A sensor membrane structure is provided. The sensor membrane structure includes a substrate, a first insulating layer, and a device layer. The substrate has a first surface and a second surface that is opposite to the first surface. A cavity is formed on the first surface, an opening is formed on the second surface, and the cavity communicates with the opening. The cavity and the opening penetrate the substrate in a direction that is perpendicular to the first surface. The first insulating layer is disposed on the first surface of the substrate. The device layer is disposed on the first insulating layer. The first insulating layer is disposed for protecting the sensor membrane structure from overetched and remain stable during the etching process, increasing the yield of the sensor membrane structure.

A differential MEMS pressure sensor includes a topping wafer with a top side and a bottom side, a diaphragm wafer having a top side connected to the bottom side of the topping wafer and a bottom side, and a backing wafer having a top side connected to the bottom side of the diaphragm wafer and a bottom side. The topping wafer includes a first cavity formed in the bottom side of the topping wafer. The diaphragm wafer includes a diaphragm, a second cavity formed in the bottom side of the diaphragm wafer underneath the diaphragm, an outer portion surrounding the diaphragm, and a trench formed in the top side of the diaphragm wafer and positioned in the outer portion surrounding the diaphragm.

Disclosed is a pressure sensing element that is formed using a semiconductor substrate, the pressure sensing element including: a frame; a diaphragm that is supported by the frame; and a piezoresistor that is arranged on the diaphragm. The diaphragm includes a trench and a plurality of beams, the beams are arranged such that the beams connect a portion around an edge of the diaphragm to a portion around a center of the diaphragm and the beams cross each other in the portion around the center of the diaphragm, and a beam that is each of the beams includes a narrow portion that has a first width and a wide portion that has a second width wider than the first width.

We present a microelectromechanical system (MEMS) graphene-based pressure sensor realized by transferring a large area, few-layered graphene on a suspended silicon nitride thin membrane perforated by a periodic array of micro-through-holes. Each through-hole is covered by a circular drum-like graphene layer, namely a graphene “microdrum”. The uniqueness of the sensor design is the fact that introducing the through-hole arrays into the supporting nitride membrane allows generating an increased strain in the graphene membrane over the through-hole array by local deformations of the holes under an applied differential pressure. Further reasons contributing to the increased strain in the devised sensitive membrane include larger deflection of the membrane than that of its imperforated counterpart membrane, and direct bulging of the graphene microdrum under an applied pressure. Electromechanical measurements show a gauge factor of 4.4 for the graphene membrane and a sensitivity of 2.8×10-5 mbar-1 for the pressure sensor specific example described, with a good linearity over a wide pressure range. The present sensor outperforms most existing MEMS-based small footprint pressure sensors using graphene, silicon, and carbon nanotubes as sensitive materials, due to the high sensitivity.

A diaphragm pressure transducer includes a body having an outer surface and a diaphragm, a strain gauge including a resistive element located on the outer surface, a fluidic inlet, and a fluidic cavity enclosed by the body in fluidic communication with the fluidic inlet, the fluidic cavity having an upper surface. The diaphragm is located between the upper surface of the fluidic cavity and the outer surface of the body. The diaphragm includes a variable thickness across a region defined between the upper surface of the fluidic cavity and the outer surface located below the strain gauge.

A pressure sensor includes a diaphragm of a thin plate shape, the diaphragm forming part of a wall surface of a pressure chamber into and out from which a measurement target fluid flows. Multiple recesses are formed in the diaphragm on a side in contact with the measurement target fluid, and an interval between adjacent two of the multiple recesses is 10 μm or less.

A pressure detector includes a first board with a first pressure inlet, a first groove, and a first board electrode; a second board with a second pressure inlet, a second groove, and a second board electrode; and a sensing unit arranged therebetween with a diaphragm. The first groove is in communication with the first pressure inlet so as to prevent the formation of a closed space between the first board and the diaphragm when they contact with each other. The second groove is in communication with the second pressure inlet so as to prevent the formation of a closed space between the second board and the diaphragm when they contact each other.

PMUT acoustic transducer formed in a body of semiconductor material having a face and accommodating a plurality of first buried cavities, having an annular shape, arranged concentrically with each other and extending at a distance from the face of the body. The first buried cavities delimit from below a plurality of first membranes formed by the body so that each first membrane extends between a respective first buried cavity of the plurality of first buried cavities and the face of the body. A plurality of piezoelectric elements extend on the face of the body, each piezoelectric element extending above a respective first membrane of the plurality of first membranes. The first membranes have different widths, variable between a minimum value and a maximum value.

Semiconductor MEMS pressure sensors that can produce a linear and large output signal when subject to a small pressure, without an increase to the front to back span error. One example can experience large deflections without causing catastrophic damage to the membrane. The pressure sensor can include a silicon layer having opposing surfaces, an etched pattern in of the surfaces of the silicon layer, and an etched cavity on the opposite surface of the silicon layer to form a membrane. The etched patterned can include a series of concentric stiffening ribs, an inverted boss, large depression areas next to the membrane edge and/or the boss, and piezoresistive strain concentrators. The ribs and depressions can be formed onto the silicon membrane by anisotropic or isotropic etch techniques. Piezoresistive devices can be diffused into the membrane in the regions near the strain concentrators to form a Wheatstone bridge or other measurement structure.

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.