This squishy robot uses explosions to jump

Roboticists from Harvard University and the University of California in San Diego have built a robot with a 3D-printed body that transitions from a hard core to a softer exterior. Oh, and it uses explosions to leap into the air.

There's plenty of research into soft robots, which are safer to work with than their more rigid companions. But soft robots also tend to be much slower at accomplishing tasks - so the team wanted to combine a rigid centre with a squishy exterior for the best of both worlds.

This robot's task? Jumping in the air over and over again. A rigid enclosure makes for higher jumps, but a soft one lets it survive the landing better. So the team 3D-printed a flexible hemisphere, like half a basketball, to act as the bottom and enclosed the circuitry and battery in a rigid upper hemisphere.

Inspired by nature

The jumping is accomplished with the help of a butane-oxygen mix that's injected into the lower chamber. Once ignited, the gases explode and propel the robot upwards. During testing it was able to jump 0.75m into the air more than 100 times, and survived an additional 35 falls from a height of more than a metre.

Its creator, Michael Tolley, said that the idea came from the animal kingdom. "In nature, complexity has a very low cost," Tolley said. "Using new manufacturing techniques like 3D printing, we're trying to translate this to robotics."

Details of the design of the robot were published in Science magazine.