Artificial Cephalopod Skins with Switchable Appearance Color

Macromol Rapid Commun. 2025 Jan 21:e2400937. doi: 10.1002/marc.202400937. Online ahead of print.

Abstract

Cephalopods such as squids, octopuses, and cuttlefishes can change their bodies' color to match the surrounding environments by contracting or expanding the sac just below the surface of the skin. Inspired by this mechanism, artificial cephalopod chromatophores which are prepared by thermoresponsive poly(N-isopropyl acrylamide)-based hydrogel films embedded with black, red, and yellow pigments are presented, they can swell and shrink under temperature stimuli, like the natural chromatophores. The artificial chromatophores embedded with cuttlefish ink are further used to fabricate artificial J.heathi octopus skin by sandwiched between a transparent outer layer and a transparency-switchable substrate, thus camouflage skin can be achieved by controlling temperature or NIR irradiation. The artificial chromatophores with red and yellow pigments are further incorporated with the colloidal photonic crystals patches which are embedded in a white substrate, and the iridescence patches keep disappearing-reappearing with the expanding-contracting behavior of the pigment-containing chromatophores, like the skin of squids. These bioinspired artificial skins with the excellent capability of dynamic camouflage have potential applications for color displaying, camouflage, and smart wearable devices.

Keywords: artificial chromatophores; camouflage; cephalopods skin; structural color; thermoresponsive hydrogel.