The same researchers that introduced the partial invisibility cloak are back in the news with the prospect of levitation. On his webpage, Ulf Leonhardt describes his goal, "It is possible to turn the Casimir force from attraction to repulsion and to use it for levitating mirrors on, literally, nothing. The Casimir Force is a very subtle property whereupon two objects exert an attractive force upon one another due to vacuum fluctuations and energy carried in fields. Using a special lens, Leonhardt's team is able to reverse the Casimir Force in such a way as to create basic levitation. The technology can be used to create frictionless components and is hoped to improve performance of nanotechnology machines that suffer from "sticking."