Researchers from the University of California, Berkeley created a light-responsive hydrogel made from graphene and elastin-like proteins. When light (a laser) is shining on the gel, it curls inward rapidly. This property is called phototropism - plants use it to orient towards a light source. This material may be useful in robots, drug delivery and synthetic tissue engineering.
The idea behind the new material is that the graphene sheet generates heat when exposed to infrared light,. This causes the proteins to release the water the cling to when not heated.