World’s Smallest Motor: The McLellan Micromotor

McLellan with micromotor

William McLellan used a microscope to inspect his tiny motor, while holding a model one million times larger. 1960 (William McLellan Special Collection)

In 1959, Dr. Richard Feynman, the famous Caltech physicist, issued a challenge that effectively ushered in the field of nanotechnology. He offered a $1,000 prize to anyone who could make an operating electric motor which was only 1/64th of an inch cubed.  Much to Feynman’s surprise, a year later, a young Pasadena-based electrical engineer successfully fulfilled the challenge.

William McLellan (1924-2011), a Caltech graduate, spent just 2½ months laboring on the project, using tools such as toothpick and a watchmaker’s lathe.  About the size of a speck of sand, it is mounted under a microscope so that you can see the individual parts.  Although there is no effective use for the micromotor – McLellan suggested is could be “employed to run the merry-go-round for a flea circus”—the invention is considered a pioneer in the then-novel field of nanotechnology.

The original micromotor, a demonstration copy, and archival material including notes, photographs and clippings have been donated to the permanent collection of Pasadena Museum of History by the Estate of William McLellan. Other copies of the micromotor are also in the collections of Caltech, the Smithsonian, and the London Science Museum.

child with micromotor

(Scrapbook, McLellan Special Collection)

Child with micromotor

(Scrapbook, McLellan Special Collection)

– Laura Verlaque

History Keepers logoFrom August 4 through October 1, 2017, the McLellan micromotor will be displayed in the exhibition, History Keepers: Eleven Stories That Moved Los Angeles. Learn more about this exhibition.