The Casimir effect is well known nowadays in physics: zero-point fluctuations in the electromagnetic field between two conducting plates give rise to an attractive force between them. Less well known, however, is that Michael Fisher and Pierre de Gennes predicted an analogue for condensed matter systems.
C Hertlein of the University of Stuttgart and colleagues have now observed this effect between two surfaces that were immersed in a binary liquid mixture close to criticality. Unlike the usual Casimir effect, this new one has a strong dependence on temperature, which could have applications in nanotechnology – where it is relatively easy to control this bulk parameter.