Researchers at a Japanese company called RIKEN have discovered a way to turn light into kinetic energy through the use of molecules that change their structure when exposed to light. The molecules, when sandwiched and melted between sheets of Teflon literally coil when exposed to UV rays. It is the first time that researchers have been able to recreate a muscle-like movement in an artificial structure on a macroscopic scale.
The key element of the polymer film is Azobenzene — a molecule that consists of two benzene rings connected by two nitrogen atoms. Azobenzene (shown above) alters from a relatively straight formed molecule into a sort of a “V” when it comes in contact with direct energy from UV and visible light.
The polymer brushes that the RIKEN researchers used in their research consist of a polymethacrylate backbone with outstretched side chains in which Azobenzene molecules were inserted. The researchers then sandwiched these polymer brushes between thin sheets of Teflon and melted them together at 266 degrees Fahrenheit and then hot pressed them at 239 degrees Fahrenheit. During the process the team found that the polymer brushes oriented themselves horizontally along the Teflon sheets. The resulting 3D molecular ordering is what enables the entire sheet to bend in unison when exposed to light. The discovery could be a breakthrough in functional materials and could lead to light-powered muscle-like biomorphic devices.