I've just started at https://www.phantomconnections.space/phpBB3/viewtopic.php?f=3&t=751672 simplyvids The researchers embedded some of those nanoscale heat sponges into glass made from niobium oxide, which darkens when exposed to current. Together, the two materials allow control of both heat and visible light passing through the window. The composite remains essentially transparent to both forms of radiation until a voltage is applied, at which point the crystals switch on to soak up heat. Boost that voltage, and the crystals continue to block heat as the niobium oxide darkens, screening out light.