Quantum mechanics

Spring (device)

Engineering

Capacitance

Microelectromechanical systems

Materials science

Operating system

Computer science

Acoustics

Linearity

Accelerometer

Capacitive sensing

Physics

Image (mathematics)

Electronic engineering

Noise floor

Artificial intelligence

Noise measurement

Sensitivity (control systems)

Structural engineering

Electrode

Noise reduction

Noise (video)

Optoelectronics

Dynamic range

Electrical engineering

Sensors and Actuators A Physical

This work reports a capacitive MEMS accelerometer designed for seismic applications. The asymmetrical anti-spring structure is used and the device is microfabricated using SOI technology. Two capacitive readout methods, namely, capacitance-to-voltage-converter (CVC) and a commercial sigma-delta modulator, are introduced for comparison in the device characterization. For both methods, the accelerometer has a frequency dynamic range of 0-158 Hz. The sensitivity and non-linearity of the sensor is 53 fF/g (21.3 mV/g), 0.03% by the sigma-delta modulator, while the CVC method is 3.78 mV/g with the non-linearity 0.04%. As for the resolution, both methods have detected the lab's background noise of 11.5 μg/Hz at 0.03 Hz and have exhibited the resolution of the sensor is better than 10 μg/Hz. Regardless of the difference in parameter selection for the circuits, the CVC method has a much lower noise floor (51.8 ng/Hz at 1 Hz) than sigma-delta readout configuration (10 μg/Hz at 1 Hz). The proposed MEMS accelerometer based on anti-spring structures shows its high sensitivity and low noise performance, demonstrating its potential in seismic applications.

A low noise capacitive MEMS accelerometer with anti-spring structure