M.S.E. Thesis Defense

Applied Modulated Thermoreflectance Microscopy for
the Detection of Buried Structures

Mr. Timothy James Smiley
 Advisor: Professor Jennifer Lukes
Department of Mechanical Engineering
University of Pennsylvania

Abstract
In opaque materials, buried features including cracks, holes, composite lamina and MEMS structures cannot be detected or evaluated using an optical microscope. There is a need for new nondestructive methods to characterize these features. In this study a scanning modulated thermoreflectance microscopy technique capable of such characterization has been developed and applied to the detection of buried microstructures. This method enables the analysis of buried cracks and defects in many materials and is also able to give detailed analysis of the layers in various composite structures. This laser-based technique was tested on samples of known structure that were microfabricated for the purpose of examining the range of applicability of the microscope and its resolution under various circumstances.  Comparison of experimental and FEMLAB computer modeling results shows that this technique is capable of accurately detecting buried structures of aluminum in PDMS with an estimated lateral resolution of 50 microns and a depth resolution of 2 microns.

Friday, September 8th – 10:00 AM
229-C Towne Bldg.