The Scalable Thermal Energy Engineering Lab (STEEL) Gen3 CSP team performed thermophysical properties measurement on HTMs and CMs using advanced immersion electrothermal and photothermal techniques, and freely and openly disseminated the relevant thermophysical property datasets digitally to the public to support the Gen3 CSP demonstration project. Explore this page to find out more about the who of the STEEL Gen3 CSP team.

Our core team

Bettina K. Arkhurst

Graduate Student

Bettina Arkhurst joined STEEL in 2018 as a mechanical engineering Ph.D. student. Arkhurst is currently interested in low-cost alternative energy methods, though she has quite an eclectic research background. Her first undergraduate research experience was in Prof. Edward Boyden’s Synthetic Neurobiology lab at MIT, where she worked on a project focused on mouse virtual reality for in vivo neural recordings. Afterwards, she joined Prof. Rohit Karnik’s Microfluidics & Nanofluidics Research lab. Her research there centered around quality control techniques and instrumentation for use during the manufacturing of low-cost xylem water filters. She is passionate about how STEM can help students from lower socioeconomic backgrounds. She focuses on energy but is interested in everything science. Arkhurst’s project at STEEL revolved around the creation and utilization of a probe to measure the thermal properties of molten salts for concentrated solar power plants.

Sonja A. Brankovic

Graduate Student

Sonja Brankovic joined STEEL in 2018 as a mechanical engineering Ph.D. student. Brankovic’s research interests mainly fall within the macroscale thermodynamics field and include renewable energy systems and high-temperature materials. During her undergrad at the University of Illinois, she worked in an agricultural engineering lab that tested the effects of different thermal/chemical environments on egg production in controlled hen-houses. More recently, she worked in a pharmacology lab at the University of Pennsylvania where she tested the mechanical properties of arteries from a variety of mouse models and drug treatment protocols. At Tech, she focused on next-generation molten salt technology for concentrating solar power systems. In addition to her research, Brankovic launched a sustainability blog series, Buzz Bites, that’s published through the Georgia Tech Office of Campus Sustainability.

James F. Ponder Jr.

Postdoctoral Fellow

James, originally from south Florida, received his B.S. degree in chemistry from the University of North Florida in Jacksonville. During his time there he conducted research under Dr. Kenneth Laali in the field of ionic liquids. James joined the Reynolds group at Georgia Tech in the spring 2012 and graduated with his Ph.D. in the summer of 2017. He then joined the McCulloch group at Imperial College London to continue research on electroactive polymers. He joined the STEEL lab in the spring of 2020 to continue research on electroactive materials. James’ research is also focused on atom substitution and resulting heavy atom effects for both solid-state and redox applications. Outside the lab, he enjoys reading, weight lifting, hiking, and of course, coffee.

Michael Adams

Postdoctoral Fellow

Mike Adams joined STEEL as a postdoc in 2020 after completing his PhD in Mechanical Engineering at The Ohio State University, where he conducted research in the field of thermoelectrics. Under the advisement of Prof. Joseph P. Heremans, Adams published experimental demonstrations of active thermal switching and active cooling. He also conducted finite element modeling of a waste heat recovery generator with support from a Ford-OSU alliance program. After arriving at Georgia Tech, Adams expanded into new research topics including thermal transport in semiconducting polymers, thermal load shifting in buildings, and high-temperature materials for concentrated solar power systems.

Andrey Gunawan

Research Engineer II

Andrey Gunawan is a Research Faculty at STEEL, and is currently co-leading this Gen3 CSP project with Shannon Yee. He received his B.S. in Aeronautics & Astronautics from Institut Teknologi Bandung, M.S. in Aerospace Engineering from the University of Southern California, and Ph.D. in Mechanical Engineering from Arizona State University. Gunawan has over four years relevant experience working at high temperatures with challenging material constraints on the SunShot CSP: APOLLO project, developing a high-temperature (~850°C) sodium ion expansion heat engine. He is the recipient of several honors and awards including The Electrochemical Society (ECS) Joseph W. Richards Summer Fellowship (2014), Honorable Mention of the Link Foundation Energy Fellowship (2014), and together with his co-authors he received the Best Paper Award(s) in the ASME Power Division Student Paper Competition at the ASME Power & Energy 2015 and 2018 conferences.

