MIT researchers take a cue from color-changing beetles in quest to 3D print robot skin

When Subramanian Sundaram’s team hit a roadblock in its quest to build a 3D-printed robot, it turned, as roboticists often do, to nature. The team of MIT researchers drew inspiration for the latest step in the process from the golden tortoise beetle — a North America beetle species with a unique form of camouflage.

When threatened, the beetle’s shiny gold coloring drains from its shell, transforming into a translucent reddish-brown. The self-preserving trait served as an inspiration for the MIT scientists as they worked to build a 3D-printed flexible membrane that might one day serve as the basis for robotic skin, bringing various sensors to the exterior of the machine.

Sundaram speaks humbly when discussing the biomimicry (biological inspiration), drawing one small piece of inspiration from nature as part of a long, ongoing process. “It’s easy to look at nature because we are so far behind,” he tells TechCrunch, referring to the seemingly impossible tasks of truly replicating a biological species.

“It’s like looking at the moon and trying to get to a tree top,” he adds. “Even though we look toward the beetle for inspiration, we are very, very far away from being able to make something like that. Its capabilities are insanely cool. We can look and try to take bits and pieces from nature, but implementing all the functionality is really hard.”

In this case, the team borrowed from the simple defensive trait as a proof of concept, building the optic-changing property into a flexible printed substrate. “We wanted to do this sensing-processing actuation,” says Sundaram. “Doing the actuation is one of the biggest problems in 3D printing. Optical actual is somewhat easier.”

The printing process distributes a half-dozen materials through a MultiFab 3D printer, while a copper-and-ceramic heater is employed to help insert semiconducting plastics into the mix. Through the print process, the team has managed to replicate the natural function of the insect in a single, solid 3D-printed circuit board.

The team believes the technology could prove an important step toward created a fully 3D-printed robot packed with sensors. It could also go a ways toward informing the research of a fellow MIT team working to create 3D-printed robots that change shape when heated.