For years, 3D printing has been hailed as an emerging technology likely to transform our lives. Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory have taken the nascent field to a new level with the creation of 3D printed robots made of both solids and liquids.

Previously, 3D printing had only been done with solid materials. Printing with both materials allows for the faster creation of complex designs, lessening the time and expense required to make robots. Inexpensive robots could make remote exploration — or any activity where a robot is used — more affordable, bringing broad implications for the utility of robots.

“It makes a big difference in what kind of machines you can make,” said professor Daniela Rus, who oversaw the project. “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.”

The MIT team used the method to print hydraulic bellows that were filled with fluid. After adding a battery, sensors and computer to their small hydraulic robots, the robots could walk independently.

Rus said her team plans to expand and improve its work before commercializing the technology. Their current process took 22 hours to create the six-legged, 1.5-pound robots with a commercially available 3D printer — costing more than $100,000 — that they modified.

The printer — a Stratasys Objet260 Connex — wasn’t built to use liquids in the 3D printing process. So the researchers essentially hacked the machine, inserting a different computer chip in the cartridge holding their liquid of choice — the machine’s cleaning fluid — so that the 3D printer thought it was actually printing plastic, not liquid.