Researchers in the US are a step closer to commercialising smart windows that can selectively let in light and heat.

The researchers in 2013 developed a smart glass that could switch between blocking light, heat or both using a small jolt of electricity. Now they have further refined the development with a new “cool mode” and “warm mode”.

The researchers said the cool mode material was a major step towards commercialisation because it enabled the blocking of 90 per cent of near-infrared light and 80 per cent of the visible light from the sun, and took only minutes to switch between modes, whereas in 2013 it required hours.

The development of the “nanostructured architecture for electrochromic materials” could reduce energy costs associated with cooling buildings and homes in summer.

“This material could be ideal for application as a smart electrochromic window for buildings,” Cockrell School of Engineering chemical engineering professor Delia Milliron said.