Samuel Graham
Samuel Graham Eugene C. Gwaltney, Jr. School Chair
MRDC Building, Room 3214

Dr. Graham is a Professor with the School of Mechanical Engineering and holds a courtesy appointment with the School of Materials Science and Engineering. Prior to joining Georgia Tech, he was a Senior Member of the Technical Staff at Sandia National Laboratories in Livermore, California.

Dr. Graham's research centers on exploring the properties of thin-films used to create MEMS and nanotechnology devices. Specifically, his research concentrates on the growth of thin films and developing methods to characterize their thermal transport properties and reliability. In this work, a variety of testing technologies are used to measure the thermal conductivity of materials with thicknesses of 100 nm or greater. Thermal transport properties are measured from cryogenic temperatures up to 1100K, which will allow the investigation of the properties of thin-films used in MEMS for harsh thermal environments. This work is important for understanding the role of microscale transport phenomena and the stability of transport properties in thermal MEMS devices and solid oxide fuel cells. His research efforts focus on polycrystalline Si and SiGe thin-films as well as ceramic and electrodeposited materials for MEMS devices and fuel cells. Additional work will explore the development of models to account for microscale heat transfer effects on the thermal conductivity of materials.

In other work, Dr. Graham is focusing on methods to measure temperature and thermal conductivity directly on MEMS structures. Using optical methods like photothermal reflectance and Raman spectroscopy, efforts are underway to provide a full-field temperature map of MEMS devices with higher spatial resolution than can be obtained by infrared technologies. In using modulated heating and probing sources, both local temperature and thermal conductivity can be mapped with a spatial resolution on the order of a few hundred nanometers or smaller. In future work, these modulated optical sources will be extended to allow the probing of the structures of materials which have gradients through their thickness. Such technologies will be applied to multilayer thin-films and CVD materials used in MEMS fabrication.

The type of research performed by Dr. Graham is very useful in the areas of manufacturing and designing reliable MEMS and nanostructured materials for a variety of structural and thermal applications. Typically, students who work for Dr. Graham find that interdisciplinary research combining mechanical engineering, materials science, and applied physics to be very appealing. The objective is to educate students in the area of fundamental property-processing relationships, and to determine ways to exploit this knowledge for the efficient design of devices.

Graduate Students
Selected publications: 
  1. J. Lee, et al., 2007. Thermal Conduction From Microcantilever Heaters in Partial Vacuum. Journal of Applied Physics101, 014906-1014906-6. Selected for republication in the Virtual Journal of Nanoscale Science & Technology 15(3), 2007.; T. Beechem, et al., 2007. The Role of Interface Disorder on Thermal Boundary Resistance Using A Virtual Crystal Approach. Applied Physics Letters, in-press.
  2. M. Abel, et al., 2007. Raman Thermometry of Polysilicon MEMS in the Presence of an Evolving Stress. Journal of Heat Transfer, in press.
  3. A. Allen, et al., 2006. Nanomaterial Transfer Using Hot Embossing For Flexible Electronic Devices. Applied Physics Letters88, 083112083114. Selected for republication in the Virtual Journal of Nanoscale Science & Technology 13(9), 2006.