Researchers print structural colour with an inkjet printer

Sounds very interesting. Just started looking at the paper, which seems very complex to me "An alternative approach utilizes light absorption via localized surface plasmon resonances (LSPRs) of noble metal nanoparticles (NPs)".

I came across https://www.nano-resonance.com/ which appears to be the promotional page for the technique, it has a nice diagram which appears to show how the size of the silicon nanoparticle enhances certain wavelengths of light.

Very cool how they can use an inkjet printer for their approach.

Also see https://en.wikipedia.org/wiki/Lippmann_plate for a photographic process that creates colours using diffraction patterns.

https://www.youtube.com/watch?v=-DyrBDsKA5s is a fun video on lippmann plates.

I don't understand these statements:

"...smart displays and vibrant art pieces (that won’t fade over time)... However, when the display is turned off, the images become visible, which allows for information display without using any energy."

Nowhere does it say that the coloration can be changed, once applied. The different-sized particles are embedded in acrylic. So how does this enable a "smart display?" I guess you can say that a turned-off monitor can now show "information," but that information printed on the screen would be static for all time... wouldn't it?

> Images printed with structural colour ink can be made both highly transparent to transmitted light (top) and at the same time reflect light from above in vivid colours (bottom)

Probably a foolish question, but wouldn't there be some unavoidable loss of brightness to the transmitted light, unless the structured color somehow "knows" to transmit light in one direction and reflect it in the other direction (which seems impossible given that it is printed by an inkjet)?