January 8, 2009
Scientists Coax Tiny Objects into “˜Levitating’
Scientists say they have discovered the mechanism that causes tiny objects to levitate, a discovery that may pave the way for the ability to create nanotechnology machines in the future.
The apparent levitation was observed as a result of repulsive force between a thin sheet of silica and a small gold-plated bead, Harvard physicist Federico Capasso and colleagues reported in the journal Nature.
This so-called Casimir force of repulsion could be replicated and used to create friction-free parts for nanotechnology machines, researchers said.
"This is an experiment we are sure will work," Capasso said.
Dutch physicist Hendrik Casimir first described the effect that causes attraction and repulsion to occur between two tiny objects held close together in a vacuum.
"By reducing the friction that hinders motion and contributes to wear and tear, the new technique provides a theoretical means for improving machinery at the microscopic and even molecular level," Dr. Duane Alexander of the NIH's National Institute of Child Health and Human Development said.
"The emerging technology of nanomechanics has the potential to improve medicine and other fields," he said in a statement.
Through harnessing the quantum force, tiny machines could be developed to assist in surgery, manufacturing food and fuel and boosting computer speed.
Capasso previously conducted related work while working as the vice president of physical research at Bell Labs.
"I started to think how can I use these exotic quantum mechanical forces for technology," he told Reuters.
In very small objects, this force can cause moving parts to stick together, an effect known as stiction.
A Russian team had predicted this force could be reversed using the right combination of materials.
"The next experiment we want to do is use a TV camera to track the motion of one of these spheres, then we should be able to see easily whether you have levitation," Capasso told New Scientist.
Capasso's team has already filed for patents.
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