Light-Controlled Polymers

Finland's Tampere University of Technology (TUT) is developing light-controlled materials that change their shape, length or thickness in response to light. The new method enables researchers to employ UV light to program the shape the material adapts, and then elicit the different types of movements by shining red light on the material.

"Our concept for developing this material is actually quite simple. It is based on a combination of two well-known light-induced control mechanisms. No one has ever tried this before, despite, or maybe because of, the simplicity of the underlying idea. Our results are a good example of how novel results can be achieved by combining something known in a new way," says Academy Research Fellow Arri Priimägi who heads the Smart Photonic Materials group at TUT.

Nature paper "Reconfigurable photoactuator through synergistic use of photochemical and photothermal effects" by Markus Lahikainen, Hao Zeng, and Arri Priimagi describes the work of the researchers.

A Youtube video shows the light sensitive polymer in action:



The team has designed "an optical flytrap that was inspired by the way the Venus flytrap ensnares its prey. The optical flytrap is a small elastomer strip – less than one centimetre in length – that is glued onto an optical fibre into which blue light is coupled. When an object in the flytrap's field of view reflects light onto the elastomer surface, the strip bends itself around the object, capturing it like a Venus flytrap. The optical flytrap is able to lift hundreds of times its own weight."