Wouldn't it be awesome to be able to morph your body and change your skin colors at will, the way encephalopods and zebrafish can? There are so many potential benefits... and now we may have the next best thing.

Inspired by these shape-shifters, researchers at the University of Bristol have developed two different techniques that they believe could be used to create "smart clothing" and "smart materials" that can pull-off similar camouflaging tricks.

In a recent example the researchers demonstrated "artificial muscles" that could twitch and transform at the flick of a switch [see video above]. The malleable muscles were inspired by chromatophores, a specialist cell found in amphibians, fish, reptiles and cephalopods. It's these same cells that enable some animals to change both their shapes and colors. Organisms like the zebrafish can change their physical appearance depending on their mood, temperature, stress, or on account of something present in their environment. It's thought that these skills are used for camouflage, communication, and attracting a mate.


To create the artificial chromatophores, the Bristol researchers were inspired by two animals in particular: the squid and the zebrafish.

Squids have a colour-changing cell that has a central sac containing granules of pigment. When the squid contracts its muscles, the central sacs expand, creating an optical effect that makes the squid look like it's changing color. Taking note of this, the researchers mimicked the fast expansion of these muscles by using dielectric elastomers (DEs), a smart material that they connected to an electric circuit. When a voltage is supplied, the materials contract, and when the voltage is stopped, they revert to their original shape.

The zebrafish, on the other hand, has a small reservoir of black pigmented fluid that it can spread around its skin at various intensities. This effect was replicated by the researchers by using two glass microscope slides sandwiching a silicone layer. Two pumps were positioned on both sides of the slide and were connected to the central system with tubes, one pumping opaque white liquid, the other a mixture of black ink and water.

According to the development team, their artificial chromatophores may eventually be made into artificial compliant skin which can stretch and deform, yet still operative effectively.

The study was published on May 2 in IOP Publishing's journal Bioinspiration and Biomimetics.