INNOVATORS - Navy's research on biological nanotechnology - Brief Article

All Hands, March, 2001

Honey, I Shrunk the Nurse

The Navy is looking at the use of tiny devices to do what a human nurse would normally do, only from within he human body.

Similar to "Star Trek: Voyager's" Borg Nano-probes, (but more benign) these virus-sized devices are made from biomolecules and tiny nickel propellers. So far, the Navy has been able to successfully assemble these devices inside test tubes. Eventually, the Navy wants to use them in ultra-miniaturized sensors and power sources.

Funded by the Office of Naval Research in Arlington, Va., this biotechnological achievement may well usher in a generation of microscopic robotic medical devices that would be assembled within living cells. These could then move about the human body, minister to its needs, or detect chemical signals from body cells and calculate and precisely dispense drugs and other treatments.

Powered by the enzyme ATP (adenosine triphosphate), the so-called "energy of life," these hybrid nanodevices can be assembled, maintained and repaired using the physiology of life itself.

"With this demonstration, we believe we are defining a whole new technology," said Carlo Montemagno, lead scientist for this program being conducted at Cornell University, Ithaca, New York.

However, researchers caution that before the nanodevices can actually carry out their intended role as "nanonurses" inside living organisms, a higher operational success rate needs to be achieved.

Nanobiotechnology is a relatively new field of science that merges living systems with fabricated nonliving materials, such as silicon, at the "nano" scale, where a nanometer equals one billionth of a meter. Eventually, researchers would like to engineer biomolecular motors powered by photons -- light energy -- instead of ATP. They also plan to add computational and sensing capabilities to the nanodevices, which ideally would be able to self-assemble inside human cells.

Like something out of a "Captain Marvel" story, the diminutive propellers were fabricated using electron gun evaporation, isotropic etching and electron beam lithography. Thin coatings of attachment chemicals encouraged the propellers to self-assemble. In initial tests, some of the biomolecular motors spun their propellers for more than two hours, at eight revolutions per second.

"This is all new for us ... and for everyone else in this line of work," said Montemagno, who noted that only five of the first 400 motors worked. "These machines are as small as virus particles -- it's hard to keep them from clumping together."