This Tiny Robot Dons Shape-Shifting Exoskeletons to Perform Different Tasks

A tiny, cubic robot dubbed Primer has a closet full of shape-shifting exoskeletons that it wears to walk, roll, sail, glide, or shovel. Primer takes on a new ability with a simple change of outfit, suggesting a future where a single robot equips itself to perform multiple jobs instead of many robots each performing a specific task. This would be particularly advantageous in extreme or remote environments, such as in space or the deep sea.

Though Primer is only a 3.18 mm cube that weighs .24 grams, it demonstrated various feats of mobility and strength in several experiments. As a “wheel-bot,” it rolled 14.8 centimeters per second, 2.3 times faster than it can as a “walk-bot.” It floated across water as a “boat-bot,” transporting a load almost twice its own weight. And as a “glider-bot” it was able to glide a distance of 129 centimeters, 26 times its body length, from a height of 112 centimeters.

“It’s exciting to imagine robots as a kind-of Swiss Army knife that could be used for a range of tasks depending on the different ‘accessories,’ it has,” Shuhei Miyashita, a lecturer at the University of York, told Seeker.

Shuhei Miyashita worked on the project when he was at MIT’s Computer Science and Artificial Intelligence Lab. He and his colleagues describe Primer in a paper published this week in the journal Science Robotics.

The researchers were inspired by nature and the variety of life forms that undergo metamorphosis, including butterflies, moths, and beetles. They took a cue from hermit crabs that wear different objects as houses, which they collect from the local environment.

Bringing such transformative capabilities to the field of robotics could lend a new flexibility to otherwise rigid machines that are designed with a fixed structure and a defined purpose, which could make them more powerful and efficient.

Primer behaved something like a crab in the lab, scuttling around on a surface toward its exoskeleton. It’s a magnetic robot driven by an external electromagnetic field — similar to how a magnet will move another magnet when held close to it. Miyashita said that another source of power could propel Primer or even replace it as an engine, be it an electric motor, a protein, or a cell.

The exoskeletons are flat pieces of laminated polyester or polyvinyl chloride film —plastic, basically — and are designed with strategic creases and slits that produce a particular shape when folded. When heated to 65 degrees Celsius, they fold. In the experiments, the exoskeletons lay flat on small heating pads. Once Primer moved on top of an exoskeleton, it affixed itself to it by hooking onto a water-dissolvable latch. When heat was applied, the exoskeleton folded up around Primer, taking the shape of a wing, a ball, a boat, or a shovel.

Other exoskeletons could take the form of a drill, a water scoop, a cutter, or grabber, the authors write. To shed the exoskeleton, Primer moves into water, which dissolves the latch and frees the robot. In the case of the boat, the latch doesn’t contact the water.

The work builds on previous research lead by Miyashita’s adviser, MIT roboticist Daniela Rus, showing that robots could assemble themselves into different shapes and even fold into specific shapes.

Miyashita said that Primer isn’t limited to wearing sheets of conductive plastic. Just like the hermit crab, Primer can don an object from its environment, such as a leaf, to use it as a tool or for camouflage.

Flexible in design and capability, Primer’s future could go in any number of directions.

“This could one day have applications in many different areas, from deep-sea construction to disaster-relief operations,” said Miyashita. “This work shows that it’s possible to design a robot that can keep rewriting its abilities.”

The team is now working to make the robot even smaller and more intelligent, and exploring different types of materials to make it more durable.