Shannon K. Yee

Associate Professor

Shannon Yee is the PI of this Gen3 CSP project. Yee was also the PI on the SunShot CSP: APOLLO project, developing a high-temperature (~850°C) sodium ion expansion heat engine. He began at Georgia Tech in the fall of 2013 and was promoted to Associate Professor in 2019. Prior, in 2010, he was the first fellow to the Department of Energy’s Advanced Research Project Agency – Energy (ARPA-E) assisting to form the agency in its inaugural year. In 2008 he was awarded the prestigious Hertz Fellowship to support his research in energy. Furthermore, in 2007 he was a Department of Energy Advanced Fuel Cycle Initiative Fellow. Recently, he received the ONR Young Investigator Award, ASME Pi Tau Sigma Gold Medal, and AFOSR Young Investigator Award. Yee has also spent substantial time within the National Laboratory system, and has joint faculty and visiting scientist appointments with National Renewable Energy Laboratory (NREL) and Lawrence Livermore National Laboratory (LLNL), respectively.

Undergraduate student researchers

Adele Payman

Adele Payman is an Aerospace Engineering junior. She is working with Arkhurst to automate the electrothermal immersion technique inside the glovebox, minimizing human interaction with the probe and thus increasing the speed, efficacy, repeatability and reliability of the measurements. She has interned twice at the Jet Propulsion Laboratory in flight systems engineering, focusing on spacecraft propulsion systems and guidance, navigation and controls. Payman is a designer on the side. She has been designing graphics for Hyperloop Transportation Technologies, a sustainable transportation startup, since 2018.

Kristian Lockyear

Kristian Lockyear is a Chemical and Biomolecular Engineering senior, with a minor in Energy Systems. He is working with Brankovic to run high-temperature measurements of HTM and CM using both the LFA and the STA. He is doing his summer 2020 internships at National Renewable Energy Laboratory (NREL), focusing on work pertaining to renewable energy and/or environmental sustainability.

Scientific glassblower

S. Elayne Ashley

Elayne Ashley is a scientific glassblower, who has been helping us with the electrothermal immersion probe design and manufacturing. Although her Glassblowing Shop is based in the School of Chemistry and Biochemistry, she is available to any Georgia Tech unit to consult, design, modify, and fabricate scientific glassware. She designs and constructs glass apparatus in close collaboration with individual researchers. She received her Bachelor of Fine Arts in Glass and Ceramics at Jacksonville University and Scientific Glass Technologies at Salem College. Ashley is a recipient of the 2019 Rising Wreck Award, for her leadership qualities and initiative in solving problems and improving work situations.

Montgomery Machining Mall at the Woodruff School of Mechanical Engineering

Steven Sheffield

Steven Sheffield is the Machine Shop Supervisor, who has been helping us with machining our materials for measurements. Sheffield is responsible for managing the resources and personnel that assist School researchers and educators in fabricating equipment.

Scott Elliott

Scott Elliott is a Machine Shop Supervisor II. Elliott is responsible for managing the resources and personnel that assist School researchers and educators in fabricating equipment. He also has been helping us with machining our materials for measurements.

Nathan Mauldin

Nathan Mauldin is a Mechanical Specialist, who has also been helping us with machining our materials for measurements.

About the Solar Energy Technologies Office

The U.S. Department of Energy Solar Energy Technologies Office supports early-stage research and development to improve the affordability, reliability, and performance of solar technologies on the grid. Learn more at


This work was funded in part or whole by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Solar Energy Technologies Office Award Number DE-EE0008371.