Researchers Levitate Object At A Microscopic Scale
Magicians have long created the illusion of levitating objects in the air. Now researchers at the National Institutes of Health and Harvard University have actually levitated an object, suspending it without the need for external support.
Working at the molecular level, the researchers relied on the tendency of certain combinations of molecules to repel each other at close contact, effectively suspending one surface above another by a microscopic distance.
The new technique may prove useful to the emerging field of nanomechanics — the development of microscopic machinery. Named for the nanometer — one billionth of a meter — nanomachinery would operate on the molecular level. By altering and combining molecules, tiny machines and even robots could be devised to perform surgery, manufacture food and fuel, and boost computing speed.
"The emerging technology of nanomechanics has the potential to improve medicine and other fields," said Duane Alexander, M.D., director of the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "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."
The study appears in the Jan.8 issue of Nature.
The research was conducted by Jeremy N. Munday and Federico Capasso of Harvard University, and V. Adrian Parsegian, Ph.D., head of the Section on Molecular Biophysics at the NICHD.
Dr. Parsegian explained that, analogous to the way like poles of magnets repel each other, certain combinations of molecules generate repulsive electrical forces that will prevent them from coming in contact with each other under certain conditions.
In their study, the researchers brought a tiny gold-plated sphere in contact with a flat glass surface, separating them with a liquid known as bromobenzene. At close distances, the molecular forces of the two surfaces, when in the presence of bromobenzene, repelled each other, so that the molecules of gold and glass never came in direct contact with each other and were separated by a few nanometers.