MIT Engineers Have 3D-Printed A Walking Robot With A Liquid Center

The future bellows

Small MIT Soft Robot

Small MIT Soft Robot

It was entirely 3D printed, except for the few parts that weren't.MIT CSAIL

We watched the birth of the new machines. Planned in labs, the 3D printer gave them form, layering their bodies into being. The robots were softer than the ones we’d come to fear, their gently wriggling bodies more caterpillar than Terminator. Once it was removed from its mechanical womb, the creators hooked up some batteries and gave it the spark of life. And with that, it was off, walking into the world:

Made by MIT’s Computer Science and Artificial Intelligence Lab, this robot walks with hydraulic bellows, fluid pumping in and out to turn a crankshaft that moves the legs back and forth. All parts of the robot, apart from the batteries, wires, and motor, are 3D printed. That includes the liquid inside the bellows, which remains liquid while the rest of the body is solidified in printing.

Here’s how MIT describes the process:

With “printable hydraulics,” an inkjet printer deposits individual droplets of material that are each 20 to 30 microns in diameter, or less than half the width of a human hair. The printer proceeds layer-by-layer from the bottom up. For each layer, the printer deposits different materials in different parts, and then uses high-intensity UV light to solidify all of the materials (minus, of course, the liquids). The printer uses multiple materials, though at a more basic level each layer consist of a “photopolymer,” which is a solid, and “a non-curing material,” which is a liquid.

The robot, as well as a 3D-printed soft hydraulic finger and claw, can be seen in action in the video below, and the full paper is here: