J. Fraser Stoddart, a Nobel Prize-winner and UCLA professor emeritus in chemistry, died on Dec. 31, 2024. He was 82. 

The Scottish-born scientist taught at UCLA from 1997 to 2008, gaining worldwide recognition for his research in creating machines at the molecular level. In 2016, the Nobel committee recognized Stoddart for his development of a “rotaxane,” a structure in which a molecular ring is threaded onto a thin molecular axle, and for demonstrating that the ring could move along the axle. This achievement led to innovations such as a molecular lift, a molecular muscle and a molecule-based computer chip.

Stoddart’s research team at UCLA led the world in making molecular switches, designing and manufacturing these interlocked molecules in which the relative motions of the components can be switched in controlled ways.

Stoddart and his colleagues successfully demonstrated a large-scale ultradense memory device that stores information using the reconfigurable molecular switches. These intricate, mechanically interlocked molecules assembled in Stoddart’s UCLA laboratory were an important step toward the creation of molecular computers that are much smaller and potentially more powerful than today’s models. 

The team also designed and constructed a molecular motor of nanometer size, powered only by sunlight. At the time, Stoddart listed a number of possible applications for the development, including nanoelectronics, molecular computers and nanovalves that could be used for the delivery of anticancer drugs and other medications.

In 2008, Stoddart was appointed Board of Trustees Professor of Chemistry at Northwestern University, where he established the Stoddart Mechanostereochemistry Group and became director of the Center for the Chemistry of Integrated Systems. He was also appointed Chair Professor of Chemistry at the University of Hong Kong in 2023.

Every year, Stoddart would return to UCLA to award the Norma Stoddart Prize for Academic Excellence and Outstanding Citizenship, named in memory of his late wife, to a UCLA doctoral graduate in the chemistry and biochemistry department. 

He was knighted by Queen Elizabeth II in 2007.

Stoddart is survived by two daughters.