Smart glass is a general nickname for glass that is electrically switchable between tints or shades. There are several different types of smart glass technology, however the most prolific are suspended particle devices (SPDs). SPDs are sheets of glass that contain a matrix polymer film filled with crystalline particles encased in a carrier fluid. In their natural state these particles block light, with a non-uniform pattern preventing rays from passing properly.
Key to this tech is that when electricity is passed through the particles – via a pair of electrodes mounted to the polymer matrix – the current forces the particles to align in a uniform pattern. This allows a far greater quantity of natural light to penetrate the glass, granting it a transparent quality and high light value. Currently smart glass is being incorporated into offices, houses and vehicles – like the Mercedes-Benz 2012 SLK Roadster. Its popularity stems from the privacy it provides and also its heat-retention qualities, with shaded glass offering significant reductions in heat loss and thus overall energy savings.