Team designs lens able to turn Casimir-Polder force repulsive

Jun 5, 2008 09:48 GMT  ·  By

By harnessing a force that generally makes matter stick together, a team of researchers from the University of St. Andrews that had previously demonstrated that invisibility cloaks could one day be feasible, showed that they can levitate objects by reversing the effects of the Casimir force. The same phenomenon is said to be able to levitate a whole person in the near future.

The Casimir effect is a physical consequence of quantum mechanics and is manifested through the Casimir-Polder force acting on objects separated by distances as small as a few micrometers. It can either be expressed through a force of attraction or repulsion depending on the configuration of the objects. It is neither of electromagnetic nor of gravitational nature, but rather due to fluctuations of energy in the space-time fabric, and is one of the forces that make atoms bundle together.

With the help of a special lens, professor Ulf Leonhardt and Dr Thomas Philbin from the St Andrews university claim to have been able to engineer a Casimir force that only repels objects. In nanotechnology, the Casimir force can cause quite a lot of trouble while trying to build electrical circuits or tiny mechanical devices, but the findings of the St Andrews research team may solve some of them by making objects repel instead of attracting each other.

"The Casimir force is the ultimate cause of friction in the nano-world, in particular in some microelectromechanical systems. Such systems already play an important role - for example tiny mechanical devices which trigger a car airbag to inflate or those which power tiny 'lab on chip' devices used for drugs testing or chemical analysis. Micro or nano machines could run smoother and with less or no friction at all if one can manipulate the force", said professor Leonhardt.

The technology to levitate objects as big as a human being is already available; however, this is the first time when the Casimir effect is mentioned for such an application. Although, the Casimir-Polder force acts on very small distances, usually between objects under a micrometer apart, the newly designed lens may be able to considerably extend that distance, said Dr Philbin.

The St Andrews team is just one of the three in UK that reported having achieved invisibility in certain light wavelengths by bending electromagnetic waves around an object.