**7. Acknowledgment**

The author wants to thank Prof. Dr. Hiroyuki Fujita and Prof. Dr. Hiroshi Toshiyoshi (both are with the University of Tokyo, Japan) for their advisory helps. The author also wants to thank Kuan-Hsun Liao, Sheng-An Kuo, and Chung-Yuan Yang for their lab works. The related works were partially supported by the following projects:

National Science Council (NSC) of Taiwan (Republic of China)

Possibilities for Flexible MEMS:Take Display Systems as Examples 413

Leech, P, W., & Lee, R. A. (2007). *Hot Embossing of Diffractive Optically Variable Images in* 

Lin, S, C., Lee, S, L., & Yang, C, L. (2009). *Spectral Filtering of Multiple Directly Modulated* 

Lo, C., Huttunen, O, –H., Petäjä, J., Hast, J., Maaninen, A., Kopola, Fujita, H., & Toshiyoshi,

Marques, A., Moreno, I., Campos, J., & Yzuel, M, J. (2006). *Analysis of Fabry-Perot Interference* 

Matsumoto, S. (1990). *Electronic Display Devices*, John Wiley & Sons, Inc., ISBN 0-471-92218-8,

Obata, K., Sugioka, K., Shimazawa, N., & Midorikawa, K. (2006). *Fabrication of Microchip* 

Oh, H, –Y., Lee, C., & Lee, S. (2009). *Efficient Blue Organic Light-Emitting Diodes Using Newly-*

Pollack, M, G., Fair, R, B., & Shenderov, A, D. (2000). *Electrowetting-based Actuation of Liquid* 

Puetz, J., & Aegerter, M. A. (2008). *Direct Gravure Printing of Indium Tin Oxide Nanoparticle Patterns on Polymer Foils*, Thin Solid Films, Vol. 561, pp. 4495-4501, ISSN 0040-6090 Schanda, J. (2007). *Colorimetry*, John Wiley & Sons, Inc., ISBN 978-0-470-04904-4, New Jersey,

Senda, K., Bae, B, S., & Esashi, M. (2008). *MEMS Membrane Switches Backplane for Matrix* 

Senturia, S, D. (2001). *Microsystem Design*, Kluwer Academic Publishers, ISBN 0-306-47601-0,

Smith, F, G. (2007). *Optics and Photonics*, John Wiley & Sons, Ltd., ISBN 978-0470017845,

Taii, Y., Higo, A., Fujita, H., & Toshiyoshi, H. (2006). *A Transparent Sheet Display by Plastic* 

Vidotti, M., & Córdoba de Torresi, S, I. *(2008). Nanochromics: Old Materials, New Structures* 

Communications, Vol. 265, Iss. 1, pp. 84-94, ISSN 0030-4018

Applied physics A, Vol. 84, pp. 251-255, ISSN 0947-8396

Vol. 2, pp. 1349-1352, Niigata, Japan, December 3-5, 2008

Taii, Y. (2006). Master's degree thesis, The university of Tokyo

*Society,* Vol. 19, No. 7, pp. 1248-1257, ISSN 0103-5053

(September 2000), pp. 1725-1726, ISSN 0003-6951

Networking, Vol. 8, Iss. 3, (March 2009), pp. 308-316, ISSN 1943-0620 Lo, C., Huttunen, Hiitola-Keinänen, O. –H., Petäjä, J., Hast, J., Maaninen, A., Kopola, H.,

1353-1356, Niigata, Japan, December 3-5, 2008

ISSN 0167-9317

Japan, December 5-7, 2007

1, pp. 163-169, ISSN 1566-1199

New York, USA

USA

Massachusetts, USA

Chichester, England

1071-0922

*Biaxially-Oriented Polypropylene*, Microelectronic Engineering, Vol. 84, pp. 25-30,

*Channels for WDM Access Networks by Using an FP Etalon*, Journal of Optical

Fujita, H., & Toshiyoshi, H. (2008). *Active Matrix Flexible Display Array Fabricated by MEMS Printing Techniques*, Proceedings of The 15th Int. Display Workshop, pp.

