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.

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.

In a particular embodiment, a pressure sensor apparatus for strain gauge pressure sensing is disclosed that includes a plurality of strain gauges comprising a first strain gauge and a second strain gauge. The pressure sensor apparatus also includes a diaphragm coupled between the plurality of strain gauges and an object configured to apply pressure to the diaphragm. The diaphragm has a first portion and a second portion. The first portion has a first thickness between the object and the first strain gauge. The second portion has a second thickness between the object and the second strain gauge. In an uncompressed state, the second thickness is greater than the first thickness.

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.

According to one embodiment, a pressure sensor includes a base body, a supporter, a film part, a first electrode, and a second electrode. The supporter is fixed to the base body. The film part is separated from the base body. The film part includes first, second, and third partial regions, and a rim portion. The rim portion is supported by the supporter. The second partial region is between the first partial region and the rim portion. The third partial region is between the second partial region and the rim portion. The first electrode is provided between the base body and the first partial region and between the base body and the second partial region. The first electrode is fixed to the base body. The second electrode is provided between the first electrode and the first partial region and between the first electrode and the second partial region.

A pressure sensor includes: a substrate having first and second main surfaces and having a thickness in first direction; a first chamber recessed from the first main surface in the first direction with respect to the substrate; a second chamber recessed from the first main surface in the first direction with respect to the substrate and adjacent to the first chamber in second direction; a fluid passage recessed from the first main surface in the first direction with respect to the substrate and causing the first chamber to be in fluid communication with an outside; a closing layer laminated on the first main surface of the substrate and closing openings of the first chamber and the second chamber; and a membrane partitioned by the first and second chambers in the second direction and extending in a plane parallel to the first direction and a third direction.

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 capacitive pressure sensor (10) is disclosed comprising a membrane (21) including a second electrode (23) spatially separated by a cavity (20) from a substrate (11) including a first electrode (13) opposing the second electrode; and a central pillar (22) extending from the membrane to the substrate such that the cavity is an annular cavity enveloping said central pillar. Also disclosed is an invasive medical instrument comprising such a capacitive pressure sensor and a method of manufacturing such a capacitive pressure sensor.

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 MEMS pressure sensor includes a first plate with a hole on a diaphragm bonded to the first plate around its rim with the diaphragm positioned over the hole. An isolation frame is bonded to the diaphragm and a second plate with a pillar is bonded to the isolation frame around its rim to form a cavity such that the end of the pillar in the cavity is proximate a surface of the diaphragm. The diaphragm and second plate form a capacitive sensor which changes output upon deflection of the diaphragm relative to the second plate.