Micromachined ultrasonic transducers having a self-assembled monolayer formed on a surface of a sealed cavity are described. A micromachined ultrasonic transducer may include a flexible membrane configured to vibrate over a sealed cavity, and the self-assembled monolayer may coat some or all of the interior surfaces of the sealed cavity. During fabrication, the sealed cavity may be formed by bonding the membrane to a substrate such that the sealed cavity is between the membrane and the substrate. An access hole may be formed through the membrane to the sealed cavity and the self-assembled monolayer is formed on surface(s) of the sealed cavity by introducing precursors into the sealed cavity through the access hole.

A method for manufacturing a MEMS unit for a micromechanical pressure sensor. The method includes the steps: providing a MEMS wafer including a silicon substrate and a first cavity formed therein, under a sensor membrane; applying a layered protective element on the MEMS water; and exposing a sensor core from the back side, a second cavity being formed between the sensor core and the surface of the silicon substrate, and the second cavity being formed with the aid of an etching process which is carried out with the aid of etching parameters changed in a defined manner; and removing the layered protective element.

The present invention provides a piezoelectric MEMS microphone having a base with a cavity, a piezoelectric diaphragm, and a restraining element. The base has a ring base circumferentially forming a cavity, a support column. The piezoelectric diaphragm includes diaphragm sheets each having a fixing end connected to a support column and a free end suspended over the cavity. The restraining element has one end fixedly connected to the free end, the other end connected to the part on the base that is not connected to the fixing end. The piezoelectric MEMS microphone of the invention can constrain the deformation of the diaphragm sheet, thereby improving the resonant frequency of the piezoelectric diaphragm, reducing the noise of the whole piezoelectric MEMS microphone.

A micro electro mechanical system (MEMS) microphone includes a first membrane, a second membrane, a third membrane disposed between the first membrane and the second membrane, a first cavity disposed between the first membrane and the third membrane and surrounded by a first wall, a second cavity disposed between the second membrane and the third membrane and surrounded by a second wall, and one or more first supports disposed in the first cavity and connecting the first membrane and the third membrane.

A method for manufacturing a device comprising a membrane extending over a useful cavity, the method comprising: providing a generic structure comprising a surface layer extending in a main plane and arranged on a first face of a support substrate, the support substrate comprising elementary cavities opening under the surface layer and partitions delimiting each elementary cavity, the partitions having top surfaces that form all or part of the first face of the support substrate; defining a group of adjacent elementary cavities, such that a contour of the group of elementary cavities corresponds, in the main plane, to a contour of the useful cavity; and removing the partitions situated within the contour of the group of elementary cavities, in order to form the useful cavity, and to free the surface layer arranged above the useful cavity and forming the membrane.

Substrates comprising a functionalizable layer, a polymer layer comprising a plurality of micro-scale or nano-scale patterns, or combinations thereof, and a backing layer and the preparation thereof by using room-temperature UV nano-embossing processes are disclosed. The substrates can be prepared by a roll-to-roll continuous process. The substrates can be used as flow cells, nanofluidic or microfluidic devices for biological molecules analysis.

MEMS devices comprise a filter configured and arranged to inhibit the entry of particles into at least a region of the interior of the substrate cavity from a region underlying the substrate.

A device having both an electronic assembly having an electronic component assembled on a first substrate, and also a body defining a cavity having a first end in fluid flow communication with a fluid, the electronic component extending inside the cavity and the first substrate including a portion in contact with a wall of the cavity. The coefficient of thermal expansion of the material of the first substrate is less than that of the electronic component, and the electronic component is assembled on the first substrate by a brazing type assembly method involving the application of heat. A method of making an electronic assembly. An assembly obtained by the method.

A microphone assembly includes: a microphone with a first acoustic port, wherein the microphone is configured to convert acoustic waves into an electric signal; a filter housing with a second acoustic port; and a carrier coupled to the microphone and to the filter housing, wherein the carrier and the filter housing together enclose a cavity with a first acoustic passage fluidly connecting the first acoustic port and the second acoustic port; wherein the cavity comprises an acoustic chamber and a second acoustic passage; and wherein the second acoustic passage is in fluid communication with the first acoustic passage and with the acoustic chamber, and wherein the acoustic chamber and the second acoustic passage together establish a Helmholtz resonator for suppressing acoustic energy within a first frequency band in the acoustic waves propagating through the first acoustic passage, wherein the first frequency band is in an ultrasound frequency domain.

A MEMS device can include a first support layer, a second support layer, and a solid dielectric suspended between the first support layer and the second support layer. The solid dielectric can move relative to the first support layer and the second support layer and can include a plurality of apertures. The MEMS device can include a first plurality of electrodes coupled to the first support layer and the second support layer and extending through a first subset of the plurality of apertures. The MEMS device can include a second plurality of electrodes coupled to the first support layer and extending partially into a second subset of the plurality of apertures. The MEMS device can include a third plurality of electrodes coupled to the second support layer and extending partially into a third subset of the plurality of apertures.