Programming Complex and Arbitrary Shape Changes in Liquid Crystal Elasotmers

Liquid crystal elastomers (LCEs) are reversible shape responsive materials that are promising for many applications including biomedical devices, microfluidic pumps and soft robotics. To date, programming complex shape changes in LCEs requires locally aligning the liquid crystals throughout the material to form a predetermined director profile. Here we demonstrate a straight-forward method that does not rely on foresight of the liquid crystal director to program complex reversible shape changes. Using an optimized two-step synthesis method we mechanically deform the LCEs into arbitrary shapes between the first and second cure steps. The resulting competitive double-network LCE is capable of transitioning between its initial shape and its programmed shape when heated and cooled, respectively. We demonstrate the versatility of this method in a variety of shape changes including films capable of transforming into a flower and a face.