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High performance 3-folded symmetric decoupled MEMS gyroscopes
This thesis reports, for the first time, on a novel design and architecture for realizing inertial grade gyroscope based on Micro-Electro-Mechanical Systems (MEMS) technology. The proposed device is suitable for high-precision Inertial Navigation Systems (INS). The new design has been investigated a...
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2013
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| _version_ | 1867613417329655808 |
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| access_status_str | Open Access |
| author | Tawfik, Hani Hisham |
| author_browse | Tawfik, Hani Hisham |
| author_facet | Tawfik, Hani Hisham |
| author_sort | Tawfik, Hani Hisham |
| collection | Thesis |
| dc_rights_str_mv | The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. |
| description | This thesis reports, for the first time, on a novel design and architecture for realizing inertial grade gyroscope based on Micro-Electro-Mechanical Systems (MEMS) technology. The proposed device is suitable for high-precision Inertial Navigation Systems (INS). The new design has been investigated analytically and numerically by means of Finite Element Modeling (FEM) of the shapes, resonance frequencies and decoupling of the natural drive and sense modes of the various implementations. Also, famous phenomena known as spring softening and spring hardening are studied. Their effect on the gyroscope operation is modeled numerically in Matlab/Simulink platform. This latter model is used to predict the drive/sense mode matching capability of the proposed designs. Based on the comparison with the best recently reported performance towards inertial grade operation, it is expected that the novel architecture further lowers the dominant Brownian (thermo-mechanical) noise level by more than an order of magnitude (down to 0.08º/hr). Moreover, the gyroscope's figure of merit, such as output sensitivity (150 mV/º/s), is expected to be improved by more than two orders of magnitude. This necessarily results in a signal to noise ratio (SNR) which is up to three orders of magnitude higher (up to 1,900mV/ º/hr). Furthermore, the novel concept introduced in this work for building MEMS gyroscopes allows reducing the sense parasitic capacitance by up to an order of magnitude. This in turn reduces the drive mode coupling or quadrature errors in the sensor's output signal. The new approach employs Silicon-on-Insulator (SOI) substrates that allows the realization of large mass (>1.6mg), large sense capacitance (>2.2pF), high quality factors (>21,000), large drive amplitude (~2-4 µm) and low resonance frequency (~3-4 KHz) as well as the consequently suppressed noise floor and reduced support losses for high-performance vacuum operation. Several challenges were encountered during fabrication that required developing high aspect ratio (up to 1:20) etching process for deep trenches (up to 500 µm). Frequency Response measurement platform was built for devices characterization. The measurements were performed at atmospheric pressures causing huge drop of the devices performance. Therefore, various MEMS gyroscope packaging technologies are studied. Wafer Level Packaging (WLP) is selected to encapsulate the fabricated devices under vacuum by utilizing wafer bonding. Through Silicon Via (TSV) technology was developed (as connections) to transfer the electrical signals (of the fabricated devices) outside the cap wafers. |
| format | Thesis |
| id | oai:fount.aucegypt.edu:etds-2280 |
| institution | American University in Cairo (Egypt) |
| last_indexed | 2026-06-10T12:35:48.888Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from AUC Knowledge Fountain — bepress |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | AUC Knowledge Fountain |
| publisherStr | AUC Knowledge Fountain |
| record_format | dspace |
| source_str | AUC Knowledge Fountain — bepress |
| spelling | oai:fount.aucegypt.edu:etds-2280 High performance 3-folded symmetric decoupled MEMS gyroscopes Tawfik, Hani Hisham This thesis reports, for the first time, on a novel design and architecture for realizing inertial grade gyroscope based on Micro-Electro-Mechanical Systems (MEMS) technology. The proposed device is suitable for high-precision Inertial Navigation Systems (INS). The new design has been investigated analytically and numerically by means of Finite Element Modeling (FEM) of the shapes, resonance frequencies and decoupling of the natural drive and sense modes of the various implementations. Also, famous phenomena known as spring softening and spring hardening are studied. Their effect on the gyroscope operation is modeled numerically in Matlab/Simulink platform. This latter model is used to predict the drive/sense mode matching capability of the proposed designs. Based on the comparison with the best recently reported performance towards inertial grade operation, it is expected that the novel architecture further lowers the dominant Brownian (thermo-mechanical) noise level by more than an order of magnitude (down to 0.08º/hr). Moreover, the gyroscope's figure of merit, such as output sensitivity (150 mV/º/s), is expected to be improved by more than two orders of magnitude. This necessarily results in a signal to noise ratio (SNR) which is up to three orders of magnitude higher (up to 1,900mV/ º/hr). Furthermore, the novel concept introduced in this work for building MEMS gyroscopes allows reducing the sense parasitic capacitance by up to an order of magnitude. This in turn reduces the drive mode coupling or quadrature errors in the sensor's output signal. The new approach employs Silicon-on-Insulator (SOI) substrates that allows the realization of large mass (>1.6mg), large sense capacitance (>2.2pF), high quality factors (>21,000), large drive amplitude (~2-4 µm) and low resonance frequency (~3-4 KHz) as well as the consequently suppressed noise floor and reduced support losses for high-performance vacuum operation. Several challenges were encountered during fabrication that required developing high aspect ratio (up to 1:20) etching process for deep trenches (up to 500 µm). Frequency Response measurement platform was built for devices characterization. The measurements were performed at atmospheric pressures causing huge drop of the devices performance. Therefore, various MEMS gyroscope packaging technologies are studied. Wafer Level Packaging (WLP) is selected to encapsulate the fabricated devices under vacuum by utilizing wafer bonding. Through Silicon Via (TSV) technology was developed (as connections) to transfer the electrical signals (of the fabricated devices) outside the cap wafers. 2013-02-01T08:00:00Z thesis application/pdf https://fount.aucegypt.edu/etds/1281 https://fount.aucegypt.edu/context/etds/article/2280/viewcontent/Thesis.pdf The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. Theses and Dissertations AUC Knowledge Fountain MEMS MEMS Packaging |
| spellingShingle | MEMS MEMS Packaging Tawfik, Hani Hisham High performance 3-folded symmetric decoupled MEMS gyroscopes |
| title | High performance 3-folded symmetric decoupled MEMS gyroscopes |
| title_full | High performance 3-folded symmetric decoupled MEMS gyroscopes |
| title_fullStr | High performance 3-folded symmetric decoupled MEMS gyroscopes |
| title_full_unstemmed | High performance 3-folded symmetric decoupled MEMS gyroscopes |
| title_short | High performance 3-folded symmetric decoupled MEMS gyroscopes |
| title_sort | high performance 3 folded symmetric decoupled mems gyroscopes |
| topic | MEMS MEMS Packaging |
| url | https://fount.aucegypt.edu/etds/1281 https://fount.aucegypt.edu/context/etds/article/2280/viewcontent/Thesis.pdf |
| work_keys_str_mv | AT tawfikhanihisham highperformance3foldedsymmetricdecoupledmemsgyroscopes |