Giving liquid crystals the brush-off
Paul Hamelinck and Wilhelm Huck from the University of Cambridge, UK, made a patterned surface where polymers could grow on only part of the pattern. By controlling the radical polymerisation they grew polymers with lots of branched side chains, like a brush.
These brushes arrange themselves into a dense, organised array so that they can only grow upwards. The array forms a layer with a thickness that can be carefully controlled to as little as five nanometres.
When liquid crystal molecules are added to the modified surface, the high level of organisation in the brushes forces the liquid crystal molecules to align with each other. This controlled alignment will be useful for developing tuneable optoelectronic devices in the future.