Recently, scientists have developed a type of "intelligent glass" that can transform from opaque state to transparent state and adjust according to different wavelengths.
The "intelligent glass" is a research achievement that was made by scientists of Lawrence Berkeley National Laboratory and Autonomous University of Barcelona. Made of the mixture of niobate and nano-scale indium tin oxide (ITO), the so called "intelligent glass" is of the glass's characteristics: all molecules are in disordered arrangement that does not take on definite model like the liquid. However, ordinary window glass is made of the mixture of silicon dioxide and other materials like sodium oxide, magnesium oxide, and calcium oxide etc.
Research fellows add ITO after dissolving the niobate into the water. After that, they heat the mixture to volatilize the solution. As a result, the mixture will turn into a kind of amorphous solid. Subsequently, research fellows put the niobate glass on the top of the electrode, and then add a layer of electrolyte and the second electrode on the glass. When the research fellows adjust high the voltage at the electrode, the glass's transparency will alter. When the voltage hits 4V, the glass will become utterly transparent. If the voltage is 2.3V, the glass can resist near infrared ray. At the voltage of 1.5V, the glass can resist visible rays and near infrared ray. Intelligent glass's trait of resisting given wavelength should be attributed to changes of the nano crystal's structure by the electric charge.
As for practical application, this kind of intelligent glass can be mounted onto the normal glass's surface in the form of layer, thus it serves as a fixture of the building. However, it is not utility or safe to large-sized windows; even so, doors or windows do not set a limit to those materials that change according to demands. Moreover, additional production process is not a must.