The Electric switchable glass, also known as smart glass or privacy glass, is a high-tech glazing material that can alter its light transmission properties at the flick of a switch. This dynamic functionality allows it to change from transparent to translucent or opaque, effectively providing instant, on-demand privacy or shading without the need for blinds or curtains. The most common technology for this is Polymer Dispersed Liquid Crystal (PDLC). In its normal "off" state, tiny liquid crystal droplets within a polymer layer are randomly oriented, scattering light and making the glass appear frosted. When an electrical current is applied, the crystals align, allowing light to pass through directly and rendering the glass clear. This transformation happens almost instantaneously, offering seamless control over visibility and light levels.

The applications for this innovative material are vast and growing across multiple sectors. In commercial architecture, it is used for conference room walls, office partitions, and hotel bathroom windows, enabling spaces to be reconfigured for privacy or openness as needed. In the residential market, it is incorporated into bathroom enclosures, skylights, and interior doors to maximize open space feelings while retaining privacy on demand. Beyond privacy, it is also used in retail displays and projection screens, where its opaque state provides a perfect surface for images. While its initial cost is higher than traditional glazing and it requires a continuous power supply to maintain transparency, the benefits of space optimization, modern aesthetics, and enhanced user control make electric switchable glass a transformative technology in intelligent building design.