Squid and zebrafish inspired materials could help camouflage

London, May 3 (ANI): Researchers have come up artificial muscles that mimic the colour-changing ability of squid and zebrafish.

The technology developed by scientists at the University of Bristol falls into the category of soft robotics - a domain that blends together organic chemistry, soft materials science, and robotics.

The researchers decided to combine biomimicry - technology that imitates nature - and robotics.

"We study and mimic the characteristics of biological organisms to create soft robots and soft devices," the BBC quoted Dr Jonathan Rossiter as saying.

"Where conventional robots are rigid and inflexible, we focus instead on the soft structures that nature is so good at making. These include artificial muscles."

To design artificial muscles, the researchers studied how some animals changed colour.

They do it for a number of reasons - in case of danger, or depending their mood, stress level, changes in outside temperature, when communicating or attracting a mate.

Cephalopods - squid, cuttlefish and octopuses - change colour by using tiny muscles in their skins to stretch out tiny sacs of black colouration.

These sacs are situated in the animal's skin cells, and when a cell is ready to change colour, the brain sends a signal to the muscles and they contract.

This makes the sacs to expand and creates the optical effect that makes the animal look like it is changing colour.

The scientists also stated that zebrafish had a different camouflaging ability - by pumping black pigmented fluid from under the skin to the surface of the skin.

To mimic these natural processes, the team used "smart" electro-active polymeric materials, connected to an electric circuit.

When a voltage was applied, the materials contracted; they regained their original shape when they were short-circuited.

"These artificial muscles can replicate the [natural] muscular action... and can have strong visual effects," said Dr Rossiter.

"These materials, and this approach, is ideal for making smart colour-changing skins or soft devices in which fluid is pumped from one place to another.

"This could help us create a whole host of new technologies, ranging from active-camouflage and clothes that change colour and pattern, to a smart second-skin that can cool you when you are hot and keep you warm when you are cold," Dr Rossiter added.

The study appears in the journal Bioinspiration and Biomimetics. (ANI)