A microelectromechanical system (MEMS) device includes a first movable element and a second movable element, wherein the second movable element is connected with a movable membrane for sensing pressure to make the second movable element move with the movable membrane to sense the pressure variation of the external environment, and other portion of the substrate forming the movable membrane can form a cap to protect the first movable element for sensing other physical quantity.

Accordingly, the pressure sensor and the MEMS structure for sensing other physical quantity can be integrated in the foregoing MEMS device by a single process.

A pressure capsule/header assembly for a process fluid pressure transmitter is provided. An isolator plug has an isolation diaphragm at a first end thereof and a second end spaced from the first end. The isolator plug has a fill fluid passageway fluidically coupling the first end to the second end. A header has a first end configured to carry a pressure sensor and a second end spaced from the first end. The header has at least one electrical interconnect extending from the first end to the second end. A biaxial support ring is disposed about an outer surface of the header. The biaxial support ring and the header define a tapered interference interface therebetween. The header is welded to the isolator plug at a first weld and the biaxial support ring is welded to the isolator plug at a location that is spaced from the second end of the header.

A method of manufacturing an overheat or fire alarm detection system, comprises the steps of micromachining a pressure sensor and securing a sensor tube in fluid communication with the pressure sensor. The sensor tube may comprise a hollow tube containing a material that evolves gas upon heating. The micromachining step may comprise doping at least a portion of a first layer, forming a cavity at least partially within the doped portion and forming a deformable diaphragm over the cavity.

A method of manufacturing an overheat or fire alarm detection system, comprises the steps of micromachining a pressure sensor and securing a sensor tube in fluid communication with the pressure sensor. The sensor tube may comprise a hollow tube containing a material that evolves gas upon heating. The micromachining step may comprise doping at least a portion of a first layer, forming a cavity at least partially within the doped portion and forming a deformable diaphragm over the cavity.

An apparatus for measuring pressure within a fluid path includes a housing defining the structure of the apparatus. The housing includes a fluid path that extends through the housing and allows a fluid to pass through the housing. The apparatus also includes a first volume chamber that is in fluid communication with the fluid path and has a first volume chamber opening, and a second volume chamber with a second volume chamber opening that is less than the first volume chamber opening. A diaphragm separates the first volume chamber from the second volume chamber and fluidly disconnects the second volume chamber from the fluid path. The diaphragm deforms based upon the pressure within the fluid path. The apparatus also includes an interface that is connectable to a pressure sensor, and the second volume chamber is in fluid communication with the interface.

A pressure sensor includes a substrate that has a diaphragm which bends and deforms by receiving pressure and a displacement regulating unit that regulates deformation of the diaphragm, in which the diaphragm and the displacement regulating unit are spaced away from each other in a first state where the diaphragm receives pressure within a measurable range, and the diaphragm and the displacement regulating unit come into contact with each other in a second state where the diaphragm receives pressure exceeding the measurable range.

Embodiments provide a fluid detection device including a casing connectable to a tube filled with water and allows the water to flow to a hollow inner part; a partition wall deformable so that the hollow inner part is divided into a fluid chamber filled with the water and an air chamber opened to the atmosphere; a slide tip disposed inside the fluid chamber; and a tip sensor disposed outside the casing. According to at least one embodiment, a slide holding part which holds the slide tip slidably forward and backward is formed inside the fluid chamber, an opening part is formed in the air chamber, a magnet is disposed in the casing, the slide tip includes a magnet provided at a position facing the magnet and repelling the magnet.

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 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 waterproof member includes a laminated body including a second silicon layer and a second silicon oxide layer, and a through hole that is provided in the laminated body, prevents passing of liquid, and allows passing of gas, the through hole includes a first through hole that passes through the second silicon layer, and a second through hole passing through the second silicon oxide layer and communicating with the first through hole, and a width of the second through hole is smaller than a width of the first through hole.