A pressure sensor includes a piezoelectric substrate having a generally planar structure and an anchor location fixing the piezoelectric substrate at the periphery of the planar structure of the piezoelectric substrate. The planar structure of the piezoelectric substrate has a first region having a first characteristic thickness adjacent to the anchor location, and a second region have a second characteristic thickness at a middle region of the substrate. The second characteristic thickness is less than the first characteristic thickness such that the planar structure in the second region is displaced relative to the neutral axis of the planar structure such that while undergoing bending the second region has either mostly compressive or mostly tensile stress.

A semiconductor pressure sensor includes a fixed electrode placed at a principal surface of a semiconductor substrate, and a diaphragm movable through an air gap in a thickness direction of the semiconductor substrate at least in an area where the diaphragm is opposed to the fixed electrode. The diaphragm includes: a movable electrode; a first insulation film placed closer to the air gap with respect to the movable electrode; a second insulation film placed opposite to the air gap with respect to the movable electrode, the second insulation film being of a same film type as the first insulation film; and a shield film that sandwiches the second insulation film with the movable electrode.

A pressure sensor die assembly for a differential pressure sensor comprises a base substrate including a first overpressure stop structure on a first surface, and a diaphragm structure coupled to the first surface. The diaphragm structure comprises a first side with a cavity section that includes a first cavity and a second cavity surrounding the first cavity, and a second side opposite from the first side. A pressure sensing diaphragm portion is defined by the first cavity and is located over the first overpressure stop structure. An overpressure diaphragm portion is defined by the second cavity. A top cap coupled to the second side of the diaphragm structure includes a second overpressure stop structure. The overpressure stop structures are each sized to support substantially all of a strained area of the pressure sensing diaphragm portion at an increasing overpressure on the first or second sides of the diaphragm structure.

A optical sensor assembly is disclosed that includes a sensor diaphragm configured to deflect responsive to an applied stimulus. The sensor assembly includes a first Extrinsic Fabry-Perot Interferometer (EFPI) having a first optical cavity in communication with at least a portion of the sensor diaphragm, the first EFPI is configured to interact with light to produce a combined measurement light signal and a first common-mode light signal, the measurement light signal corresponding to the applied stimulus. The sensor assembly also includes a second EFPI having a second optical cavity, the second EFPI is configured to interact with light to produce a second common mode light signal for error correction. The sensor assembly may further include a sensing optical fiber in communication with the first EFPI; a reference optical fiber in communication with the second EFPI; and a glass header configured to support the sensing optical fiber and the reference optical fiber.

The voltage output span and sensitivity from a MEMS pressure sensor are increased and pressure nonlinearity is reduced by thinning a diaphragm and forming the diaphragm to include anchors that are not connected to or joined to diaphragm-stiffening beams or thickened regions of the diaphragm.

Certain implementations of the disclosed technology may include systems and methods for extending a frequency response of a transducer. A method is provided that can include receiving a measurement signal from a transducer, wherein the measurement signal includes distortion due to a resonant frequency of the transducer. The method includes applying a complementary filter to the measurement signal to produce a compensated signal, wherein applying the complementary filter reduces the distortion to less than about +/−1 dB for frequencies ranging from about zero to about 60% or greater of the resonant frequency. The method further includes outputting the compensated signal.

Pressure sensors having ring-tensioned membranes are disclosed. A tensioning ring is bonded to a membrane in a manner that results in the tensioning ring applying a tensile force to the membrane, flattening the membrane and reducing or eliminating defects that may have occurred during production. The membrane is bonded to the sensor housing at a point outside the tensioning ring, preventing the process of bonding the membrane to the housing from introducing defects into the tensioned portion of the membrane. A dielectric may be introduced into the gap between the membrane and the counter electrode in a capacitive pressure sensor, resulting in an improved dynamic range.

A configuration for a capacitive pressure sensor uses a silicon on insulator wafer to create an electrically isolated sensing node across a gap from a pressure sensing wafer. The electrical isolation, small area of the gap, and silicon material throughout the capacitive pressure sensor allow for minimal parasitic capacitance and avoid problems associated with thermal mismatch.

A resonant pressure sensor includes a first substrate including a diaphragm and at least one projection disposed on the diaphragm, and at least one resonator disposed in the first substrate, at least a part of the resonator being included in the projection, and the resonator being disposed between a top of the projection and an intermediate level of the first substrate.

A MEMS capacitive pressure sensor is provided. The MEMS capacitive pressure sensor includes a substrate having a first region and a second region, and a first dielectric layer formed on the substrate. The capacitive pressure sensor also includes a second dielectric layer having a step surface profile formed on the first dielectric layer, and a first electrode layer having a step surface profile formed on the second dielectric layer. Further, the MEMS capacitive pressure sensor includes an insulation layer formed on the first electrode layer, and a second electrode layer having a step surface profile with a portion formed on the insulation layer in the peripheral region and the rest suspended over the first electrode layer in the device region. Further, the MEMS capacitive pressure sensor also includes a chamber having a step surface profile formed between the first electrode layer and the second electrode layer.