Plastic shape shifter for smart stents

Temperature-controlled 'triple-shaped plastics' that can change shape from one form to another, then yet another, have been developed by researchers in Germany and the US.¹ Such materials might find use as switches and actuators in microelectromechanical systems (MEMS) and in medicine as intelligent stents for opening up blocked blood vessels. 

Scientists at the GKSS Research Centre of Biomaterial Development in Teltow, near Berlin, and the Massachusetts Institute of Technology (MIT) in Cambridge, US, created these new materials by blending two distinct polymers composed of long, chain-like molecules and adding bonds at varying points between them. These cross-links control the permanent shape of the new material at the molecular level. Like in a rubber band, the polymer network can be deformed but then snaps back to its original shape once you let go. A rubber band is composed of a single-shape polymer.