Meet MobiPrint: A Mobile 3D Printer that Can Automatically Measure a Room and Print to the Specs

University of Washington researchers have created MobiPrint, a mobile 3D printer that can automatically measure a room and print objects onto its floor. The team’s graphic interface lets users design objects for a space that the robot has mapped out. The prototype, which the team built on a modified consumer vacuum robot, can add accessibility features, home customizations or artistic flourishes to a space.

“Digital fabrication, like 3D printing, is pretty mature at this point,” said Daniel Campos Zamora, Doctoral Student in the Paul G. Allen School of Computer Science & Engineering. “Now we’re asking: How can we push it further and further into the world, and lower the barriers for people to use it? How can we change the built environment and tailor spaces for peoples’ specific needs — for accessibility, for taste?”

The prototype system can add accessibility features, such as tactile markers for blind and low-vision people. These might provide information, such as text telling conference attendees where to go, or warn of dangers such as staircases. Or it can create a ramp to cover an uneven flooring transition. MobiPrint also allows users to create custom objects, such as small art pieces up to three inches tall.

Before printing an object, MobiPrint autonomously roams an indoor space and uses LiDAR to map it. The team’s design tool then converts this map into an interactive canvas. The user then can select a model from the MobiPrint library — a cat food bowl, for instance — or upload a design. Next, the user picks a location on the map to print the object, working with the design interface to scale and position the job. Finally, the robot moves to the location and prints the object directly onto the floor.

For printing, the current design uses a bioplastic common in 3D printing called PLA. The researchers are working to have MobiPrint remove objects it’s printed and potentially recycle the plastic. They’re also interested in exploring the possibilities of robots that print on other surfaces (such as tabletops or walls), in other environments (such as outdoors), and with other materials (such as concrete).

Here is an exclusive Tech Briefs interview, edited for length and clarity, with Zamora.

Tech Briefs: What was the biggest technical challenge you faced while developing MobiPrint?

Zamora: I think it’s two parts. One of the challenges is just, mechanically, how do you edit, how do you try to handle or tweak a 3D printer to reach and print on the floor? What does that mean for making a system untethered? So, just figuring out the mechanics of editing or the mechanical changes to the 3D printer, but also figuring out what does that mean for the 3D printing? Like slicers and the settings so that you're printing now on this weaker kind of a structural loop, which isn't as tight as you might have in a conventional 3D printer.

I think the software, a lot of it, ended up being one of the challenges, too. What does the interface look like? How do you integrate the robot's movement into some sort of user interface that you can use to manipulate the prints.

Tech Briefs: How did this project come about? What was the catalyst for your work?

Zamora: This project came about through one of the applications that we had in paper about tactile service indicators. So, these are like directional guides for people who are blind and low-vision. My lab does a lot of work in accessibility, and so we were already kind of working in the accessibility space, looking at how we can use digital fabrication tools to kind of augment and adapt the environment for people who are blind and low-vision potentially, especially in indoor places that might shift around like conference centers or things where it's hard to have that permanent installation of those bumps and tiles that you see.

We did a bunch of exploration in my first year, just looking at other fabrication techniques, like CNC milling, molding, like vacuum forming everything. Then we settled on 3D printing. And then, to make that possible, we kind of had to step back and make an entire mobile 3D printer and figure what that looks like.

Tech Briefs: Can you explain in simple terms how MobiPrint works?

Zamora: MobiPrint works by combining the locomotion and mapping abilities of a vacuum robot with an edited and tweaked 3D printer. So my system, like the design tool, communicates between both systems and allows additional integration. So, you can map out a space using the robot; that map gets converted into essentially an HTML canvas or design element. That's the canvas that people can use to place and edit 3D prints. Once they have that, then the robot will actually go out, navigate independently of it, and then use the 3D printing slicing tweaks that we've made to print directly on the floor.

Tech Briefs: Do you have any further research, work, etc. on the horizon?

Zamora: Right now, the immediate next steps for the system are looking at how to integrate more environmental information into the design process. Right now, we're focusing on a design tool and not necessarily another machine iteration, but that question of removal and integration is really important. And there I do have some work on designing for decay or growth over time so that the objects that you put in place, like once you put them in the environment, the question of how long are these things going to be there for? How permanent are they? How do they get removed? Is much more important.

So, there's no concrete plans right now because I think that needs to get integrated into a bigger design goal or contribution from a research perspective of ‘how do you design for objects that are transient?’ But, right now, the next focus is on ‘how do you enhance the design process?’ My Co-Author, Liang He, does have plans to print on walls using a different system. So, it's kind of like there is some work in that line as well, but my next steps are just focusing on the design part.

Tech Briefs: Do you have any updates you can share?

Zamora: I am working on putting together a more comprehensive guide on how to assemble it. I plan on making that assembly guide, open-sourcing the mechanical, like the 3D printing parts that I had to edit, so that if somebody's crazy enough to want to build something, they could do it.

This is all research, but, you know, I think one thing that's been surprising, and I guess it's an update for me, is just how much interest there have been from people in the 3D printing community of doing something like this. Because it is a radically different thing, right? I understand that it's kind of this far out vision of having 3D printers out there, but there's a lot of genuine interest. We’ve found that people are attracted to the project. So, I think I will want to support that and release all the files and hopefully people can learn from all the work that I had to troubleshoot and work if they want to play around with a similar system.

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