Super silver screen
A team at MIT have published details on how to make a transparent screen. This is an exciting development as it can be used to turn ordinary glass panels into projection screens.
The solution uses a thin polymer and silver coating so in fact almost any transparent material can be used for projecting images.
Current projection technologies rely on awkward prisms (such as Google Glass) or expensive integrated electronics (smartphone and tablet screens), or have restricted angles of vision.
The screen developed by the scientists at MIT uses a relatively simple and cheap method. Tiny particles of silver, measuring just 64 nm across, were mixed with polyvinyl alcohol. When that solution dries, it leaves behind a transparent, thin polymer behind. The silver nanoparticles scatter a certain wavelength of light – in this case, 458 nm frequency, or bright blue light.
Testing the polymer screen with a laser projector showed its capability in projecting light. This means that, in principle at least, such coatings could be applied to windows, windscreens, and so on.
The team now aims to further develop the coating so that it also scatters other visible light. Assuming coatings could be made that scatter red and yellow too, we could in theory soon be seeing full-colour displays that are almost entirely see-through when they’re not in use.
Besides being translucent, core advantages include a wide viewing angle, low cost and ease of manufacture. All this adds up to a very important development indeed, and the phrase ‘silver screen’ has never been so apt!