The team said that some of the limitations of current transparent technologies include the inability to see projected images from more than one specific angle as well as the complexity and expense of glass equipped with built-in electronics.
The technology that they’ve developed is relatively simple: they embed nanoparticles (silver, 60nm) into a plastic polymer sheet. The nanoparticles are tuned to allow all light to pass through except for one wavelength, and when a projector aims an image (moving or stationary) at the plastic sheet, just one color will be reflected back to the viewer’s eye.
With this method, you get an almost completely transparent display without much complexity. Further, the team believes that the plastic materials will be cheap and freely available--as in, you could drop by the office supply store and grab some.
This display technology could be used for heads-up displays (HUD) almost anywhere, from spectacles to windshields, as well as for store window displays, office windows, and advertising on subway train windows.
In the future, the display will be even more transparent and upcoming prototypes should be able to handle more colors in order to produce full-color images.