Professor Tomiki Ikeda, along with his research team at the Tokyo Institute of Technology have developed a plastic motor that runs on direct light. Unlike solar power, there is no need for storing energy before conversion. The motor can achieve this feat thanks to a plastic compound containing azobenzene which contracts when exposed to ultraviolet light and returns to its original shape when exposed to visible light. By making this material into a belt and wrapping it around two wheels of different sizes, movement can be generated when the larger wheel is exposed to ultraviolet light and the smaller one to visible light.
According to Ikeda, the material is not very efficient at converting light into energy, but he is confident that it will improve in time. He also noted that the material is about 4 times more elastic than human muscle, and it maintained its strength during a test despite contracting and expanding every 7 seconds for 30 hours. He hopes that one day the technology will come of age to the point that we will all be driving around in light-powered plastic automobiles. Maybe—if by "we" he means our grandchildren and great grandchildren. [Pink Tentacle via DVICE]