While in China last week, I participated in a ribbon cutting ceremony for a new private (rather than public) funded hospital. Each patient room included several high tech amenities including showers that transition from clear glass to frosted glass at the touch of the button.
How is that accomplished? Simple - smart glass that employs polymer dispersed liquid crystal devices.
A liquid mix of polymer and liquid crystals is placed between two sheets of glass. When no voltage is applied, the crystals are randomly aligned and the panel is translucent. When voltage is applied, the crystals are aligned and light passes without scattering, making it appear clear.
No curtains and no blinds are needed.
If power fails, privacy is protected.
Glass that changes from cloudy to clear at the touch of button. That's cool!