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Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor

Magnetic field sensors are becoming an essential part of everyday life due to the improvements in their sensitivities and resolutions, while at the same time they have become compact, smaller in size and economical. In the work presented herein a Lorentz force based CMOS-MEMS magnetic field sensor i...

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Autores principales: Dennis, John Ojur, Ahmad, Farooq, Khir, M. Haris Bin Md, Hamid, Nor Hisham Bin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4570319/
https://www.ncbi.nlm.nih.gov/pubmed/26225972
http://dx.doi.org/10.3390/s150818256
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author Dennis, John Ojur
Ahmad, Farooq
Khir, M. Haris Bin Md
Hamid, Nor Hisham Bin
author_facet Dennis, John Ojur
Ahmad, Farooq
Khir, M. Haris Bin Md
Hamid, Nor Hisham Bin
author_sort Dennis, John Ojur
collection PubMed
description Magnetic field sensors are becoming an essential part of everyday life due to the improvements in their sensitivities and resolutions, while at the same time they have become compact, smaller in size and economical. In the work presented herein a Lorentz force based CMOS-MEMS magnetic field sensor is designed, fabricated and optically characterized. The sensor is fabricated by using CMOS thin layers and dry post micromachining is used to release the device structure and finally the sensor chip is packaged in DIP. The sensor consists of a shuttle which is designed to resonate in the lateral direction (first mode of resonance). In the presence of an external magnetic field, the Lorentz force actuates the shuttle in the lateral direction and the amplitude of resonance is measured using an optical method. The differential change in the amplitude of the resonating shuttle shows the strength of the external magnetic field. The resonance frequency of the shuttle is determined to be 8164 Hz experimentally and from the resonance curve, the quality factor and damping ratio are obtained. In an open environment, the quality factor and damping ratio are found to be 51.34 and 0.00973 respectively. The sensitivity of the sensor is determined in static mode to be 0.034 µm/mT when a current of 10 mA passes through the shuttle, while it is found to be higher at resonance with a value of 1.35 µm/mT at 8 mA current. Finally, the resolution of the sensor is found to be 370.37 µT.
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spelling pubmed-45703192015-09-17 Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor Dennis, John Ojur Ahmad, Farooq Khir, M. Haris Bin Md Hamid, Nor Hisham Bin Sensors (Basel) Article Magnetic field sensors are becoming an essential part of everyday life due to the improvements in their sensitivities and resolutions, while at the same time they have become compact, smaller in size and economical. In the work presented herein a Lorentz force based CMOS-MEMS magnetic field sensor is designed, fabricated and optically characterized. The sensor is fabricated by using CMOS thin layers and dry post micromachining is used to release the device structure and finally the sensor chip is packaged in DIP. The sensor consists of a shuttle which is designed to resonate in the lateral direction (first mode of resonance). In the presence of an external magnetic field, the Lorentz force actuates the shuttle in the lateral direction and the amplitude of resonance is measured using an optical method. The differential change in the amplitude of the resonating shuttle shows the strength of the external magnetic field. The resonance frequency of the shuttle is determined to be 8164 Hz experimentally and from the resonance curve, the quality factor and damping ratio are obtained. In an open environment, the quality factor and damping ratio are found to be 51.34 and 0.00973 respectively. The sensitivity of the sensor is determined in static mode to be 0.034 µm/mT when a current of 10 mA passes through the shuttle, while it is found to be higher at resonance with a value of 1.35 µm/mT at 8 mA current. Finally, the resolution of the sensor is found to be 370.37 µT. MDPI 2015-07-27 /pmc/articles/PMC4570319/ /pubmed/26225972 http://dx.doi.org/10.3390/s150818256 Text en © 2015 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Dennis, John Ojur
Ahmad, Farooq
Khir, M. Haris Bin Md
Hamid, Nor Hisham Bin
Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor
title Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor
title_full Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor
title_fullStr Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor
title_full_unstemmed Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor
title_short Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor
title_sort optical characterization of lorentz force based cmos-mems magnetic field sensor
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4570319/
https://www.ncbi.nlm.nih.gov/pubmed/26225972
http://dx.doi.org/10.3390/s150818256
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AT hamidnorhishambin opticalcharacterizationoflorentzforcebasedcmosmemsmagneticfieldsensor