A significant increase in the demand of accelerometers is expected as the market for consumer electronics, such as smartphones, and social infrastructure monitoring applications are expanding.
Such miniaturized and mass-producible accelerometers are commonly developed by silicon MEMS technology where the fabrication process is well established.
In the design of accelerometers, there is a trade-off between the size reduction and the noise reduction because the mechanical noise dominated by the Brownian noise is inversely proportional to the mass of the moving electrode called as proof mass.
Moreover, as for capacitive accelerometers, the sensitivity is generally proportional to the accelerometer size, and thus there is also a trade-off between the size reduction and the sensitivity increase.
Since high-resolution accelerometers require low noise and high sensitivity performances, it has been difficult for conventional silicon-based MEMS accelerometers to detect 1 μG level input acceleration.
Low noise and high sensitivity MEMS accelerometer