Researchers at the Massachusetts Institute of Technology have been making 3D printed robots from both solids and liquids. It seems like many moons ago that 3D printing technology was hailed as something that would revolutionize the world. While progress has been slower than some people expected, 3D printing has been put to good use by the scientists at MIT.

MIT Using 3D Printing To Make Robots

MIT scientists combine liquid and solid in 3D printing

Researchers at the MIT Computer Science and Artificial Intelligence Laboratory have come up with a way to 3D print using solids and liquids. The technology had only previously been used with solid materials.

Now that liquids can also be used, researchers can print complex designs far faster making robots less time consuming and less expensive to produce. If we can drive down the cost of making robots we could start using them in many different fields.

“The ability of printing solids and liquids at the same time will enable us to create a whole different class of active mechanisms,” said professor Daniela Rus, who oversaw the project. “The idea of reducing or simplifying the amount of manual assembly that’s required to create robots is really critical for getting broader adoption of robots, and making them more accessible.”

“It makes a big difference in what kind of machines you can make,” said Rus. “If you can make complex robots really fast — print them like you print a piece of paper — you can imagine not having to worry so much about whether you lost your robot.”

Modified commercial 3D printer used in research

The team used 3D printing to make hydraulic bellows filled with fluid. They later made the robots walk independently after fitting a battery, sensors and a computer to the small units.

With further work Rus says that the concept could be expanded and improved before it is commercialized. The robot took 22 hours to create, features 6 legs and weighs in at 1.5 pounds. The team used a commercial 3D printer worth over $100,000 in the experiment.

The printer, a Stratasys Objet260 Connex, was modified so that it could use liquids in the 3D printing process. In order to make it possible the researchers had to hack the machine and insert a different chip in the cartridge which held the liquid. By hacking the machine they made it think that the cartridge contained plastic, not liquid.

The “printable hydraulics” method builds layers of material one drop at a time, measuring half the width of human hair. Once each layer is in place it is solidified by a high-intensity UV light which leaves the appropriate sections as liquid.

Making robots for dummies

“Right now it takes years to make any kind of robot. You need to be an expert in mechanics, electronics, computation, software; you need a lot of expertise,” says Rus. “With this tool you can think of your robot at a higher level, and can print the whole body without manually having to assemble it.”

It is also easier to prototype using 3D printing. You can experiment with different robot configurations at minimal financial cost in a short space of time. The way we build robots could completely change.

“If you look at a traditional robot, something that’s designed and built in a conventional way, the designer of that robot has embedded all kinds of choices about the eventual fabrication approach that will be used,” says postdoctoral associate Robert MacCurdy. “We think that by coming up with a method that decouples the cost of fabricating from the design, we can enable new applications that we haven’t even dreamed of.”