Resonant accelerometer, Silicon Oscillating Accelerometer, referred to as SOA.
The sound frequency of a string is different when the tension is different. The principle of the resonant accelerometer is the same. The vibration beam is fixed at one end and connected to a mass at the other end. When there is acceleration in the vibration beam axis direction, the beam will be subjected to axial force. The tension in the beam changes, and its natural frequency changes accordingly. If a certain excitation is applied to the beam, its natural frequency can be measured by detecting its response, and then the acceleration can be measured. The application of excitation and the detection of response are usually achieved by a comb mechanism.
The characteristic of SOA is that it reflects the change of acceleration by changing the characteristics of the second-order system itself, which is different from the accelerometers of capacitive type, piezoelectric type and optical waveguide type.
The common structures of SOA include S structure and double-ended tuning fork (DETF). The schematic diagram of the S structure is shown in the following figure. The DEFT type is to add a set of mechanisms symmetrical to the left side of the other half of the mass. DEFT is currently the mainstream structure of SOA.
If you want to get more details about accelerometer,pls visit https://www.ericcointernational.com/accelerometer/