A microphone device comprises a microphone die including a first microphone motor and a second microphone motor, an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, and a sensor die stacked on top of the acoustic integrated circuit, wherein the sensor die comprises a pressure sensor. Another microphone comprises a microphone die including a first microphone motor and a second microphone motor and an integrated circuit die. The integrated circuit die comprises an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, a pressure sensor, and a pressure integrated circuit structured to press signals produced by the pressure sensor.

A capacitive pressure sensor for an internal combustion engine is provided having a housing having a bottom surface, variable capacitor and circuitry. The variable capacitor is formed by a stationary electrode and an elastically bendable electrode. Pressure exerted on the bottom surface acts to bend the elastically bendable electrode. This bending alters the capacitance of the variable capacitor. The circuitry is configured to generate a signal based on the variable capacitance of the variable capacitor. This capacitance is representative of the pressure exerted on the bottom surface.

A device for cavitation detection of a pure water hydraulic system based on pressure includes a chamber component; an inner diameter of the drainage nozzle gradually increases along an inflow direction of a liquid medium, so as to reduce a flow velocity of the liquid medium after being drained into the drainage nozzle; and the detection assembly includes a housing, one end of the housing facing the drainage nozzle is an open end, an elastic cover sheet is arranged in the open end, an electrode is arranged in the housing, diaphragms are respectively arranged on two sides of the electrode, and the electrode is closely attached to the elastic cover sheet through one of the diaphragms; the liquid medium is ejected from the drainage nozzle and impacts the elastic cover sheet.