World Applied Sciences Journal 26 (7): 950-956, 2013
ISSN 1818-4952
© IDOSI Publications, 2013
DOI: 10.5829/idosi.wasj.2013.26.07.1718
Corresponding Author: Hazian Mamat, Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan
Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
950
A COMSOL Model to Analyse the Structural Mechanical Problem in
an Electrostatically Controlled Prestressed Micro-Mirror
Hazian Mamat, Azrul Azlan Hamzah, Azman Jalar, Jumril Yunas and Nurfirdaus A. Rahim
1 1 1 1 2
Institute of Microengineering and Nanoelectronics (IMEN),
1
Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, MALAYSIA
MIMOS Berhad, Technology Park Malaysia, Bukit Jalil, 57000 Kuala Lumpur, MALAYSIA
2
Submitted: Oct 7, 2013; Accepted: Nov 10, 2013; Published: Nov 27, 2013
Abstract: In nowadays biomedical and industrial applications such as optical switch matrices, laser scanning
displays and biomedical imaging systems which are parts of theactuation and sensing components are realized
using micro-mirrors fabricated usingMicro Electro Mechanical Systems (MEMS) technology. This paper studies
through comsol model, the structural mechanical properties of the actuation mechanism of a square shape
micro-mirror with the lift-off of the structure used four springs simulating a prestressed cantilever beam [5].
There are few base materials were introduced such as Alumina, Aluminium 3003 H18, Aluminium 6063 T18,
Copper and Aluminium. To make the leg or cantilevermore efficient the structural steel was introduced together
with base materials listed above to further reduce the lift-off stress.
Key words: Micro-Mirror COMSOL Electrostatic driven
INTRODUCTION accomplished by using electrostatics, magnetic, thermal
In the last decades, the development of Micro Electro to Digital MicroMirror Device (DMD), an optical
Mechanical Systems (MEMS) technology shows a huge semiconductor which is the core of DLP projection
step forward in biomedical, automotiveand communication technologyinvented by Dr. Larry Hanbeck and Dr.
industries. By reducing mass and size of devices through William E “Ed Nelson” of Texas Instrument in1987 which
MEMS technology, the performances of bio chips, RF used Aluminium as mirror materials [2]. In this simulation,
devices, accelerometers and mass flow sensorswere we are going to shows how Aluminium and few other
improved greatly. The high demandof MEMS devices for materials performed as a micromirror with square shape
optical application are optical coherence tomography and supported by cantilever beam. The characteristics of
(OCT) for an endoscope,optical switch arrays for lift-off prestress and surface deformation wasalso studied.
communications, confocal laser scanning microscopy
(CLSM) and digital micro-mirror devices for Digital Micro Simulation Details: The simulation was done using
Device DMD. Micromirror devices are device based on COMSOL software, which was known as one of the
microscopically, commonly known assmall mirrorswhich software normally used to simulate all MEMS devices
it size in millimeters. These mirrors used Micro Electro prior to fabrication steps. There are also other software
Mechanical System (MEMS), by means that their states such as COVENTOR and etc. Prior to start the simulation,
are controlled by applying a voltage between the two the materials for micromirror was studied and selected.
electrodes around the mirror arrays [1]. Electrostatic also Among the available materials in the COMSOL library,
controlled micro-mirror. It is typically quite small and the selected one are presented in Table 1 below. In the
arrays of such devices can be implemented in a projection simulation, the model used was selected from one of
system. They serve as optical redirectors and similar available tutorials in COMSOL [5]. In this simulation the
reflection devices, refer to Pic. 1 and Pic 2 for product Initial Press was set at 5 GPa, which wasadvised from
application.The actuation of MEMS micro-mirror can be comsol proposed value.
or piezo-electric mechanism.The research was referring