Magicians have long created the illusion of levitating objects in the air. Now researchers 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.
Researchers from Harvard University and the National Institutes of Health (NIH) have measured, for the first time, a repulsive quantum mechanical force that could be harnessed and tailored for a wide range of new nanotechnology applications.
The study, led by Federico Capasso, Robert L. Wallace Professor of Applied Physics at Harvard’s School of Engineering and Applied Science (SEAS), will be published as the January 8 cover story of Nature.
The discovery builds on previous work related to what is called the Casimir force. While long considered only of theoretical interest, physicists discovered that this attractive force, caused by quantum fluctuations of the energy associated with Heisenberg’s uncertainty principle, becomes significant when the space between two metallic surfaces, such as two mirrors facing one another, measures less than about 100 nanometers.