H. (2007). *Novel Printing Processes for MEMS Fabry-perot Display Pixel*, Proceedings of The 14th Int. Display Workshop, pp. 1337-1340, ISBN 9781605603919, Sapporo,

*Effects on The Modulation Properties of Liquid Crystal Displays*, Optics

*Based on UV Transparent Polymer for DNA Electrophoresis by F2 Laser Ablation*,

*Developed Pyrene-Based Electron Transport Materials*, Organic Electronics, Vol. 10, Iss.

*Droplets for Microfluidic Applications*, Applied Physics Letters, Vol. 77, No. 11,

*Driven Large Sign Display*, Proceedings of The 15th International Display Workshops,

*MEMS*, Journal of Society for Information Display, Vol. 14, Iss. 8, pp. 735-741, ISSN

*and Architectures for High Performance Devices*, Journal of the Brazilian *Chemical* 

Research project (ID: 99-2218-E-007-018-MY2),

New Energy and Industrial Technology Development Organization (NEDO) of Japan

Industrial Technology Research Grant Program (ID: 06D48522d),

Japan Society for the Promotion of Science (JSPS)

International Training Program (ITP),

Finnish Funding Agency for Technology and Innovations (TEKES)

Funding decision 40104/07.

#### **8. References**


Abe, T., Yamashita, J., Shibata, H., Kato, Y., Matsumoto, H., & Iijama, T. (2008). *High-*

Author, G., & Martin, B. (1996). *Investigation of Photoresist-Specific Optical Proximity Effect*, Microelectronic Engineering, Vol. 30, Iss. 1-4, pp. 133-136, ISSN 0167-9317 Blanchet, G, B., Loo, Y., Rogers, J, A., Gao, F., & Fincher, C. R. (2003). *Large Area, High* 

Physics Letters, Vol. 82, No. 3, (January 2003), pp. 463-465, ISSN 0003-6951 Blanchet, G., & Rogers, J. (2003). *Printing Techniques for Plastic Electronics", Journal of Imaging* 

Boer, W, den. (2005). *Active Matrix Liquid Crystal Displays*, Elsevier Inc., ISBN 978-0-7506-

Bogacz, S., & Trafton, J, G. (2005). *Understanding Dynamic and Static Displays*, Cognitive Systems Research, Vol. 6, Iss. 4, (January 2005), pp. 312-319, ISSN 1389-0417 Corr, D., Bach, U., Fay, D., Kinsella, M., McAtamney, C., O'Reilly, F., Rao, S.N., & Stobie, N.

Crawford, G, P. (2005). *Flexible Flat Panel Displays*, John Wiley & Sons, Ltd., ISBN 978-0-470-

Crowley, J, M., Sheridon, N, K., & Romano, L. (2002). *Dipole Moments of Gyricon Balls*,

Cummins, D., Boschloo, G., Ryan, M., Corr, D., Rao, S, N., & Fitzmaurice, D. (2000). *Ultrafast* 

Hernandez, G. (1988). *Fabry-perot Interferometer*, Cambridge University Press, ISBN 0-521-

Ida, N. (2004). *Engineering Eletromagnetics*, Springer-verlag New York, LLC., ISBN 0-387-

Johnson, M, T., Zhou, G., Zehner, R., Amundson, K., Henzen, A., & Van de Kamer, J. (2006).

Kim, J., Yang, K., Hong, S., & Lee, H. (2008). *Formation of Au Nano-patterns on Various* 

*Electrodes*, Solid State Ionics, Vol. 165, pp. 315-321, ISSN 0167-2738

of Physical Chemistry B, Vol. 104, pp. 11449-11459, ISSN 1520-6106

Journal of Electrostatics, Vol. 55, pp. 247-259, ISSN 0304-3886

Display, Vol. 14, Iss. 2, pp. 175-180, ISSN 1071-0922

Vol. 254, pp. 5607-5611, ISSN 0169-4332

*Accuracy Correction of Critical Dimension Errors Taking Sequence of Large-Scale Integrated Circuits Fabrication Processes into Account*, Journal of Micronanolithography MEMS and MOEMS, Vol. 7, Iss. 4, (October-December 2008), pp.

