In a method of inferring ambient atmospheric temperature, an acoustic signal is emitted from a speaker. A first sample of the acoustic signal is captured with a first microphone spaced a first distance from the speaker. A second sample of the acoustic signal is captured with a second microphone spaced a second distance from the speaker. The second distance is greater than the first distance, and a difference between the first distance and the second distance is a known third distance. A time delay in the acoustic signal is determined between the first sample and the second sample. An ambient temperature of the atmosphere through which the acoustic signal traveled is inferred based on a relationship between the time delay and temperature for the acoustic signal over the third distance.

Various embodiments of the present disclosure are directed towards a method for forming an integrated chip including an epitaxial layer overlying a microelectromechanical systems (MEMS) substrate. The method includes bonding a MEMS substrate to a carrier substrate, the MEMS substrate includes monocrystalline silicon. An epitaxial layer is formed over the MEMS substrate, the epitaxial layer has a higher doping concentration than the MEMS substrate. A plurality of contacts are formed over the epitaxial layer, the plurality of contacts respectively form ohmic contacts with the epitaxial layer.

Method of manufacturing a microfluidic device comprising an inflexible polymeric substrate, one or more flexible polymeric substrate(s) and one or more microfluidic channel(s) enclosed between the substrates comprising a) providing a master form including rim protrusions defining an enveloping shape for the microfluidic channel(s) to be produced and enclosed between the substrates, b) placing one or more flexible polymeric substrate(s) each having a layer thickness of less than 800 m onto the master form, wherein one flexible polymeric substrate is in contact with the rim protrusions of the master form, c) placing an inflexible polymeric substrate with a layer thickness of equal to or more than 800 m onto the flexible polymeric substrate(s), and d) ultrasonically welding the one or more flexible polymeric substrate(s) and the inflexible polymeric substrate at the rim protrusions. By the inventive method microfluidic devices via ultrasonic welding without using energy directors can be obtained.

Disclosed is a flexible electronic circuit substrate that includes a device that is fabricated from layers of the flexible electronic circuit substrate as part of construction of the flexible electronic circuit substrate. Such devices could be functional units such as micro electro mechanical devices (MEMS) devices such as micro-accelerometer sensor elements, micro flow sensors, micro pressure sensors, etc.

A method of processing a double sided wafer of a microelectromechanical device includes spinning a resist onto a first side of a first wafer. The method further includes forming pathways within the resist to expose portions of the first side of the first wafer. The method also includes etching one or more depressions in the first side of the first wafer through the pathways, where each of the depressions have a planar surface and edges. Furthermore, the method includes depositing one or more adhesion metals over the resist such that the one or more adhesion metals are deposited within the depressions, and then removing the resist from the first wafer. The method finally includes depositing indium onto the adhesion metals deposited within the depressions and bonding a second wafer to the first wafer by compressing the indium between the second wafer and the first wafer.

A microelectromechanical device having a first substrate of semiconductor material and a second substrate of semiconductor material having a bonding recess delimited by projecting portions, monolithic therewith. The bonding recess forms a closed cavity with the first substrate. A bonding structure is arranged within the closed cavity and is bonded to the first and second substrates. A microelectromechanical structure is formed in a substrate chosen between the first and second substrates. The device is manufactured by forming the bonding recess in a first wafer; depositing a bonding mass in the bonding recess, the bonding mass having a greater depth than the bonding recess; and bonding the two wafers.

The performance of a microelectromechanical systems (MEMS) device may be subject to unwanted thermal gradients or nonuniform temperatures. The thermal gradients may be approximated based on voltage measurements taken through bond wires coupled to bond points located on the MEMS device. Thermal gradient measurement may be improved depending on the arrangement of bond wires and/or the material of the bond wires. Sense circuitry that is coupled to the MEMS device may determine corrective actions, such as updating the operation of the MEMS device, that compensate for the adverse effects from the thermal gradients.

A device with a membrane comprising a support, a membrane made of a polymer material suspended on said support and at least one actuating module arranged opposite a face of the membrane and separate from said membrane, said actuating module comprising at least one actuator comprising at least one piezoelectric material and a beam connected to the support and separate from the membrane, the piezoelectric material being connected to the beam, such that, when a difference in electric potential is applied to the piezoelectric material, a bimetal effect appears between the piezoelectric material and the beam deforming the beam in the direction of the membrane, causing the deformation of the membrane, said device also comprising at least one electrostatic actuator configured for compressing at least one part of the membrane on the at least one part of the actuating module.

A method embodiment includes providing a MEMS wafer. A portion of the MEMS wafer is patterned to provide a first membrane for a microphone device and a second membrane for a pressure sensor device. A carrier wafer is bonded to the MEMS wafer. The carrier wafer is etched to expose the first membrane and a first surface of the second membrane to an ambient environment. A MEMS structure is formed in the MEMS wafer. A cap wafer is bonded to a side of the MEMS wafer opposing the carrier wafer to form a first sealed cavity including the MEMS structure and a second sealed cavity including a second surface of the second membrane for the pressure sensor device. The cap wafer comprises an interconnect structure. A through-via electrically connected to the interconnect structure is formed in the cap wafer.

A process for fabricating a symmetrical MEMS accelerometer. A pair of half parts is fabricated by, for each half part: (i) forming a plurality of resilient beams, first connecting parts, second connecting parts, and a plurality of comb structures, by etching a plurality of holes on a bottom surface of a first silicon wafer; (ii) etching a plurality of hollowed parts on a top surface of a second silicon wafer; (iii) forming a silicon dioxide layer on the top and bottom surface of the second silicon wafer; (iv) bonding the bottom surface of the first silicon wafer with the top surface of the second silicon wafer; (v) depositing a layer of silicon nitride on the bottom surface of the second silicon wafer, and removing parts of the silicon nitride layer and silicon dioxide layer on the bottom surface of the second silicon wafer; (vii) deep etching the exposed parts of the bottom surface of the second silicon wafer to the silicon dioxide layer located on the top surface of the second silicon wafer, and reducing the thickness of the first silicon wafer; and (viii) removing the silicon nitride layer, and etching the silicon dioxide to form the mass. The two half parts are then bonded along their bottom surface. The device is deep etched to form a movable accelerometer. A bottom cap is fabricated by hollowing out the corresponding area, and depositing metal as electrodes. The accelerometer is bonded with the bottom cap. Metal is deposited on the first silicon wafer to form electrodes.