This thesis presents a surface micromachining process to fabricate scratch drive actuator (SDA). Besides, various parameters (plate length, plate width, plate shapes, support beam width, spring type, one-plate SDA/four-plate SDA, dimple number, bushing length and etching hole¡Ketc.) have been designed to find appropriate design parameters of the SDA and to reduce the driving-voltage. According to the results, we can demonstrate three points below: (i) Adding etching holes at the end of plate can reduce residual electric charge and increase life time of SDA. (ii) Changing normal wafer for low resistance wafer can reduce the driving-voltage of SDA about 35%. (iii) The life time of triangle SDA is longer than those of other plate shapes. Finally, discussions and suggestions for the design of SDA are presented in this thesis.

Includes bibliographical references (p. 78-89).

No description available.

Thesis (M.S.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 3, 2008) Includes bibliographical references (p. 66-74).

Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Dr. Steven Y. Liang; Committee Member: Dr. Chen Zhou; Committee Member: Dr. Paul Griffin; Committee Member: Dr. Shreyes N. Melkote; Committee Member: Dr. Steven Danyluk.

Thesis (Ph.D.) - Simon Fraser University, 2004. / Theses (School of Engineering Science) / Simon Fraser University.

There is growing demand for micro and meso scale devices with applications in the field of optics, semiconductor and bio-medical fields. In response to this demand, mechanical micro-cutting (e.g. micro-milling) is emerging as a viable alternative to lithography based micromachining techniques. Mechanical micromachining methods are capable of generating three-dimensional free-form surfaces to sub-micron level precision and micron level accuracies in a wide range of materials including common engineering alloys. However, certain factors limit the types of workpiece materials that can be processed using mechanical micromachining methods. For difficult-to-machine materials such as tool and die steels, limited machine-tool system stiffness and low tool flexural strength are major impediments to the use of mechanical micromachining methods. This thesis presents the design, fabrication and analysis of a novel Laser-assisted Mechanical Micromachining (LAMM) process that has the potential to overcome these limitations. The basic concept involves creating localized thermal softening of the hard material by focusing a solid-state continuous wave laser beam of diameter ranging from 70-120 microns directly in front of a miniature (300 microns-1 mm wide) cutting tool. By suitably controlling the laser power, spot size and speed, it is possible to produce a sufficiently large decrease in flow stress of the work material and, consequently, the cutting forces. This in turn will reduce machine/tool deflection and chances of catastrophic tool failure. The reduced machine/tool deflection yields improved accuracy in the machined feature. In order to use this process effectively, adequate thermal softening needs to be produced while keeping the heat affected zone in the machined surface to a minimum. This has been accomplished in the thesis via a detailed process characterization, modeling of process mechanics and optimization of process variables.

This paper discusses basic issues of micromachined ultrasonic transducers, including their design and fabrication. First, the acoustic fundamentals of ultrasonic transducers are introduced, and relevant simulation methods are illustrated. Following these topics, important aspects of silicon micromachining are presented. Based on this knowledge, two distinctive micromachining processes for transducer fabrication are proposed. One of them, the bulk process, has been proved to be successful, whereas for the second one, a surface process, some improvements are still needed. Besides these works, an innovative direct bonding technology is also developed. This technology constitutes the basis of the bulk process. Of course, it can also be used for the packaging of other MEMS devices.

TiN is used commercially as a wear resistant coating on cutting tools and as a diffusion barrier in microelectronics. TiN has gained increased interest as a material for MEMS, however there has been very little work carried out in the area of patterning and releasing TiN for use as a structural MEMS material. This thesis presents an investigation into the patterning and release of filtered arc deposited TiN thin films using surface micromachining techniques. Two novel strategies are presented for patterning TiN thin films and are achieved using excimer laser micromachining and photolithographic wet-etching. TiN was deposited onto single crystal Si and Cr and Cu sacrificial layers on Si. The use of Cr as a sacrificial layer was found to facilitate the best quality patterning of the TiN and hence the majority of the work involved using Cr sacrificial layers. TiN was deposited using partial filtration and full filtration and differences in the ability to selectively laser pattern the TiN from the Cr sacrificial layer are presented. Various analytical techniques were employed to investigate the origin of the difference in laser patterning the TiN thin films. The establishment of TiN and Cr as a novel material combination for surface micromachined MEMS was extended by etching the Cr sacrificial layer to facilitate the release of TiN stress-measurement structures. The major finding of this thesis is that filtered arc deposited TiN thin film on Cr can be used as a material combination to surface micromachine freestanding TiN structures as high quality patterning and etch selectivity can be achieved using both excimer laser micromachining and photolithographic wet-etching.