September 28, 2011
“Smart” Window Detects Changing Seasons
South Korean scientists have developed a new "smart" window that switches from summer to winter mode.
The window darkens when the outside temperature is hot and becomes transparent when it gets cold in order to help capture heat from the Sun.
The researchers said their method allows for an instantaneous switch from opaque to a transparent window.
"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 scientists wrote in the journal ACS Nano.
"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."
Ho Sun Lim from Korea Electronics Technology Institute, Jeong Ho Cho and Jooyong Kim from Soongsil University used a special polymer made up of counter ions and solvents to create the window.
The scientists say the glass is cheaper than existing technology and much less toxic.
The window is able to switch from 100 percent opaque to almost completely clear in just a few seconds.
"Until now, the numerous technologies developed not only have been chemically unstable, prohibiting their use in long-term switching applications but have been accompanied by the use of expensive special equipment and complicated harsh processing conditions," the report said.
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