Metamaterials could lead to frictionless micro and nanoscale machines.
Metamaterials (which exist) lead to perfect lens (research is progressing towards this goal). Perfect lens can be used to reverse the casimir force (computational result) and the perfect lens can be used to enable frictionless machines (if computations hold and engineering is successful).
The normally attractive Casimir force between two surfaces can be made repulsive if a "perfect" lens with a negative index of refraction is sandwiched between the surfaces, according to calculations done by physicists in the UK. Ulf Leonhardt and Thomas Philbin of the University of St Andrews reckon that the repulsive force may even be strong enough to levitate a tiny mirror. The repulsive effect -- which has yet to be observed experimentally -- could also help minimize the friction in micrometre-sized machines caused by the Casimir force (New Journal of Physics to be published).
The negative-index metamaterial is able to modify the zero-point oscillations in the gap between the surfaces, reversing the direction of the Casimir force. Indeed, the researchers believe that this repulsive force is strong enough to levitate an aluminium mirror that is 500nm thick, causing it to hover above a perfect lens placed over a conducting plate.
Since the Casimir force acts on the length scale of nanomachines, manipulating it could be important for future applications of nanotechnology. "In the nano-world, the Casimir force is the ultimate cause of friction," Leonhardt told physicsworld.com. "Our result means we could now envision frictionless machines or novel micromotors."