MEMS Capacitive Sensing for Position Detection of Movable Objects

This paper presents a capacitive position detection system capable of determining the absolute position and rotation of electrically isolated objects. By implementing an array of micromachined mutual capacitance sensors, microscale displacements of the sensed object can be measured. This approach has the added benefit of low noise sensitivity and the ability to detect multiple objects simultaneously. The interactions between the sensed object and an individual capacitive sensor are modeled and compared with the results of both numerical and experimental testing. Based on the inferences made from the single sensor design, a model for the capacitive sensor array is presented. Initial experimental results demonstrate translational accuracy under 100µm for a 500µm by 500µm silicon chip on a fabricated sensor array with a 36% fill factor. Through further design optimization, the proposed array model shows that sub-micrometer, sub-degree accuracy can be achieved.

Author

• Reilly, Chris

Language

• en

Keyword

• Rotation measurement
• Capacitance
• Position measurement
• Capacitive sensors

Date created

• 2014

Type of Work

• Master's Thesis

License

• All rights reserved

Rights statement

• In Copyright

GW Unit

• Electrical Engineering

Degree

• M.S.

Advisor

• Zaghloul, Mona E
• Bedair, Sarah S

Committee Member(s)

• Ahmadi, Shahrokh

Persistent URL

•  https://scholarspace.library.gwu.edu/etd/z316q169v