A “plasmonic cover” could theoretically render objects “nearly invisible to an observer,” say University of Pennsylvania engineers.

A plasmonic screen suppresses scattering by resonating in tune with the illuminating light. Plasmons are waves of electron density, caused when the electrons on the surface of a metallic material move in rhythm. The researchers say that a shell of plasmonic material will scatter light negligibly if the light’s frequency is close to the resonant frequency of the plasmons. The scattering from the shell effectively cancels out the scattering from the object.

However, shielding from visible light would be possible only for microscopic objects.