*Resolution, Dry Printing of Conducting Polymers for Organic Electronics*, Applied

*Science and Technology*, Vol. 47, No. 4, (July-August 2003), pp. 296-303, ISSN 1062-

(2003). *Coloured Electrochromic "Paper-quality" Displays Based on Modified Mesoporous* 

*Electrochromic Windows Based on Redox-chromophore Modified Nanostructured*, Journal

*High-Quality Images on Electrophoretic Displays*, Journal of Society for Information

*Substrates Using Simplified Nano-Transfer Printing Method*, Applied Surface Science,

New Energy and Industrial Technology Development Organization (NEDO) of Japan

Research project (ID: 99-2218-E-007-018-MY2),

Japan Society for the Promotion of Science (JSPS)

International Training Program (ITP),

043008, ISSN 1932-5150

7813-1, Burlington, USA

87048-8, Chichester, England

36812-X, New York, USA

20156-4, New York, USA

Funding decision 40104/07.

**8. References** 

3701

Industrial Technology Research Grant Program (ID: 06D48522d),

Finnish Funding Agency for Technology and Innovations (TEKES)


**16** 

*USA* 

**Thermal Microactuators** 

*Sandia National Laboratories* 

Leslie M. Phinney, Michael S. Baker and Justin R. Serrano

This chapter discusses the design, fabrication, characterization, modeling, and reliability of thermal microactuators. Microelectromechanical systems (MEMS) devices contain both electrical and mechanical components and are in use and under development for applications in the consumer products, automotive, environmental sensing, defense, and health care industries. Thermal microactuators are standard components in microsystems and can be powered electrically through Joule heating or optically with a laser. Examples of MEMS designs containing thermal microactuators include optical switches (Cochran et al., 2004; Sassen et al., 2008) and nanopositioners (Bergna et al., 2005). Advantages of thermal microactuators include higher force generation, lower operating voltages, and less susceptibility to adhesion failures compared to electrostatic actuators. Thermal microactuators do require more power and their switching speeds are limited by cooling

Extensive work has been performed designing, fabricating, testing, and modeling thermal microactuators. Howell et al. (2007) has reviewed the fundamentals of thermal microactuator design. Designs of electrically powered MEMS thermal actuators include actuators fabricated from a single material (Comtois et al., 1998; Park et al., 2001; Que et al., 2001) and bimorphs (Ataka et al., 1993). Thermal actuator designs using a single material are both symmetric, referred to as bent-beam or V-shaped, structures (Baker et al., 2004; Park et al., 2001; Phinney et al., 2009) and asymmetric (Comtois et al., 1998), which have a hot arm and a cold arm. Asymmetric actuators are also referred to as flexure actuators. Some studies investigated both bent-beam and flexure actuators (Hickey et al., 2003; Oliver et al., 2003). In addition to electrical heating, powering thermal microactuators optically using laser irradiation has been demonstrated (Oliver et al., 2003; Phinney & Serrano, 2007; Serrano & Phinney, 2008). Modeling efforts have focused on bent-beam microactuators (Baker et al., 2004; Enikov et al., 2005; Howell et al., 2007; Lott et al., 2002; Wong and Phinney, 2007) and

This chapter focuses on bent-beam and flexure microactuators. In order for thermal actuators to operate, sufficient heating and thermal expansion of the components must occur. However, device temperatures that are too high result in permanent deformation, damage, and degradation in performance. In addition, packaging processes and conditions affect the performance and reliability of microsystems devices motivating studies on the

effects of surrounding gas pressure and mechanical stress on thermal MEMS.

flexure actuators (Mankame and Ananthasuresh, 2001).

**1. Introduction** 

times.


Acreo, http://www.acreo.se

Corning, http://www.corning.com

E Ink, http://www.eink.com


Pixtronix, http://www.pixtronix.com

Qualcomm, http://www.qualcomm.com

Sipix, http://www.sipix.com

Silicon Light Machine, http://www.siliconlight.com

Texas Instruments, http://www.ti.com
