South Korean scientists have developed a new type of “smart” window that turns dark when the sun comes out and becomes transparent when it gets cold, so that you can save on heating bills by soaking in free heat from the sun.
The new material may help save more energy while also keeping houses cool in summer, and warm in winter, scientists say.
Similar windows already exist, but the researchers say their method allows for an almost instantaneous switch from opaque to transparent.
“This type of light control system may provide a new option for saving on heating, cooling and lighting costs through managing the light transmitted into the interior of a house,” the BBC quoted them as saying.
“Smart windows can prevent the inside of a building from becoming overheated by reflecting away a large fraction of the incident sunlight in summer.
“Alternatively, they can help keep a room warm by absorbing the sun”s heat in winter,” they said.
Previous ”smart windows” tended to be costly, and deteriorate rapidly – as well as using various toxic products in their production.
Which is why Ho Sun Lim from Korea Electronics Technology Institute, Jeong Ho Cho and Jooyong Kim from Soongsil University set out to develop a smart window that overcomes these drawbacks.
They discovered that using a polymer, a layer of ions, and a solvent such as methanol was an inexpensive and less harsh way to make a stable, robust smart window.
It has the added advantage of being extremely tunable by quickly and easily switching from 100 percent opaque to almost completely clear in seconds, researchers say.
The study has been published in the journal ACS Nano.