Abstract
This paper presents design optimization, numerical modelling, fabrication and characterization of a single-axis comb drive MEMS gap-changeable differential capacitive accelerometer with a compact footprint of 2 mm × 2 mm. High sensitivity is achieved by optimizing the ratio of the anti-finger gap to finger gap spacing. It is found that a gap ratio of 3.44 leads to a displacement sensitivity of 0.0139 µm/g and a capacitive sensitivity of 80 fF/g. Finite element analysis is used to find the mode shape and frequency. Scanning electron microscope and capacitance-voltage measurements are employed to confirm the devices work. An enlarged static capacitance of 14.46 ± 0.42 pF is measured due to the enlarged stator anchor width. Electrical sensitivity of 35.93 mV/g is obtained by using the capacitance readout circuit at the system level, and the electrical sensitivity is practically constant over the frequency range of 100–200 Hz.
Original language | English (US) |
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Article number | 108377 |
Journal | Measurement: Journal of the International Measurement Confederation |
Volume | 169 |
DOIs | |
State | Published - Feb 2021 |
Keywords
- Accelerometer
- Anti-gap spacing
- Capacitive sensitivity
- Comb fingers
- MEMS
ASJC Scopus subject areas
- Instrumentation
- Electrical and Electronic Engineering