Patent ID: 11906416
Assignee: STMICROELECTRONICS S.R.L.
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 20:
21. A method for sensing microparticles in an environment external to a MEMS sensing device, the method comprising:
during a first operative phase, applying electric signals to a piezoelectric element of a sensor to cause a membrane of the sensor to oscillate about an equilibrium position and at a resonance frequency, the resonance frequency depending on an amount of microparticles located on the membrane, wherein the sensor is integrated in a semiconductor body and includes a sensor cavity, wherein the membrane is suspended over the sensor cavity, and the piezoelectric element is located over the membrane, wherein the membrane includes a plurality of through holes configured to establish a fluid communication between the sensor cavity and the environment, and
using a pump integrated in the semiconductor body to cause air pressure in the sensor cavity to be reduced with respect to the air pressure of the environment during the first operative phase such that the microparticles are caused to adhere to the membrane by a suction force through the plurality of through holes, wherein the pump is adjacent to the sensor and is connected to the sensor through a duct in the semiconductor body.