January 07, 2016      

Recombinant innovation

New York’s Hudson Valley is the only place in the world where you can see a 3D printer on wheels. If you spot one, look as well for the brainy inventor of the machine, Bob Flitsch, a 2015 graduate of Harvard’s John A. Paulson School of Engineering and Applied Sciences, who will probably be very close by.

Flitsch, put off by the boxy, stationary 3D printers from his undergraduate days, jammed one of these aforementioned boxy 3D printers smack dab into the undercarriage of an autonomous ground vehicle or AGV. Voila, from two new robots he made a third new robot, a 3D printer on wheels, or as he dubs the machine, the Addibot.


It’s what economist Paul Romer in his book The Nature of Technology calls “recombinant innovation.” It’s one of those occasions when we see how obvious and simple is the basic idea of it, yet how come no one thought of it?

Flitsch opened a business around his invention in the Hudson Valley, adding the corporate slogan: “Making the world a workspace.” Perfect.

Adam Zewe, the Paulson School’s communications manager, sat Flitsch down for an interview about his Addibot business, and then was kind enough to send it along to share with our readers.

We like Adam’s piece for both the inventiveness and practicality of the Addibot but also as a concrete example of Romer’s recombinant innovation thesis. Robotics is one of those places where there are machines aplenty to “recombine.” We hope to see many more in the future.

Here’s Adam:

Robert Flitsch, S.B. ’15, didn’t like being constrained by the boxy shape of the 3D printer he used while he was a student at the Harvard John A. Paulson School of Engineering and Applied Sciences. So this mechanical engineering concentrator developed a wheeled additive manufacturing machine that can literally run (or drive) circles around a traditional 3D printer.

He recently launched a startup named Addibots (a portmanteau of additive manufacturing and robots), to develop and market his mobile 3D printing robots.

“By making the additive manufacturing components completely mobile, you break free of all the workspace limitations of 3D printing,” Flitsch said. “But Addibots also greatly opens the field to many new application spaces for additive manufacturing.”

An Addibot is a mobile robot, either remote-controlled or autonomous, that holds an array of additive manufacturing print heads on its undercarriage. These high-resolution printheads enable the robot to 3D-print using different materials as it drives along a surface.

Ice was the surface Flitsch had in mind when he initially developed the concept. A lifelong hockey player, he conceived the additive manufacturing robot as an efficient tool to resurface an ice rink that has been chipped up by skates. For his senior project in Engineering Sciences 100, he built a prototype of an additive manufacturing robot that was able to extrude ice onto the surface of an uneven skating rink.

“I soon realized that the best thing about this technology is that it is really only limited by what you can think up,” he said.

After brainstorming other applications for Addibots, Flitsch decided to focus on road resurfacing.

He is currently prototyping an Addibot that would be able to move along a road at a constant speed, using a specialized injector array to resurface the road with a combination of different materials. The machine’s ability to streamline resurfacing work could help public works departments across the nation meet the massive demand for new and better roads.

He doesn’t see Addibots as a replacement for human workers, but rather as a way to improve roadwork and enable municipalities to perform routine maintenance, rather than spending additional time and tax dollars reactively filling potholes.

“Road resurfacing Addibots would also be a great way to move caustic materials, like tar, farther away from the people who would be working on the roads,” Flitsch said.

By incorporating different printheads into the injector array, the Addibot could easily augment resurfacing material with specialized elements, such as carbon nanotubes, which would improve road durability, Flitsch said. Eventually, the technology could even “print” sensors into the road surface that would be used by traveling autonomous vehicles.

Flitsch, who is currently seeking funding sources to advance his prototyping efforts, is hoping to bring an Addibot to market within one to three years. And he is considering other applications for mobile additive manufacturing robots.

“Once you get rid of that confined workspace and you make the world your workspace, there is no telling what you can do,” he said.

Adam Zewe
Communications Manager
Harvard John A. Paulson School of Engineering and Applied Sciences
[email protected]