The world's most minute propeller beanies have opened the door to nanoscale machines that one day may be able to scoot around human cells performing medical functions. Late last year, scientists at the Cornell University Nanobiotechnology Center created a cluster of nanoscopic machines that could spin their propellers at 480 revolutions per minute for nearly three hours.
Each one smaller than a virus, the little gizmos are composed of three parts. The cylindrical motor is a modified bacterium protein that converts ATP--the fuel used by and found in living cells--into mechanical energy to turn a drive shaft and propeller, both made of nickel. And in a neat trick, this bundle of organic and inorganic bits is self-assembling, thanks to strategically placed molecular coatings that attract one another.
The development is promising, but real medical applications remain a long way off, says the group's leader, Carlo D. Montemagno, an associate professor of biological engineering at Cornell. He dreams of a time when the addition of computational and sensing abilities will help create a class of self-assembling nanobots that can repair the human body. It should be possible to create "engineered prosthetic devices at the cellular level--machines that can run within living cells," he says.