Programmable liquid crystal material responds to external stimuli

materials containing microscopic liquid crystals that move and stretch in any direction in response to their environment, such as solar panels whose microstructure follows the sun

Inspired by natural microstructures whose movement gives materials and expected properties, such as the highly flexible hair-like features which make gecko's feet sticky, researchers at the Wyss Institute for Biologically Inspired Engineering and the John A Paulson School of Engineering and Applied Sciences at Harvard investigated liquid-crystal elastomers (LCEs), materials whose molecular structure contains flexible, stretchy polymers with internal crystalline elements that dictate the directions in which the elastomeric sections can move and stretch. Until now, synthetic LCEs have mostly only been able to deform in one or two directions.

The team, directed by Joanna Aizenberg and Yuxing Yao, experimented with synthesising LCEs in a magnetic field which could be manipulated as the materials formed. The field influenced the orientation of the liquid crystal elements, and this orientation was maintained once the polymer had solidified. This orientation dictated how the material would deform when heated to a temperature that disrupted the structure of liquid-crystal elements. When cooled, however, the material would return to its original shape, which was dictated by casting the forming polymer.