Unlike existing colour-changing materials, this new photochromic colloidal swarm relies on rearranging existing pigments rather than generating new chromophores in situ. The research result is recently published on Nature.
In nature, the skin of cephalopods (animals with tentacles attached to the head) exhibits unparalleled camouflage ability. Their skin contains pigment groups that can sense changes in environmental light conditions and adjust their appearance through the action of pigment cells. Although intricate in nature, this colour-changing ability is fundamentally based on a mechanical mechanism in which pigment particles are folded or unfolded under the control of radial muscles.
Inspired by this natural process, we develops a novel wavelength-selective intelligent colloid system to achieve light-controlled multi-dimensional phase segregation. The team forms dynamic photochromic nanoclusters by mixing cyan, magenta and yellow microbeads, achieving photochromism on a macro scale. This macroscopic photochromism relies on light-induced vertical phase stratification in the active microbeads mixture, enriching coloured microbeads corresponding to the incident spectrum.