Dr. Stephen K. Streiffer became the director of Oak Ridge National Laboratory (ORNL) on October 16, 2023. As the twelfth director in ORNL’s history, Streiffer leads more than 6,500 staff in delivering on critical national missions by leveraging the laboratory’s world-leading facilities, tools, and signature strengths in neutron science, high-performance computing, advanced materials, biology and environmental science, energy technologies, nuclear science and engineering, isotopes, and national security research.

Streiffer came to ORNL from SLAC National Accelerator Laboratory, where he served as interim director. He joined SLAC in June 2022 as Stanford University’s vice president responsible for oversight of the lab. He previously spent 24 years in research and leadership positions at Argonne National Laboratory, concluding his tenure as the lab’s deputy director for science and technology.

His time at Argonne included leading the Photon Sciences Directorate and serving as director of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science user facility that generates ultra-bright, high-energy X-ray beams for researchers from government, academia, and the private sector. While overseeing APS, Streiffer helped to lead the APS Upgrade, an $815-million project to improve photon performance by two to three orders of magnitude.

During the COVID-19 pandemic, from March 2020 through May 2022, Streiffer served as co-director of DOE’s National Virtual Biotechnology Laboratory (NVBL), a consortium that leveraged the national labs to address challenges related to testing, treatment, epidemiological modeling, and supply chain bottlenecks encountered during the height of the pandemic. Earlier in his tenure at Argonne, he helped to create and lead Argonne’s Physical Sciences and Engineering Directorate—which includes its Materials Science, Chemical Sciences and Engineering, Nanoscience and Technology, High Energy Physics, and Physics divisions. Streiffer also served as deputy associate laboratory director for its predecessor Energy Sciences and Engineering Directorate. From 2000–2009, he served a leadership role in development of Argonne’s Center for Nanoscale Materials, another Office of Science user facility.

Streiffer’s scientific expertise is in nanostructured complex oxides and the structural characterization of materials using transmission electron microscopy and X-ray scattering techniques. He has authored or co-authored more than 180 scientific publications and holds one patent. Streiffer earned his doctoral degree in materials science and engineering from Stanford University and his bachelor’s degree in materials science from Rice University. He is a fellow of the American Physical Society and a member of the Materials Research Society and Institute of Electrical and Electronics Engineers.