Hiding from the enemy

Camouflage is widely used by folks in the military to conceal personnel and vehicles, enabling them to blend in with their background environment or making them resemble anything other than what they really are.

In modern warfare, however, a growing number of sensors can 'see' in parts of the spectrum where people cannot. Therefore, designing camouflage for a wide variety of terrains, and enabling it to be effective across the visual, ultraviolet, infrared and radar bands of the electromagnetic spectrum is crucial.

One way to do this is to examine how the natural camouflage of animals enables them to hide from predators by blending in with their environment, and then mimicking those very same techniques using man-made materials.

Thinking along such lines, a team of researchers from Harvard University (Cambridge, MA, USA)  announced this month that they have developed a rather interesting system that allows robots inspired by creatures like starfish and squid to camouflage themselves against a background.

To create the camouflage, the researchers create fine micro-channels in sheets of silicone using 3-D printers which they then use to dress the robots. Once they are covered with the sheets, the researchers can pump colored liquids into the channels, causing the robots to mimic the colors and patterns of their environment.

 The system's camouflage capabilities aren't limited to visible colors, however. By pumping heated or cooled liquids into the channels, the robots can also be thermally camouflaged. What's more, by pumping fluorescent liquids through the micro-channels, the silicone sheets wrapped around the robots can also be made to glow in the dark.

According to Stephen Morin, a postdoctoral fellow in the Department of Chemistry and Chemical Biology at Harvard University, there is an enormous amount of spectral control that can be exerted with the system. In the future, he envisages designing color layers with multiple channels which can be activated independently

Dr. Morin believes that the camouflage system that the Harvard researchers have developed will provide a test bed that will help researchers to answer some fundamental questions about how living organisms most efficiently disguise themselves.

For my money, however, it might be more lucrative to see if the camouflage could be deployed to help the military hide its personnel in the field more effectively.

Reference: Camouflage and Display for Soft Machines, Science magazine, 17 August 2012:  Vol. 337 no. 6096 pp. 828-83.