It’s a creation expected to reduce the cost of heating and cooling for homes and businesses. It took five years for University at Buffalo Professor Sarbajit Banerjee and his students to invent a window film that repels heat from the sun.
“Smart Window” coating is a clear laminate that is easily applied to windows. Banerjee says the coating is made of a chameleon type material that lets in sunlight, but prevents too much heat from getting in.
“What happens is a phase transition and it goes from one form of matter to another in response to heat. So the closest analogy is that when you apply heat to ice it melts the water, but here it doesn’t actually melt to become a liquid. But this material changes structure very slightly and by switching from one phase to the other it either lets in heat or it blocks heat,” explains Banerjee.