Researchers have created a robot that combines the strengths of both soft and rigid materials, allowing it to leap explosively into the air. The multi-university team was looking into using butane explosions to move a robot, and found that while a rigid body made for a good jump, it also cracked after only a few hops. A fully soft-bodied robot would probably just flop around on the ground. So using a 3-D printer, the team made a combination of both, with the harder part at the top smoothly transitioning to a soft, flexible lower area.
The result was a robot that didn't jump as high but lasted more than 10 times as long, making 100 hops before breaking. It's nothing you'll be seeing at home or on the battlefield any time soon, but the team successfully showed that when you're building a robot, you don't have to make a binary choice between "hard" and "soft" — even for individual parts. After all, nature doesn't build things that way.
More complex gradients between hard and soft, or greater differences in the give of the materials, could further improve the flexibility of this method. Led by Harvard's Nicholas Bartlett and Michael Tolley of the University of California, San Diego, the team's study appears in this week's issue of the journal Science.