The study, A 3D-Printed, Functionally Graded Soft Robot Powered by Combustion, which was highlighted by Harvard Gazette Magazine today, was authored by a group of microrobotics engineers and led by Harvard's School of Engineering and Applied Sciences. In it, the authors introduce us to a little robot that can hop -- which isn't particularly noteworthy, of course. What's really interesting is almost every other aspect of the 'bot, from its soft 3D-printed body to the fact that it's powered by a reaction between butane and oxygen.
You see, soft and hard robot have very different strengths and weaknesses. Robots with hard internals are fast -- their mechanical parts let them move quickly -- but they're also fragile. Soft robots (like the ones we recently saw at Carnegie Mellon's robotics lab) are very durable, since they can stretch and deform without breaking, but they're slow. Here's a great example of one of these very sturdy but exceedingly slow-moving 'bots, as Harvard shows us:
I'm fine, guys! Fine!
Sturdy but slow, right? Well, the authors of the new Science paper explain that they wanted to build a 'bot that could combine the strengths of both species of robot. The internal core of their bot -- where all the electronics reside -- is hard. But the externals are soft, made out of a flexible, 3D-printed plastic that deforms when under stress to act as a kind of shock for the fragile interior. Not unlike the way our muscles and tendons provide shocks for our bones.
This blooper got 1.2 million views on BotTube.com.
So, what powers its hopping? That would be three pneumatic legs, which inflate to tilt the body towards its intended target. To actually power the hop, though, butane and oxygen are ignited to create a brief, sudden burst of power -- which propels it up to six times its own height. As the LA Times points out, the fact that a chemical reaction powers it -- as opposed to an external energy source -- means it would be a perfect candidate for a rescue robot, since current rescue 'bots are limited by how they get their power.
As one of the authors tells the Gazette, its power and its ability to survive catastrophic falls make it a unique meld of hard and soft robotics: "The wonderful thing about soft robots is that they lend themselves nicely to abuse," co-author Nicholas Bartlett says in the story. In fact, the Harvard story even demonstrates some of that abuse, above. Check out the full video below.