Dr. Oluwaseyi BalogunNorthwestern University
The performance and functional reliability of engineering structures depend on the mechanical properties and defect state of their constituent materials. The ability to measure local mechanical properties, elastic strains, and identify defects in materials is crucial to assessing the mechanical integrity of civil, aerospace, and electronic structures. Ultrasound techniques are well established nondestructive methods for measurement of elastic properties, and detection and quantification of defects. These methods rely on measurement of, elastic wave propagation, scattering from elastic inhomogeneities, and elastic energy confinement, in a material. In this talk, I would review recent progress from my research group on the use of lasers for local excitation and detection of high frequency elastic waves, measurement of elastic properties of nanoscale structures, subsurface imaging of structural defects, and metrology of interface elastic properties. Furthermore, I would discuss our recent efforts to improve the spatial resolution of the ultrasound techniques through integration of scanning probe microscopy with conventional ultrasonic methods.
Oluwaseyi Balogun is an Associate Professor in the Departments of Mechanical Engineering and Civil and Environmental Engineering at Northwestern University. His research focuses on, multifunctional materials for controlling elastic/acoustic wave propagation, optical techniques for nondestructive evaluation, biosensing, and structural health monitoring, and phonon transport in materials. He obtained the B.Sc. degree in Mechanical Engineering from the University of Lagos, Nigeria, in 1998, and the M.S. and Ph.D. degrees in Mechanical Engineering from Boston University in 2003 and 2006. Before joining the faculty at Northwestern University, He spent 2006-2007 in the Materials Science and Engineering Department at The Johns Hopkins University, as a Postdoctoral Research Fellow, and the Lawrence Livermore National Laboratory as a Visiting Scientist. He was the Chair of the 2015 International Symposium on Laser Ultrasonics and Advanced Sensing.
Host: Dr. Didem Ozevin