A small cavity for detecting sound-induced flow.

Area of Science:

• Acoustics
• Microfabrication
• Sensor Technology

Background:

• Silicon microphones are mass-produced using microfabrication.
• The primary component is the cavity behind the diaphragm.
• Understanding acoustic particle velocity in cavities is crucial.

Purpose of the Study:

• To develop an acoustic flow sensor compatible with silicon microfabrication.
• To minimize design departures from existing silicon microphones.
• To study acoustic particle velocity within a planar surface cavity.

Main Methods:

• Investigated acoustic particle velocity in a planar surface cavity.
• Developed a simple analytical model for cavity dimensions.
• Utilized finite element modeling for detailed analysis.
• Conducted experimental measurements of acoustic particle velocity.

Main Results:

• Demonstrated inward and outward acoustic particle velocity flow within a single cavity.
• Cavity dimensions were estimated using an analytical model.
• Experimental measurements closely matched analytical and finite element models.
• Validated the acoustic flow sensing mechanism.

Conclusions:

• The proposed cavity design effectively directs acoustic particle velocity.
• This approach simplifies the design and fabrication of acoustic flow sensors.
• The method is compatible with existing silicon microfabrication processes.