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Scientists look to sperm to power nanobotsFlagellum could potentially provide locomotion, early research suggestsby Bryn Nelson
Columnist
MSNBC contributor
updated 9:32 a.m. ET Jan. 2, 2008 A tiny assembly line that powers the whip-like tail of sperm could be harnessed to send future nanobots or other tiny medical devices zooming around the human body, according to a preliminary research report.
Borrowing a page from reproductive biology, the proof-of-principle study offers a peek at how nanotechnology might overcome the problem of supplying energy to the envisioned menagerie of nanobots, implants and “smart” probes aimed at releasing disease-fighting drugs, monitoring enzymes and performing other medical roles within a patient’s body.
To be biologically compatible, these hypothetical devices would need to be formed not from tiny springs and nuts and bolts but from biomedical components. “At that scale, biology provides the best functional motors,” said Alexander Travis, an assistant professor of reproductive biology at Cornell University’s Baker Institute for Animal Health. “But how do you power these kinds of structures?”
One potential answer has come from the tail, or flagellum, that propels human sperm at a rate of about 7 inches per hour. (In comparison, if a 6-foot man swam the equivalent number of body lengths in an hour, his tally of 3.7 miles would smash the American long-distance swimming record.)
To supply the energy for its locomotion, a sperm cell’s tail is essentially studded with tiny assembly lines that produce a high-energy compound called ATP. Officially known as adenosine triphosphate, ATP has been called the universal energy “currency” of living cells because of its ability to store, transfer and release energy. When a power source is needed to run processes within a cell — say, bending and flexing a sperm’s flagellum — ATP releases its reserves through a process that results in its decay to a simpler chemical form.
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