Floating colloid carpets

Colloids coated with long DNA strands spontaneously form a crystalline two-dimensional carpet that hangs several micrometers above a surface, say UK scientists. 

Erika Eiser and Nienke Geerts, at the University of Cambridge, were attempting to build a 3D photonic crystal, and were extremely surprised to discover the colloids floating above the surface. This had not been seen before, and only been suggested in theory, she explains. More...

http://www.rsc.org/Publishing/ChemScience/Volume/2010/01/floating_colloid.asp