The American Chemical Society Presents Its Highest Honor to Frances Arnold

The American Chemical Society has presented Frances Arnold, the Linus Pauling Professor of Chemical Engineering, Bioengineering, and Biochemistry at the California Institute of Technology, with the 2025 Priestley Medal, the organization’s highest honor.

Dr. Arnold was recognized “for her pioneering contributions to the development of directed evolution as a method for chemical and biological design.” She first developed the bioengineering method in the 1990s. Today, directed evolution is used by laboratories across the globe to make effective and sustainable chemical and biological products.

Throughout her career, Dr. Arnold has received numerous other prestigious awards. In 2018, she won the Nobel Prize in Chemistry. In 2011, she became the first woman to win the Charles Stark Draper Prize from the National Academy of Engineering. She received the Millennium Technology Prize in 2016 and was awarded the National Medal of Technology and Innovation in 2013. Additionally, she was the first woman to be elected to all three branches of the National Academies: the National Academy of Engineering (2000), the National Academy of Medicine (2004), and the National Academy of Sciences (2008).

Dr. Arnold first joined the Caltech faculty in 1986, ultimately earning the rank of full professor in 1999. In addition to her teaching duties, she currently serves as director of the Donna and Benjamin M. Rose Bioengineering Center.

Dr. Arnold holds a bachelor’s degree in mechanical and aerospace engineering from Princeton University in New Jersey and a Ph.D. in chemical engineering from the University of California, Berkeley.