through the second diaphragm, and through the first diaphragm.

Abstract: In accordance with one aspect, a device is provided having a transducer comprising a conductor, a diaphragm configured to move relative to the conductor, and a reference volume in communication with the external environment. The diaphragm separates the reference volume and the external environment. The device further includes a controller operably coupled to the transducer and configured to determine an air pressure of an external environment based at least in part on movement of the diaphragm.

Abstract: A MEMS die includes a substrate having an opening formed therein, a diaphragm having a first surface attached around a periphery thereof to the substrate and over the opening, and a backplate separated from a second surface of the diaphragm. The diaphragm includes at least one passage disposed between the first and second surfaces, and the at least one passage has a smaller cross-sectional area at the first surface than at the second surface.

Abstract: A microphone device includes a base and a microelectromechanical system (MEMS) transducer and an integrated circuit (IC) disposed on the base. The microphone device also includes a cover mounted on the base and covering the MEMS transducer and the IC. The MEMS transducer includes a diaphragm attached to a surface of the substrate and a back plate mounted on the substrate and in a spaced apart relationship with the diaphragm. The diaphragm is attached to the surface of the substrate along at least a portion of a periphery of the diaphragm. The diaphragm can include a silicon nitride insulating layer, and a conductive layer, that faces a conductive layer of the back plate. The MEMS transducer can include a peripheral support structure that is disposed between at least a portion of the diaphragm and the substrate. The diaphragm can include one or more pressure equalizing apertures.

Abstract: A microelectromechanical systems (MEMS) diaphragm assembly comprises a first diaphragm and a second diaphragm. A plurality of pillars connects the first and second diaphragms, wherein the plurality of pillars has a higher distribution density at a geometric center of the MEMS diaphragm assembly than at an outer periphery thereof.

Abstract: A MEMS diaphragm assembly comprises a first diaphragm, a second diaphragm, and a stationary electrode assembly spaced between the first and second diaphragms and including a plurality of apertures disposed therethrough. Each of a plurality of pillars is disposed through one of the plurality of apertures and connects the first and second diaphragms. At least one of the first and second diaphragms is connected to the stationary electrode assembly at a geometric center of the assembly.

Abstract: An acoustic transducer for generating electrical signals in response to acoustic signals, comprises a first diaphragm having a first corrugation formed therein. A second diaphragm has a second corrugation formed therein, and is spaced apart from the first diaphragm such that a cavity having a pressure lower than atmospheric pressure is formed therebetween. A back plate is disposed between the first diaphragm and the second diaphragm. One or more posts extend from at least one of the first diaphragm or the second diaphragm towards the other through the back plate. The one or more posts prevent each of the first diaphragm and the second diaphragm from contacting the back plate due to movement of the first diaphragm and/or the second diaphragm towards the back plate. Each of the first corrugation and the second corrugation protrude outwardly from the first diaphragm and the second diaphragm, respectively, away from the back plate.

Abstract: A microelectromechanical systems (MEMS) die includes a first diaphragm and a second diaphragm, wherein the first diaphragm and the second diaphragm bound a sealed chamber. A stationary electrode is disposed within the sealed chamber between the first diaphragm and the second diaphragm. A tunnel passes through the first diaphragm and the second diaphragm without passing through the stationary electrode, wherein the tunnel is sealed off from the chamber. The MEMS die further includes a substrate having an opening formed therethrough, wherein the tunnel provides fluid communication from the opening, through the second diaphragm, and through the first diaphragm.

Abstract: A microphone assembly can include a microelectromechanical systems (MEMS) transducer comprising a transducer substrate, a diaphragm oriented substantially parallel to the transducer substrate and spaced apart from the transducer substrate to form a gap, and a counter electrode coupled to the transducer substrate, the counter electrode positioned between the diaphragm and the transducer substrate. The MEMS transducer can generate a signal representative of a change in capacitance between the counter electrode and the diaphragm. A back volume of the MEMS transducer can be an enclosed volume positioned between the transducer substrate and the diaphragm. The microphone assembly can include an integrated circuit that receives the signal, wherein every point within the back volume is less than a thermal boundary layer thickness from a nearest solid surface at an upper limit of an audio frequency band that the integrated circuit is monitoring.

Abstract: A microelectromechanical systems (MEMS) diaphragm assembly comprises a first diaphragm and a second diaphragm. A plurality of pillars connects the first and second diaphragms, wherein the plurality of pillars has a higher distribution density at a geometric center of the MEMS diaphragm assembly than at an outer periphery thereof.

