Bend me, shape me, any way you want me

A new range of photoresponsive polymers can adopt different three-dimensional shapes when exposed to light through a pair of patterned photo masks, according to Ryan Hayward and colleagues at the University of Massachusetts, Amherst, US. In much the same way that a flat leaf can curl to form 3D shapes, so the layered polymers can be made to form caps, almost spherical structures and more complex surfaces by appropriate patterning and exposure to light. The process happens reversibly and might be useful in mimicking the behavior and structure of human tissues for artificial muscles and self-actuated systems or even in tissue engineering acting as dynamic scaffolds on which new organs might be grown.