Ocean STEMulation: From squid skin to smart clothing

Focusing on science, technology, engineering, and math (STEM), as they pertain to the ocean.

Have you ever watched an octopus change its skin to camouflage with its surroundings, or seen a squid use color to communicate?

This 6 minute video deals with bioluminescence and absolutely amazing camouflage capabilities of cephalopods.

The squid, octopus, and their relatives the cuttlefish and nautilus, all belong the class cephalopoda. Cephalopods are a group of mollusks, which means they are related to animals such as snails and mussels, but several traits set them apart. One of the most interesting characteristics unique to cephalopods is their ability to change the color and texture of their skin.

Researchers have studied how cephalopods do this, and they’re working on a manmade material that can do the same thing.

How do cephalopods change their skin color? The skin of cephalopods has chromatophores, special pigment-filled cells that come in a range of colors. The pigments can be black, brown, red, orange, or yellow. These cells are each independently controlled by nerves and muscles, which expand or contract the cell. When the muscles contract, the cell stretches, allowing the pigment to cover a larger area. When the chromatophore shrinks, the pigment is hidden.

They can have several other types of cells that also contribute to the unique qualities of the skin. In a layer underneath the chromatophores, cephalopod skin sometimes contains iridophores, which can’t be changed instantaneously like chromatophores can. They reflect light and look metallic and create green, blue, gold, and silver hues. There may also be a third layer with leucophores. Likie iridophores, leucophores reflect light, but they appear white or blue instead. Sometimes they also have photophores, which produce light through bioluminenscence.

Technology based on nature. By taking inspiration from cephalopods, scientists may have the first steps towards color-changing clothing for people. Researchers in the field of biomimicry, in which natural forms and systems are studied and imitated to solve human problems, created artificial muscles using dielectric elastomers, flexible manmade material that can expand and contract when connected to an electric circuit. When the scientists applied the current, fluid-filled sacs expanded enhancing the appearance of the color, just like a cephalopod’s chromatophores would. The researchers created another model based on zebrafish skin, which pumps colored fluid towards or away from the skin’s surface to change color.

The technology is still in its very early stages but perhaps one day soon biomimicry researchers will use this to bring us self-camouflaging clothing.