Scientists 3D print a robot that walks away when complete
Scientists at Massachusetts Institute of Technology's Computer Science and Artificial Intelligence Laboratory figured out how to hack a Stratasys 3D printer so that it not only prints the hard and flexible materials necessary for mobile robots, but also simultaneously adds in fluid to create working hydraulics, giving them the ability to print an entire, working hydraulic-actuated robot in one 3D print pass.
The scientists' work on the walking and slightly creepy hexapod robot (and other 3D printed hydraulics) is detailed in a new paper just submitted to IEEE International Conference on Robotics and Automation. It describes how they hacked a 3D printer to accept fluid as a working material by replacing a built-in RFID chip for what is basically the printer’s cleaning fluid with a chip that identifies the liquid as a printable material.
The Stratasys Objet260 Connex printer they used typically prints a gel that hardens when exposed to a special UV light. Since the cleaning fluid is unaffected by the UV light, it could be deposited by the print head inside the printed hydraulic chambers as they were printed. In this way, the printer could produce a fully functioning hydraulic component in one pass. The printer was also able to simultaneously print material of various hardness to give the robot both the rigidity (for the body frame) and flexibility (for the hydraulic bellows) it needs to function.
According to the paper, robots printed using this method do not need assembly or even the introduction of fluid-post production. As a result, there was no need to purge air bubbles from the hydraulic chambers, which could be printed can be completely sealed. Hydraulics work by using pressure and a fully sealed system should be stronger and more efficient than one assembled by hand.
Using this same 3D printing methodology, the researchers were able to 3D print a gear-pump (in one print pass), and soft, flexible grippers.
There are still some challenges to work through as the paper notes that this printing technique sacrifices strength, lifetime fatigue and even the overall resolution of parts. Even so, the ability to print a robot with working hydraulics in one pass is a notable accomplishment with many long-range implications in everything from disposable robotics to industrial manufacturing.
