DARPA's Maximum Mobility and Manipulation (M3) program is currently testing a small, rubber robot that is capable of changing colors to blend with its surroundings. The updated prototype, developed by Harvard University's Dr. George Whitesides and Dr. Stephen Morin, is equipped with a layer of capillaries that are used to circulate fluids or air throughout the unit. In the video below, the robot uses a dark-colored dye to blend in with its environment. DARPA says that fluids can be also be used to make the robot change its apparent shape and temperature, or glow in the dark.
In its current form, the robot is attached to an operator through a series of tubes that are used to pump the dye and air for movement. The advantage of using a silicone-based robot comes down to its durability and the low cost of manufacturing. DARPA has stated that a model like the one seen below can be made for less than $100, and is hopeful that the price can drop down to just a few dollars each in the future.