Adaptive Materials and Systems Inspired by Cephalopod Skin
Cephalopods (e.g., squid, octopuses, and cuttlefishes) are a class of marine invertebrates known for their marvelous color-changing and camouflage capabilities. Such stunning visual feats are physically enabled by cephalopods’ sophisticated skin architectures that consist of various types of optically active organs and cells, including pigmentary chromatophores, reflective iridophores, and diffusive leucophores. Because of the unmatched optical functionalities, these soft-bodied animals (and their bio-optical skin components) have recently emerged as numerous inspiration sources for a variety of bio-derived and bio-inspired technologies. Within this context, we concentrate on adaptive optical and protonic materials and systems inspired by cephalopod skin. First, we study the long-range proton conduction in a designer cephalopod protein and explore the possible correlations between the protein’s self-assembled structures and electrical functions. Next, we draw inspiration from cephalopod skin and develop a stretchable multimodal camouflage platform from a high-performance synthetic proton conductor. Then, we develop and validate a new class of squid-inspired adaptive infrared-reflecting materials and systems that allow on-demand modulation of infrared radiation. Subsequently, we develop blue-ringed octopus-inspired multifunctional camouflage and signaling platforms from an exceptionally stable nonacene with adaptive visible and near-infrared optical and fluorescent functionalities. Last, we draw inspiration from cephalopods’ size-variable chromatophores and engineer a series of large-area camouflage applications with an unprecedented combination of characteristics. Overall, our findings may open opportunities for stealth technologies, bioinspired photonics, flexible optoelectronics, bioelectronics, energy conservation, and soft robotics.