Creating Self-Folding Origami Robots

Sam Felton envi­sions a world in which tem­po­rary housing would autonomously con­structed, and origami robots would fold them­selves into 3-​​D machines for space explo­ration. Based on the research he’s done—and the origami robots he’s already built—his vision might not be as far-​​fetched as it would seem.

Felton joined North­eastern this fall as an assis­tant pro­fessor in the Col­lege of Engi­neering, after earning his doc­torate in mechan­ical engi­neering from Har­vard Uni­ver­sity. There, he worked with a research team focused on cre­ating print­able, fold­able robots, with an eye toward get­ting them to fold themselves.

“We were able to make things that could walk on their own, but we weren’t just inter­ested in building a single self-​​folding item,” Felton said. “The idea is to push the bound­aries of what’s pos­sible in self-​​folding structures.”

Now, the chal­lenge is to build them so they can unfold as well.

Felton was the lead author on a paper pub­lished in the journal Sci­ence, which explored the method he and his col­lab­o­ra­tors estab­lished for building self-​​folding machines. The idea is based on origami, the Japanese art of paper folding.

Appro­pri­ately, his robots are made of paper—though the paper is sand­wiched between layers of pre-​​stretched poly­styrene. Any toy afi­cionado might rec­og­nize the pre-​​stretched poly­styrene, as it’s the same mate­rial that makes up the pop­ular Shrinky Dinks toy.

With the toy, chil­dren draw on large pieces of flex­ible sheets that are then placed into the oven to shrink down and harden into trinkets.

The self-​​folding robots use a sim­ilar heat-​​contracting mech­a­nism. Strips of copper are placed along the fold lines of the robot. Microchips installed on the robot send elec­tric cur­rent through the copper, making them heat up. When that hap­pens, the poly­styrene mate­rial con­tracts, causing the joint to buckle and fold.

Felton’s newest chal­lenge is finding a way to “scale up” the robots, which means get­ting away from using heat as the cat­a­lyst for folding.

“Now we’re looking at hydraulics, pneu­matics, and chem­ical reac­tions,” Felton said.

The robots, he explained, could be used in a number of dif­ferent ways.

“There are a lot of dif­ferent options for them—the cur­rent research seems to be pushing for doing stuff at the micro scale, so get­ting the robot to fold itself is the only way to form these shapes,” Felton said.

“But I’m really inter­ested in expanding it to the very large scale, where it could be useful both for archi­tec­ture and build­ings that could assemble them­selves as well as for space explo­ration, where it’s very dif­fi­cult to trans­port stuff up into orbit. So if you could com­pact the robot down by folding it up and then having it assemble itself, you could save a lot in cost and manpower.”

Felton envi­sions the build­ings being used as tem­po­rary shelter in places recov­ering from dis­aster. It’s a futur­istic idea, he said, but that’s exactly the point.

“Purely from a research stand­point, a lot of it is this pie in the sky stuff—if it were pos­sible right now, in the short term, there would be a com­pany already doing it,” Felton said. “So you have to pick these huge goals and work back­ward and figure out what the first step is.”