Summary: this surface doesn't SWITCH between cooling and heating. It's a way to transform a material from transparent into either black or white (only once, non-reversible) with different lasers. Black will absorb sunlight (heating), white will radiate and reflect sunlight (cooling). Instead of two different dyes, you now only need one material.
Summary: this surface doesn't SWITCH between cooling and heating. It's a way to transform a material from transparent into either black or white (only once, non-reversible) with different lasers. Black will absorb sunlight (heating), white will radiate and reflect sunlight (cooling). Instead of two different dyes, you now only need one material.