LIBE - The film can be made using a two-step process that's "very simple and very scalable," according to grad student Eugene Cho. The scientists start with materials called azobenzenes that change their chemistry when exposed to sunlight. They then modify them so that they can change states with a burst of heat, which in turn releases much more energy. The current prototype can increase the ambient temperature by 10 degrees Celsius (about 18 degrees Fahrenheit), which is enough to break ice off of a windshield, for instance. Since the material is transparent, it could be used on the front windshields of cars, saving a lot of energy over the normal defrosting process.