The primary functions of windows are to let light and warmth into the room, in addition to providing a view. We may not want all three of them at the same time. Swiss researchers had the same idea and are developing a simple method to smarten up windows by adding mini-mirrors in them to make sure that the rooms are comfortable throughout the year.
There have been a number of smart windows in the recent years but they all have the same problem. Not only are they complex, they need some kind of power source. The researchers from Switzerland are developing a simpler solution to make smart windows. These windows remain transparent but can selectively allow light into the room while making sure the heat stays out.
The team used a precision laser to create a grooved microstructure on the surface of a film. Compound Parabolic Concentrator (CPC) lenses are actually tiny mirrors and they were evaporated into the pores on the surface. This array of mini-mirrors has the ability to reflect sunlight into the room with a greater efficiency and light up every corner of the room.
The researchers claimed that the smart windows were able to reflect 80 percent of the incoming light at an incidence angle of 60 degrees in their tests and it was spread out almost horizontally in the room. The team also assured that the glass does not turn murky and remains completely transparent.
These smart windows are also seasonal. They can reflect the light and heat away in the summer and into the room in winter. This is controlled by the angles of the mirrors. In summers, they are arranged in such a way that the light bounces back when it hits them and the lower position of the sun in winters allow them to reflect more light and warmth inside the room.
This will definitely cut down the heating and cooling costs in both the seasons. The team is currently working on installing prototypes in an Empa building and monitoring its performance. They are also working on mass producing their product. Sounds pretty promising, doesn’t it?