Abstract: A microelectromechanical systems (MEMS) device comprises a diaphragm assembly and a force feedback system. The diaphragm assembly includes a first diaphragm and a second diaphragm facing the first diaphragm, with a low pressure region being defined therebetween. The diaphragm assembly further includes a first plurality of electrodes, a second plurality of electrodes, and a third plurality of electrodes. A solid dielectric is spaced between the first and second diaphragms and includes a plurality of apertures. Each electrode of the first, second, and third pluralities of electrodes is disposed at least partially within an aperture of the plurality of apertures. The force feedback system receives output from the diaphragm assembly and produces a feedback voltage that is applied to the diaphragm assembly to produce an electrostatic force on the diaphragm assembly that counters a low-frequency pressure across the diaphragm assembly.

Abstract: A MEMS transducer includes a transducer substrate, a counter electrode, and a diaphragm. The counter electrode is coupled to the transducer substrate. The diaphragm is oriented substantially parallel to the counter electrode and is spaced apart from the counter electrode to form a gap. A back volume of the MEMS transducer is an enclosed volume positioned between the counter electrode and the diaphragm. A height of the gap between the counter electrode and the diaphragm is less than two times the thermal boundary layer thickness within the back volume at an upper limit of the audio frequency band of the MEMS transducer.

Abstract: A microelectromechanical systems (MEMS) device comprises a diaphragm assembly and a force feedback system. The diaphragm assembly includes a first diaphragm and a second diaphragm facing the first diaphragm, with a low pressure region being defined therebetween. The diaphragm assembly further includes a first plurality of electrodes, a second plurality of electrodes, and a third plurality of electrodes. A solid dielectric is spaced between the first and second diaphragms and includes a plurality of apertures. Each electrode of the first, second, and third pluralities of electrodes is disposed at least partially within an aperture of the plurality of apertures. The force feedback system receives output from the diaphragm assembly and produces a feedback voltage that is applied to the diaphragm assembly to produce an electrostatic force on the diaphragm assembly that counters a low-frequency pressure across the diaphragm assembly.

Abstract: An acoustic transducer comprises a transducer substrate having an aperture defined therethrough. At least one diaphragm is disposed on the transducer substrate over the aperture. A back plate is disposed on the transducer substrate and axially spaced apart from the at least one diaphragm. A perimetral support structure is disposed circumferentially between the at least one diaphragm and the back plate at a radially outer perimeter of the back plate. A plurality of perimetral release holes are defined circumferentially through at least one of the at least one diaphragm or the back plate proximate to and radially inwards of the perimetral support structure, at least a portion of the plurality of perimetral release holes defining a non-circular shape.

Abstract: A micro-electro-mechanical systems (MEMS) die includes a piston; an electrode facing the piston, wherein a capacitance between the piston and the electrode changes as the distance between the piston and the electrode changes; and a resilient structure (e.g., a gasket or a pleated wall) disposed between the piston and the electrode, wherein the resilient structure supports the piston and resists the movement of the piston with respect to the electrode. A back volume is bounded by the piston and the resilient structure and the resilient structure blocks air from leaving the back volume. The piston may be a rigid body made of a conductive material, such as metal or a doped semiconductor. The MEMS die may also include a second resilient structure, which provides further support to the piston and is disposed within the back volume.

Abstract: A MEMS die includes a substrate having an opening formed therein, a diaphragm having a first surface attached around a periphery thereof to the substrate and over the opening, and a backplate separated from a second surface of the diaphragm. The diaphragm includes at least one passage disposed between the first and second surfaces, and the at least one passage has a smaller cross-sectional area at the first surface than at the second surface.

Abstract: A microphone device includes a base and a microelectromechanical system (MEMS) transducer and an integrated circuit (IC) disposed on the base. The microphone device also includes a cover mounted on the base and covering the MEMS transducer and the IC. The MEMS transducer includes a diaphragm attached to a surface of the substrate and a back plate mounted on the substrate and in a spaced apart relationship with the diaphragm. The diaphragm is attached to the surface of the substrate along at least a portion of a periphery of the diaphragm. The diaphragm can include a silicon nitride insulating layer, and a conductive layer, that faces a conductive layer of the back plate. The MEMS transducer can include a peripheral support structure that is disposed between at least a portion of the diaphragm and the substrate. The diaphragm can include one or more pressure equalizing apertures.