In one aspect, a MEMS transducer, in particular a MEMS sound transducer unit, preferably for generating and/or detecting sound waves in the audible wavelength spectrum and/or in the ultrasonic range, includes a carrier and at least one piezoelectric element. The at piezoelectric element(s) is arranged on the carrier and is deflectable in the direction of a stroke axis, with the piezoelectric element(s) having at least two piezoelectric layers and at least one carrier layer. By means of the at least two piezoelectric layers, electrical signals and deflections of the piezoelectric element(s) can be converted from one into the other. Additionally, the carrier layer is arranged between two piezoelectric layers in the direction of the stroke axis.

A method of fabricating one or more glass cells includes drawing one or more glass capillaries from a source of glass material. The method includes performing a first conditioning of one or more inner surfaces of the one or more capillaries. The method includes sealing one or more first ends of the one or more capillaries using thermal energy. The method includes performing a second conditioning of the one or more inner surfaces after the sealing. The method includes purifying the one or more capillaries to increase a purity of a gas used to fill the one or more capillaries. The method includes filling the one or more capillaries using the gas after the purifying. The method includes pressurizing the one or more capillaries to a given pressure. The method includes sealing one or more second ends of the one or more capillaries using thermal energy.

An electrostatic MEMS transducer includes a membrane and an actuator array. The actuator array includes a plurality of vertical parallel-plate actuator cells. Each vertical actuator cell comprises two silicon electrodes and a polysilicon electrode positioned between the two silicon electrodes. The actuator cells are configured to generate oscillation of the membrane responsive to an electrical signal.

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 pressure sensor. The pressure sensor has a sensing region and a non-sensing region, and includes: a first flexible film layer, wherein a first groove is disposed in a first surface of the first flexible film layer, and the first groove is within the sensing region; a first electrode layer; a first insulative layer, disposed on a side, distal from the first flexible film layer, of the first electrode layer; a second electrode layer, wherein the second electrode layer is disposed on a side, distal from the first flexible film layer, of the first insulative layer; and a second flexible film layer, wherein the second flexible film layer is disposed on a side, distal from the first flexible film layer, of the second electrode layer.