Dichroic 3D-printing material changes color with point of view

“In use since at least the 4th century AD, dichroic glass displays different colors depending on how it’s being viewed. Now, Dutch scientists have produced the effect in a material that can be used to create 3D-printed objects – and it’s not just a novelty, as it could have practical applications.

A team of researchers at Wageningen University started with regular polyvinyl alcohol (PVA), which is a widely-available polymer commonly used as a 3D printing medium. To this they added gold nanoparticles of varying sizes – not much of the gold was needed, as it ended up constituting only 0.07 percent of the resulting composite material’s weight.”

More information here.