High-Sensitivity Encoder-Like Micro Area-Changed Capacitive Transducer for a Nano-g Micro Accelerometer
| Autor: | Wenjie Wu, Liang-Cheng Tu, Ji Fan, J. Q. Liu, Pan-Pan Zheng, Huafeng Liu, Zhu Li |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
parasitic capacitance capacitive sensor area-changed fringe effect sensitivity improvement micro accelerometer Capacitive sensing Acoustics 02 engineering and technology Accelerometer lcsh:Chemical technology 01 natural sciences Biochemistry Capacitance Article Analytical Chemistry law.invention Parasitic capacitance law 0103 physical sciences lcsh:TP1-1185 Electrical and Electronic Engineering Instrumentation 010302 applied physics business.industry Dynamic range Electrical engineering 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics Capacitor Transducer 0210 nano-technology business Position sensor |
| Zdroj: | Sensors; Volume 17; Issue 9; Pages: 2158 Sensors, Vol 17, Iss 9, p 2158 (2017) Sensors (Basel, Switzerland) |
| ISSN: | 1424-8220 |
| DOI: | 10.3390/s17092158 |
| Popis: | Encoder-like micro area-changed capacitive transducers are advantageous in terms of their better linearity and larger dynamic range compared to gap-changed capacitive transducers. Such transducers have been widely applied in rectilinear and rotational position sensors, lab-on-a-chip applications and bio-sensors. However, a complete model accounting for both the parasitic capacitance and fringe effect in area-changed capacitive transducers has not yet been developed. This paper presents a complete model for this type of transducer applied to a high-resolution micro accelerometer that was verified by both simulations and experiments. A novel optimization method involving the insertion of photosensitive polyimide was used to reduce the parasitic capacitance, and the capacitor spacing was decreased to overcome the fringe effect. The sensitivity of the optimized transducer was approximately 46 pF/mm, which was nearly 40 times higher than that of our previous transducer. The displacement detection resolution was measured as 50 pm/√Hz at 0.1 Hz using a precise capacitance detection circuit. Then, the transducer was applied to a sandwich in-plane micro accelerometer, and the measured level of the accelerometer was approximately 30 ng/√Hz at 1Hz. The earthquake that occurred in Taiwan was also detected during a continuous gravity measurement. |
| Databáze: | OpenAIRE |
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