A micro check valve includes a substrate body having a top side and an underside, at least the top side having a sealing bar between a first trough and a second trough. The substrate body also has a passage which leads from the underside of the substrate body to the top side of the substrate body and ends on the top side of the substrate body in the first trough. In addition arranged on the top side of the substrate body is a diaphragm which is mounted flexibly at least in the region of the sealing bar and the first and second troughs. The diaphragm also has at least one through opening arranged above the second trough.

The present invention, in some embodiments thereof, provides a preparation method of a miniature solid silicon needle. The preparation method includes the following steps: growing one layer of silicon dioxide on a surface of monocrystalline silicon; depositing one layer of silicon nitride protective film on a surface of the silicon dioxide; coating a surface of the silicon nitride protective film with photoresist; and performing exposing, developing and etching, wherein the protective film adopts silicon nitride and is capable of accelerating etching reaction in the process of etching silicon, so that a diameter of a base of the silicon needle is smaller. According to the present invention, the process is simple, and the solid silicon needle has high durability and is suitable for transdermal drug permeation of biomacromolecule drugs.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.

A device includes a first layer of an electrically insulating material and a second layer of a non-electrically insulating material (e.g., semiconductor or electrically conductive) extending on the first layer. The second layer is structured so as to define opposite, lateral walls of a microchannel, a bottom wall of which is defined by an exposed surface of the first layer. The second layer is further structured to form one or more electrical insulation barriers; each barrier includes a line of through holes, each surrounded by an oxidized region of the material of the second layer. The through holes alternate with oxidized portions of the oxidized region along the line. Each barrier extends, as a whole, laterally across the second layer up to one of the lateral walls and delimits two sections of the second layer on each side of the barrier and on a same side of the microchannel.

A semiconductor oxide plate is formed on a recessed surface in a semiconductor matrix material layer. Comb structures are formed in the semiconductor matrix material layer. The comb structures include a pair of inner comb structures spaced apart by a first semiconductor portion. A second semiconductor portion that laterally surrounds the first semiconductor portion is removed selective to the comb structures using an isotropic etch process. The first semiconductor portion is protected from an etchant of the isotropic etch process by the semiconductor oxide plate, the pair of inner comb structures, and a patterned etch mask layer that covers the comb structures. A movable structure for a MEMS device is formed, which includes a combination of the first portion of the semiconductor matrix material layer and the pair of inner comb structures.

Provided is a gas sensor including a substrate, a first membrane disposed on the substrate, a heating structure disposed on the first membrane, a second membrane disposed on the heating structure, a sensing electrode disposed on the second membrane, and a sensing material structure disposed on the sensing electrode. Here, the substrate provides an isolation space defined by a recessed surface obtained as a portion of a top surface of the substrate is spaced downward from a bottom surface of the first membrane, and the first membrane provides a first membrane etching hole that vertically extends to connect a top surface and the bottom surface of the first membrane and is connected with the isolation space. Also, the first membrane etching hole has a diameter of about 3 μm to about 20 μm.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.

A piezoelectric microelectromechanical systems microphone is provided comprising a sensor, an anchor region at which the sensor is supported by a substrate, a first region of the sensor adjacent to the anchor region having a first compliance, the first region having at least one piezoelectric layer and at least one electrode, and a second region of the sensor, the second region being adjacent to the first region, having at least one piezoelectric layer and at least one electrode, and having a second compliance, the first and second compliances being different. A method for manufacturing a piezoelectric microelectromechanical systems microphone is also provided.

An ultrasonic transducer device includes a patterned film stack disposed on first regions of a substrate, the patterned film stack including a metal electrode layer and a bottom cavity layer formed on the metal electrode layer. The ultrasonic transducer device further includes a planarized insulation layer disposed on second regions of the substrate layer, a cavity formed in a membrane support layer and a CMP stop layer, the CMP stop layer including a top layer of the patterned film stack and the membrane support layer formed over the patterned film stack and the planarized insulation layer. The ultrasonic transducer device also includes a membrane bonded to the membrane support layer. The CMP stop layer underlies portions of the membrane support layer but not the cavity.