Movable MEMS Devices on Flexible Silicon

Handle URI:
http://hdl.handle.net/10754/290920
Title:
Movable MEMS Devices on Flexible Silicon
Authors:
Ahmed, Sally
Abstract:
Flexible electronics have gained great attention recently. Applications such as flexible displays, artificial skin and health monitoring devices are a few examples of this technology. Looking closely at the components of these devices, although MEMS actuators and sensors can play critical role to extend the application areas of flexible electronics, fabricating movable MEMS devices on flexible substrates is highly challenging. Therefore, this thesis reports a process for fabricating free standing and movable MEMS devices on flexible silicon substrates; MEMS flexure thermal actuators have been fabricated to illustrate the viability of the process. Flexure thermal actuators consist of two arms: a thin hot arm and a wide cold arm separated by a small air gap; the arms are anchored to the substrate from one end and connected to each other from the other end. The actuator design has been modified by adding etch holes in the anchors to suit the process of releasing a thin layer of silicon from the bulk silicon substrate. Selecting materials that are compatible with the release process was challenging. Moreover, difficulties were faced in the fabrication process development; for example, the structural layer of the devices was partially etched during silicon release although it was protected by aluminum oxide which is not attacked by the releasing gas . Furthermore, the thin arm of the thermal actuator was thinned during the fabrication process but optimizing the patterning and etching steps of the structural layer successfully solved this problem. Simulation was carried out to compare the performance of the original and the modified designs for the thermal actuators and to study stress and temperature distribution across a device. A fabricated thermal actuator with a 250 μm long hot arm and a 225 μm long cold arm separated by a 3 μm gap produced a deflection of 3 μm before silicon release, however, the fabrication process must be optimized to obtain fully functioning devices on flexible silicon.
Advisors:
Hussain, Muhammad Mustafa ( 0000-0003-3279-0441 )
Committee Member:
Alouini, Mohamed-Slim ( 0000-0003-4827-1793 ) ; Wang, Peng ( 0000-0003-0856-0865 )
KAUST Department:
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Program:
Electrical Engineering
Issue Date:
5-May-2013
Type:
Thesis
Appears in Collections:
Theses; Electrical Engineering Program; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.advisorHussain, Muhammad Mustafaen
dc.contributor.authorAhmed, Sallyen
dc.date.accessioned2013-05-13T09:19:57Z-
dc.date.available2013-05-13T09:19:57Z-
dc.date.issued2013-05-05en
dc.identifier.urihttp://hdl.handle.net/10754/290920en
dc.description.abstractFlexible electronics have gained great attention recently. Applications such as flexible displays, artificial skin and health monitoring devices are a few examples of this technology. Looking closely at the components of these devices, although MEMS actuators and sensors can play critical role to extend the application areas of flexible electronics, fabricating movable MEMS devices on flexible substrates is highly challenging. Therefore, this thesis reports a process for fabricating free standing and movable MEMS devices on flexible silicon substrates; MEMS flexure thermal actuators have been fabricated to illustrate the viability of the process. Flexure thermal actuators consist of two arms: a thin hot arm and a wide cold arm separated by a small air gap; the arms are anchored to the substrate from one end and connected to each other from the other end. The actuator design has been modified by adding etch holes in the anchors to suit the process of releasing a thin layer of silicon from the bulk silicon substrate. Selecting materials that are compatible with the release process was challenging. Moreover, difficulties were faced in the fabrication process development; for example, the structural layer of the devices was partially etched during silicon release although it was protected by aluminum oxide which is not attacked by the releasing gas . Furthermore, the thin arm of the thermal actuator was thinned during the fabrication process but optimizing the patterning and etching steps of the structural layer successfully solved this problem. Simulation was carried out to compare the performance of the original and the modified designs for the thermal actuators and to study stress and temperature distribution across a device. A fabricated thermal actuator with a 250 μm long hot arm and a 225 μm long cold arm separated by a 3 μm gap produced a deflection of 3 μm before silicon release, however, the fabrication process must be optimized to obtain fully functioning devices on flexible silicon.en
dc.language.isoenen
dc.subjectMovableen
dc.subjectMEMSen
dc.subjectSiliconen
dc.subjectFlexibleen
dc.subjectSubstratesen
dc.subjectActuatorsen
dc.titleMovable MEMS Devices on Flexible Siliconen
dc.typeThesisen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberAlouini, Mohamed-Slimen
dc.contributor.committeememberWang, Pengen
thesis.degree.disciplineElectrical Engineeringen
thesis.degree.nameMaster of Scienceen
dc.person.id118409en
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