The diaphragm in a MEMS (Micro-Electro-Mechanical Systems) microphone operates based on the principle of mechanical deformation in response to sound waves.
When sound waves reach the MEMS microphone, they exert pressure on the diaphragm. The diaphragm is a thin, flexible membrane that moves in response to these pressure variations.
As the diaphragm moves, it changes the distance between itself and a fixed backplate. This change in distance alters the capacitance between the diaphragm and the backplate.
The capacitance change is then converted into an electrical signal through an integrated circuit attached to the MEMS structure. This electrical signal represents the sound that was incident on the microphone.
For example, in a noisy environment, the diaphragm would vibrate rapidly in response to the complex sound waves, and the resulting electrical signal would accurately capture these variations.
In summary, the movement of the diaphragm and the subsequent conversion of mechanical motion into an electrical signal is the key mechanism by which a MEMS microphone detects and processes sound.