Dr. Samuel Graham

Dr. Graham is the Eugene C. Gwaltney, Jr. School Chair and Professor in the Woodruff School of Mechanical Engineering. He holds a courtesy appointment with the School of Materials Science and Engineering and a joint appointment with the Energy and Transportation Science Division at Oak Ridge National Laboratory. Prior to joining Georgia Tech, he was a Senior Member of the Technical Staff at Sandia National Laboratories in Livermore, California.  He is a Fellow of American Society of Mechanical Engineers and a member of the Air Force Scientific Advisory Board.


Jingjing Shi

Jingjing received her B.E. in School of Aerospace Engineering from Tsinghua University, China in 2012. She received her Ph.D. in Mechanical Engineering from Purdue University in Fall 2018. Her doctoral research was focused on the atomic scale simulations of thermal transport across interfaces. Currently she is working on the modeling of heat transfer in materials like wide bandgap semiconductors.

Chao Yuan

Chao joined the group in May of 2019, is working on wide bandgap semiconductor materials and interface thermal characterization using optical techniques, including time-domain thermoreflectance (TDTR) and transient thermoreflectance (TTR).  His past work at University of Bristol as a Post-Doctoral Fellow was focused on developments of GaN-on-Diamond microwave technology for high-efficiency microwave systems, and transducer-less TTR technique for non-invasively characterising GaN-based materials. He received his Ph.D. and B.E. in School of Power and Engineering from Huazhong University of Science and technology (China) in 2017 and 2012, respectively. His doctoral research involves developing highly thermal conductively thermal interface materials.

Riley Hanus

Riley joined the group in November of 2019 and is working on characterization of wide-band gap semiconductor devices. During his Ph.D. work at Northwestern University he was awarded the Weertman Fellowship from the NU Materials Science Department and the Graduate Student Award from the International Thermoelectric Society for his work on heat conduction in defective crystals. At the end of his Ph.D., he spent 5 months at Oak Ridge National Lab as a Science Graduate Research Awardee conducting neutron scattering experiments and developing new computational methods to simulate defective and complex crystals. Prior to his Ph.D. he received a B.S. from Iowa State University in Materials Engineering, and worked as Product Development Engineer at Bemis Company Inc. developing plastic food packaging.

Additionally, Riley is a co-founder and advisor for CalcHub, a company developing a simple yet powerful online math workspace.

See more about Riley here.

Graduate Students

Nicholas Hines

Nick received a B.S. in Applied Physics from Morehouse College and a B.S. in Mechanical Engineering in May 2015 through the Atlanta University Center Dual Degree Engineering Program (AUC DDEP). He joined the group in the fall of 2015 receiving a President’s Fellowship and a GEM PhD Fellowship supported by Corning Incorporated. Nick is currently working to complete his M.S. in Mechanical Engineering Thesis in pursuit of the Ph.D. in Mechanical Engineering. His current research interests are dedicated toward the realization of advanced thermal management solutions for GaN-based electronic devices by leveraging optical and electrical techniques including Raman and Photoluminescence Spectroscopy, Electrical Resistance Thermometry, and Transient Thermoreflectance techniques for thermal and thermomechanical characterization of wide bandgap (WBG) semiconductor materials.

Gabe Cahn

Gabe received his B.S. in Mechanical Engineering from the University of Maryland, College Park.  After several years in the defense industry designing packaging and next-gen cooling systems for high power electronic systems, picking up a Masters from Johns Hopkins along the way,  he decided to return to academia for a PhD. His research is in mechanics of thin films for flexible electronic applications.

Jason Hirschey
Jason Hirschey graduated with his BS in mechanical engineering with a thermal, fluids, and energy concentration from Georgia Tech in 2016.  His current research is thermal energy storage with phase change materials in collaboration with Oak Ridge National Lab.  Outside of work, Jason enjoys backpacking and camping, cooking, walking his dog, and woodworking.

Samuel Kim

Sam received his B.S in Mechanical Engineering from Yonsei University and M.S. in Mechanical Engineering from Georgia Tech in 2011 and 2014, respectively. Prior to joining the Graham Lab in the fall of 2017, he worked at Korea Industrial Institute of Technology (KITECH) in Micro/Nano Scale Manufacturing R&D Group. He is interested in micro/nano scale heat transport phenomena and is currently working on the investigation of thermal properties of wide bandgap power electronics with photothermal and electrical characterization techniques.

Brian J Kelly

Brian received his B.S. (2015) and M.S. (2018) in Mechanical Engineering at Washington State University Vancouver (WSUV). Brian’s M.S. thesis  research focused on the development of novel heat sinks for electronics thermal management. At the Advanced Energy Systems lab at WSUV, Brian assisted in the development of nanofluid use in pulsating heat pipes (undergrad), as well as, a novel radial pulsating heat pipe (master’s thesis project). Brian started at EMRL in Summer 2018 and is currently investigating the feasibility of phase change material (PCM) utilization for peak temperature throttling of GaN HEMTs. In addition to Brian’s research interests, he is a passionate educator and regularly tutors and mentors aspiring science and engineering students. Brian is also an avid strength athlete and an active member at the Citadel Nutrition Barbell Club (which was founded by the Georgia Tech Barbell Club). LinkedIn

Chidinma Imediegwu

Chidinma received her B.S in Mechanical Engineering with a minor in Business Administration in 2013 and her Masters in Mechanical Engineering and Material Science in 2015 from Southern University Baton Rouge, Louisiana. Her NASA funded thesis project centered on the Automated Healing of Elastomer Particle Infused Polymer Composites. She is currently pursuing a PhD at Georgia Tech with a research focus on Transient Liquid Phase Bonding employed for durable and thermally efficient electronic packages.

Robert Montgomery

Rob received his B.S in Mechanical Engineering from Georgia Tech in Spring of 2018 with a Micro- and Nano- Engineering Concentration. He joined EMRL is Fall of 2018, initially working on the thermal management and characterization of Gallium Nitride power electronics. He has since pivoted to primarily focus on the development, simulation, and characterization of memristors for use in neuromorphic computing. An active member of his community, Rob volunteers as a youth leader at Saint Anne’s Episcopal Church, helping to supervise and guide young people. Outside of work, Rob enjoys marksmanship, bourbon collecting, programming, debate, and flying. Rob is co-advised by Dr. Satish Kumar.

Jinho Hah

Jinho Hah completed his B.S. in Materials Science and Engineering at Georgia Institute of Technology in 2017, graduating in three years with highest honors. He then continued his studies to obtain a Masters in 2019 and is currently a Ph.D. candidate in the same department. His current research involves developing barrier adhesive and filler materials for encapsulation of flexible and transparent organic perovskite solar cells and device fabrication and characterization for use in neuromorphic engineering. Outside of his studies, Jinho has been an executive officer for the Georgia Tech Korean Student Association (GTKSA) for three consecutive years and is currently serving as the president of the organization. Jinho is co-advised by Prof. C. P. Wong.

Shangkun Wang

Shangkun Wang graduated from Huazhong University of Science and Technology (HUST) in 2019 with a Bachelor degree with honors in Energy and Power Engineering. His undergraduate research focus on microfluidics and combustion. Now he is pursuing his Ph.D. in Mechanical Engineering at The Graham Lab. Shangkun’s current research interests lie in thermal transport in wide bandgap semiconductor materials and through interfaces by using various experimental methods. Besides research, Shangkun loves debate, sports, music and playing the accordion.

George Woodruff School of Mechanical Engineering