Scientists invent glass that can tu from clear to opaque in less than a second - CNET

Do drapes make you angry, and blinds fill you with moroseness? What you need is a window that offers clear views or privacy with the touch of a switch.

Tunable glass, that goes from transparent to opaque, has been developed before, notably with nanocrystals and metallic nanostructures. These are somewhat costly and difficult to manufacture, however.

Researchers professor David Clarke and postdoctoral fellow Samuel at Harvard John A. Paulson School of Engineering and Applied Sciences claim that their new method could be much cheaper to manufacture. They have described it in a paper published in the joual Optics Letters.

It consists of a sheet of glass sandwiched between two sheets of clear, soft elastomer. These have been sprayed with a coating of silver nanowires. This is what makes the manufacture so simple. Previous methods of creating tunable windows are manufactured using a technique called vacuum deposition, which painstakingly deposits molecular layers of material.

"Because this is a physical phenomenon rather than based on a chemical reaction, it is a simpler and potentially cheaper way to achieve commercial tunable windows," Clarke said in a statement.