This smart window uses electricity to quickly change from clear to dark

In a world where even mundane devices like

water bottles and toothbrushes have become smart and connected, it’s easy to scoff at yet another attempt at smartifying practical gadgets. But new technology for smart windows, described today in the journal Joule, might actually be an intelligent idea. That’s thanks to their energy-saving potential: Dynamic windows that darken when the sun is shining on them could help reduce cooling costs in the summer, just like putting down the blinds does. And with the help of an internet connection and an intelligent schedule, these could be automatic, so you wouldn’t have to remember when to turn them on and off.
Windows that tint on demand already exist—one prominent class of them is known as electrochromic windows. In fact, if you’ve flown on a Boeing 787 Dreamliner, you’ve seen electrochromic windows on the fuselage, which dim with a button’s press, either by the passenger or the flight crew. But a group of researchers at Stanford are aiming for a better, more dynamic one: Their prototype goes from transparent to opaque in less than three minutes. And it does it using an innovative approach.