Researchers from the University of Bristol have created artificial muscles that can be transformed at the flick of a switch to mimic the remarkable camouflaging abilities of organisms such as squid and zebrafish.
They demonstrate two individual transforming mechanisms that they believe could be used in 'smart clothing' to trigger camouflaging tricks similar to those seen in nature.
The study is published today, 2 May, in IOP Publishing's journal Bioinspiration and Biomimetics, and is accompanied by a video showing the camouflaging in action.
"We have taken inspiration from nature's designs and exploited the same methods to turn our artificial muscles into striking visual effects," said lead author of the study Jonathan Rossiter.
The soft, stretchy, artificial muscles are based on specialist cells called chromatophores that are found in amphibians, fish, reptiles and cephalopods, and contain pigments of colours that are responsible for the animals' remarkable colour-changing effects.
The colour changes in these organisms can be triggered by changes in mood, temperature, stress or something visible in the environment, and can be used for camouflage, communication or attracting a mate.
Two types of artificial chromatophores were created in the study: the first based on a mechanism adopted by a squid and the second based on a rather different mechanism adopted by zebrafish.
A typical colour-changing cell in a squid has a central sac containing granules of pigment. The sac is surrounded by a series of muscles and when the cell is ready to change colour, the brain sends a signal to the muscles and they contract. The contracting muscles make the central sacs expand, generating the optical effect which makes the squid look like it is changing colour.
The fast expansion of these muscles was mimicked using dielectric elastomers (D
|Contact: Michael Bishop|
Institute of Physics