"We demonstrated this process by building a robot that folds itself and walks away without human assistance," said Sam Felton, a Ph.D. candidate at Harvard University's School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering and the lead author of the study, featured in the latest edition of the journal Science.
The robots have been dubbed Origami robots because their self-assemblage is more like self-folding. The robot starts out flat, but embedded in the thin sheet are creases made of a polymer that bend on their own when heated.
"The exciting thing here is that you create this device that has computation embedded in the flat, printed version," explained Daniela Rus, an MIT researcher who helped create the Origami robots. "And when these devices lift up from the ground into the third dimension, they do it in a thoughtful way."
Rus and her colleagues previously built self-assembling modular cube robots called M-Blocks as well as a robot that sprang to life when it was baked in the oven. The latest research builds on that easy-bake robot, only this time the heat is delivered via electric circuits.
"That's exciting from a geometry standpoint," MIT researcher Erik Demaine said, "because it lets us fold more things. Because we can do the sequencing, we have a lot more control. And it lets us make active folding structures. Instead of just self-assembly, you can then make it walk."
Though the robot starts flat, it is actually five separate layers of materials: a middle copper layer, two structural layers of paper, and then two outer layers made of shape-memory polymer (the part that folds when heated).
The idea is to be able to create something complex through simple methods and using lightweight, easily transportable material. Researchers say, with the Origami robot, they've done just that.
"These robots are inexpensive and [their] layered composites can be built faster than equivalent 3-D printed structures," Felton said.