Recent research has found a way to reverse the Casimir force, which causes objects to stick together at nanoscales. This enables nanoscale levitation — among other things it could dramatically reduce friction in nanodevices. It could also enable new kinds of nanodevices in which for example rotating parts are levitated and held in place using the reverse Casimir force rather than by nanoscale axles or housings. For example nanowheels on a nanobot could perhaps be held in place and could turn without an axle. This could simplify the geometry of nanodevices, reducing the cost of manufacturing of more complex devices while also reducing the number of parts that could break. In addition, reversing the Casimir force could eliminate the main cause of friction (called "stiction") in nandevices — it causes parts to stick together such that they can’t even move. The solution to this problem has traditionally been to test and discard a percentage of defective nanodevices after production. Eliminating stiction by reversing the Casimir force could perhaps reduce these costs and make the process of nanomanufacturing more efficient.
St Andrews scientists have discovered a new way of levitating tiny
objects – paving the way for future applications in nanotechnology.
Theoretical physicists at the University of St Andrews have created
`incredible levitation effects’ by engineering the force of nature
which normally causes objects to stick together by quantum force. By
reversing this phenomenon, known as `Casimir force’, the scientists
hope to solve the problem of tiny objects sticking together in existing
Professor Ulf Leonhardt and Dr Thomas Philbin of the University’s
School of Physics & Astronomy believe that they can engineer the
Casimir force of quantum physics to cause an object to repel rather
than attract another in a vacuum.
Casimir force (discovered in 1948 and first measured in 1997) can be
demonstrated in a gecko’s ability to stick to a surface with just one
toe. However, it can cause practical problems in nanotechnology, and
ways of preventing tiny objects from sticking to each other is the
source of much interest.