Printable robots — those that can be assembled from parts produced by 3-D printers — have long been a topic of research in the lab of Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT.

At this year’s IEEE International Conference on Robotics and Automation, Rus’ group and its collaborators introduce a new wrinkle on the idea: bakable robots.

In two new papers, the researchers demonstrate the promise of printable robotic components that, when heated, automatically fold into prescribed three-dimensional configurations.

One paper describes a system that takes a digital specification of a 3-D shape — such as a computer-aided design, or CAD, file — and generates the 2-D patterns that would enable a piece of plastic to reproduce it through self-folding.

The other paper explains how to build electrical components from self-folding laser-cut materials. The researchers present designs for resistors, inductors, and capacitors, as well as sensors and actuators — the electromechanical “muscles” that enable robots’ movements.

“We have this big dream of the hardware compiler, where you can specify, ‘I want a robot that will play with my cat,’ or ‘I want a robot that will clean the floor,’ and from this high-level specification, you actually generate a working device,” said Rus. “So far, we have tackled some subproblems in the space, and one of the subproblems is this end-to-end system where you have a picture, and at the other end, you have an object that realizes that picture. And the same mathematical models and principles that we use in this pipeline we also use to create these folded electronics.”

The key difference in the new work, explained Shuhei Miyashita, a co-author on both papers, is a technique for precisely controlling the angles at which a heated sheet folds. To create a robot, a sheet of polyvinyl chloride (PVC) is placed between two films of a rigid polyester riddled with slits of different widths. When heated, the PVC contracts, and the slits close. Where edges of the polyester film press up against each other, they deform the PVC.

But producing the pattern of slits is not as simple as just overlaying them on an origami crease pattern and adjusting the widths accordingly. “You’re doing this really complicated global control that moves every edge in the system at the same time,” said Rus. “You want to design those edges in such a way that the result of composing all these motions, which actually interfere with each other, leads to the correct geometric structure.”

Robotic self assembly systems could have a major impact on the manufacturing industry and the presence of robots in the modern world. As 3D printing technology continues to become more accessible, and subsequently robots become easier to produce because of it, before too long robots may be running the factories that forged them.