How can you make a 7.6 cm (3 inch) wide soft robotic cube jump more than two-and-a-half times its height? 3-D print its hard parts, pour and cure its soft parts, and then wire it up with spring-loaded metal loops. MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) demonstrates how they made their autonomous soft robot cube in the video above.
Inside of the cube there are two motorized rotors that are each connected to one end of four flattened “tongues” (loops of spring steel). Activating the rotors causes the tongues to get pulled through rectangular openings into a round cavity inside the body of the robot. As the rotors continue to turn, the tongues keep getting more and more compressed, eventually getting pulled all the way around back to the openings. This causes them to spring out, simultaneously releasing a bundle of elastic energy that spurs the robot to jump.
The team originally tested a “hard version” of the robot, but found that the softer one could double its distance by bouncing along flat surfaces after landing. The cubes are totally self-contained, with integrated sensors, controllers, and rechargeable batteries.
This video shows more about how it works: