Frances Arnold

Frances H. Arnold is the Linus Pauling Professor of Chemical Engineering, Bioengineering, and Biochemistry in the Division of Chemistry and Chemical Engineering at the California Institute of Technology. She earned a B.S. in mechanical and aerospace engineering from Princeton University in 1979 and a Ph.D. in chemical engineering from the University of California, Berkeley in 1985. Arnold joined Caltech as a visiting associate in 1986 and advanced through the ranks as assistant professor of chemical engineering from 1987 to 1992, associate professor from 1992 to 1996, professor from 1996 to 1999, and professor of chemical engineering and biochemistry from 1999 to 2000. She held the Dick and Barbara Dickinson Professorship from 2000 to 2017 before becoming the Linus Pauling Professor in 2017. Since 2013, she has directed the Donna and Benjamin M. Rosen Bioengineering Center. Her laboratory teaches courses such as ChE/BE 163: Introduction to Biomolecular Engineering.

Arnold pioneered directed evolution methods for enzymes, earning the 2018 Nobel Prize in Chemistry for this breakthrough in protein engineering. Her research integrates directed evolution, computational simulation, and machine learning to design novel enzymes for biocatalysis in pharmaceutical synthesis, biofuels, sensors, and diagnostics, as well as to study natural enzyme evolution. Key publications include "Directed evolution of enzymatic silicon-carbon bond cleavage in siloxanes" (Science, 2024), "Biocatalytic Synthesis of α-Amino Esters via Nitrene C–H Insertion" (J. Am. Chem. Soc., 2024), "A Biocatalytic Platform for the Synthesis of Organofunctional Silanes and Siloxanes" (Angew. Chem. Int. Ed., 2025), and seminal works like "Directed Evolution: Bringing New Chemistry to Life" (Angew. Chem.). Among her honors are the 2025 Priestley Medal, the American Chemical Society's highest award; the 2016 Millennium Technology Prize; the 2011 National Medal of Technology and Innovation; the 2019 Bower Award for Achievement in Science; and the 2017 Sackler Prize in Convergence Research. Arnold's innovations have transformed synthetic biology and sustainable chemistry.