New windows that are bio inspired from Moth’s eye are self cleaning, anti glare and save on energy costs. via ucl.ac.uk
The windows use nature inspired nanostructures which mimic the eyes of moths to cut glare, save energy and clean themselves. The prototype glass was developed with support from the Engineering and Physical Sciences Research Council (EPSRC) and tests confirm it delivers three key benefits:
· Self-cleaning: The window is ultra-resistant to water, so rain hitting the outside forms spherical droplets that roll easily over the surface – picking up dirt, dust and other contaminants and carrying them away. This is due to the pencil-like, conical design of nanostructures engraved onto the glass, trapping air and ensuring only a tiny amount of water comes into contact with the surface. This is different from normal glass, where raindrops cling to the surface, slide down more slowly and leave marks behind.
· Energy-saving: The glass is coated with a very thin (5-10 nanometre) film of vanadium dioxide which during cold periods stops thermal radiation escaping and so prevents heat loss; during hot periods it prevents infrared radiation from the sun entering the building. Vanadium dioxide is a cheap and abundant material, combining with the thinness of the coating to offer real cost and sustainability advantages over silver/gold-based and other coatings used by current energy-saving windows.
· Anti-glare: The design of the nanostructures also gives the windows the same anti-reflective properties found in the eyes of moths and other creatures that have evolved to hide from predators. It cuts the amount of light reflected internally in a room to less than 5% – compared with the 20-30% achieved by other prototype vanadium dioxide-coated energy-saving windows – with this reduction in ‘glare’ providing a big boost to occupant comfort.