Chiral material reverses Casimir force, say physicists

The Casimir force can be tuned and even reversed by placing a chiral optical material between two similar surfaces – according to calculations by  Qing-Dong Jiang and Frank Wilczek at the University of Stockholm. The duo’s finding gets around a famous “no-go” theorem, which says that the Casimir force between two similar surfaces must always be attractive. The research could be of practical use because the Casimir force can inhibit the operation of nanomechanical devices.