AVS 51st International Symposium
    MEMS and NEMS Monday Sessions
       Session MN-MoP

Paper MN-MoP13
Processing and Characterization of MEMS Thermal Switches for Emittance Control

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: S.L. Firebaugh, United States Naval Academy
Authors: S.L. Firebaugh, United States Naval Academy
M.A. Beasley, United States Naval Academy
R. Osiander, Johns Hopkins University
A.C. Keeney, Johns Hopkins University
R.L. Edwards, Johns Hopkins University
Correspondent: Click to Email
The trend towards smaller satellites requires a new type of thermal control. Current thermal control systems do not scale well with miniaturization. An alternative is to coat the satellite with an active "skin," formed by many microelectromechanical devices, that can control the emissivity of the satellite surface. Previous work has explored the use of microscale louvers and shutter arrays @footnote 1@. An alternative technique is to insert a variable thermal conductivity layer between the satellite and an emissive outer surface @footnote 2@. Our approach uses a MEMS switch to implement the variable thermal conductivity layer. This system relies on gold membranes, coated with an emissive upper layer and suspended above the device substrate on polymer posts. The application of a voltage pulls the devices into contact with the substrate, resulting in conduction of heat from the substrate to the outer layer, where the energy can be emitted as light. Prior work has described the initial prototype and test results for this design @footnote 3@, which verified the electrostatic model for the device. These prototype devices, however, were not optimized for thermal performance and did not include the high-emissivity layer which is crucial to device operation. This poster will discuss the implementation of the second generation design of the device, which includes design modifications and the development of a high-emissivity coating layer. @FootnoteText@ @footnote 1@ R. Osiander et al., "Microelectromechanical Devices for Satellite Thermal Control," to appear in IEEE Sensors J., August 2004. @footnote 2@ W. Biter et al. "Electrostatic Radiator for Spacecraft Temperature Control," Space Technology and Applications International Forum (STAIF 2004), pp. 96-102. @footnote 3@ M. A. Beasley et al., "MEMS Thermal Switch for Spacecraft Thermal Control," SPIE Photonics West Conference, San Jose, California, Jan 13-29, 2004.