When he was 13, almost finished his degree at Dalhousie, Erik Demaine told The Chronicle Herald that “a computer is like a toy.”

Twenty years later, the Halifax-born math and science prodigy doesn’t sound so different.

“It’s been this ongoing project called printable robots,” Demaine said this week, starting to explain the most recent paper he co-authored.

“Our first collaboration was to make a sheet of material that could fold itself into multiple different forms, like origami,” he said during a phone interview from Japan.

“So it could fold into a paper airplane or into a paper boat.”

Now 33, Demaine and fellow scientists have found a way to make origami creatures not only fold themselves but come “alive” — crawling, turning corners and one day, he hopes, performing lifesaving tasks.

Most importantly, the robots come cheap since they take shape from a two-dimensional sheet and can be printed.

Demaine left Halifax when he was 14 for graduate school at the University of Waterloo. At 20, he became the youngest-ever professor at the Massachusetts Institute of Technology, where he is still based. A couple of years later, he won a MacArthur Fellowship, otherwise known as a “genius grant.”

The self-propelled origami project started a few years after that, and the proof of concept was finally published last week in the journal Science.

The robots are made from a combination of paper and a type of plastic often used in a children’s toy known as Shrinky Dinks. It shrinks and hardens when heated.

The team of researchers demonstrated last week how they can design and print each sheet, then attach batteries, motors and a microcontroller. When they send heat through the sheet, it transforms.

“By placing that (shrinking plastic) essentially along the crease lines, you can get it to pull the creases shut to a desired angle,” said Demaine, who was the mathematician on the project.

“There’s a circuit that can trigger different creases to heat up at different times and get a sequence of folding operations to happen.”

The whole process takes about four minutes, and then the robot scuttles away. Each one costs about $100.

Demaine has long been fascinated by origami and the math behind it.

But the new invention, created with a longtime team in Boston, was inspired by another kind of play, too — the wish to play with robots, which are usually too expensive for constant experimentation.

“Traditionally, it takes years to build a robot and you’re kind of stuck with what you have,” said Demaine.

“Here you can imagine, every day, making a new one to deal with the imperfections of your previous design. You can imagine much more disposable robots, like bomb diffusion, minefield detection.

“The current robots that are doing that cost millions of dollars. If you could do it with a tens-of-dollars robot, it would be a big win.”

In the future, maybe microscopic folded robots could be used in medicine, he said. But with the chance to try out a new design every day, it’s hard to predict what could come.

“There can be one robot per child in a school,” Demaine said. “You can imagine each child designing their own custom robot that does different things.”

Demaine said he still visits his mother in Herring Cove every year, and his time as a preteen undergrad at Dalhousie “paved the way” for the rest of his career.

A former supervisor there said he wasn’t at all surprised to hear of Demaine’s latest accomplishment.

“My first memory of Erik is that of this young 12-year-old kid with his dad walking into my class of 100 students,” said computer science professor Srinivas Sampalli.

Demaine aced every course and graduated in two years, also co-authoring two journal papers with Sampalli in the process, said the professor.

“I recognize him as one of my brightest students ever.”