World’s Smallest Motor Donated to Pasadena Museum of History

In 1959, Dr. Richard Feynman, the famous CalTech theoretical physicist, issued a challenge at a meeting of the American Physical Society that effectively ushered in the field of nanotechnology. “I want to offer a prize of $1,000 to the first guy who makes an operating electric motor – a rotating electric motor that can be controlled from the outside that will be (in size) only 1/64th of an inch cube, not counting the lead-in wires.” Much to Feynman’s surprise, a year later, a young Pasadena-based electrical engineer successfully fulfilled the challenge.

William McLellan (1924-2001), a CalTech graduate and miniaturization specialist, spent just two and one-half months laboring on the project, using tools such as toothpicks and a watchmaker’s lathe. Only six one-thousands of an inch in diameter (about the size of a speck of sand), the micromotor contains four coils (21 turns per coil) of wire two one-thousandths of an inch in diameter, a quartz bearing, a tiny rotor — 13 parts in all – and it has an output of one-millionth horsepower. It is mounted under a microscope so that one can see the individual parts. Although there is no effective use for the micromotor – McLellan suggested it 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.

Donation to Pasadena Museum of History

The original micromotor, a larger demonstration copy, and archival material including notes, photographs, and clippings were recently donated to the permanent collection of Pasadena Museum of History by the Estate of William McLellan. “The history of 20th century Pasadena was shaped in part by the outstanding, and often astonishing, scientific achievements of its residents,” notes PMH Executive Director Jeannette O’Malley. “The micromotor is one tangible example of such an achievement and is an important addition to our collections.” Copies of the micromotor are also in the collections of Cal Tech, the Smithsonian, and the London Science Museum.

McLellan Micromotor on Public View June 22

The tiny motor will be on display at Happy Birthday Pasadena: Celebrating Bridges, the free community event on Saturday, June 22, 1:00 to 5:00 pm commemorating Pasadena’s 127th birthday and the 100th anniversary of the Colorado Street Bridge. Appropriately, this celebration of the City’s rich history will explore not just our iconic architectural bridges, but also our bridges to Community, Exploration, Health, History, Imagination and Understanding.

The McLellan Micromotor and ancillary materials will be housed for safekeeping in the PMH permanent archives. Plans for further public display will be announced in the future.

For more information, visit www.pasadenahistory.org.