Micro Motor

Breakthrough Seen in Chemist Kelly's Discovery

By Mark Sullivan
Staff Writer

Vanderslice Professor of Chemistry T. Ross Kelly and colleagues at Boston College have created a 78-atom molecular paddle wheel that is one of the world's smallest motors.

The microscopic motor, described in the Sept. 9 edition of the scientific journal Nature , took four years to create. The prototype is considered a major breakthrough for scientists seeking to understand the workings of the biological motors, from the muscles to the lungs, that power the human body.

Online coverage of the breakthrough is available at ABC News at [http://www.abcnews.go.com/sections/science/DailyNews/nanomotors990908.html] and at BBC News at [http://news.bbc.co.uk/hi/english/sci/tech/newsid_441000/441670.stm]. A summary of the Nature article may be read online at [http://www.nature.com].

"This is even slower than the Wright Brothers, but it's proof of the principle that you can make a molecule move in one direction," Kelly said of the tiny, three-bladed rotor engine powered by bio-fuel that has been made to turn 120 degrees. The goal of continuous rotation remains distant, but is achievable, Kelly said.

The ramifications for biochemical research promise to be significant.

"Biological systems are full of motors," said Kelly, "from the little 'trains' that run inside cells and move nutrients back and forth, to the hair-like cilia in the lungs that push out dust particles, to the muscles that make our bodies move. But nobody understands how these biological motors work. Our research may help biochemists do so and may lead to treatments for people whose motors don't work right."

T. Ross Kelly with a model of the motor.

Asst. Prof. Scott Miller (Chemistry) agreed that Kelly's invention has potential. "If you could come up with a way to control motion, you could load up drugs in a carrier cell and point it where it needs to go, such as an organ with a tumor," he said.

"You don't know where the technology will go," Miller added, "But this discovery has the fundamental appeal of providing insight into how motion is regulated. And if you can regulate motion, it could be the key to orchestrating all sorts of things on the molecular level."

Just how small is a motor the size of a molecule? "If you start with something the size of a mosquito," explained Kelly, "and reduce its three dimensions by a factor of 10,000, until it's really tiny, that gets you down to the size of a cell. Take that and reduce its three dimensions by another factor of 10,000, and that gets you down to the size of a molecule."

Co-authors on the Nature article are two former post-doctoral assistants in Kelly's lab, Harshani De Silva and Richard Silva. The research is supported by a four-year grant of $850,000 from the National Institutes of Health.

Kelly said he has loved motors since he was a boy in Davis, Calif., building rockets and go-karts. His office in the Merkert Chemistry Center is filled with perpetual-motion machines, mechanical banks, tippy birds and wind-up gizmos.

"A common theme is motion," he said. "I bought some of them hoping they would give me ideas."

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