Robots that can already stand, walk and wriggle under obstacles are getting a new skill thanks to Harvard University researchers -- now they can jump.

The researchers have used small explosions produced by a mix of methane and oxygen to allow a soft robot to leap as much as a foot in the air, the university reported Thursday.

That ability could one day prove useful in allowing robots to avoid obstacles during search and rescue operations, they said.

"Initially, our soft robot systems used pneumatic pressure to actuate," said Robert Shepherd, a former postdoctoral researcher at Harvard who is now an assistant professor at Cornell University.

"While that system worked, it was rather slow -- it took on the order of a second. Using combustion, however, allows us to actuate the robots very fast. We were able to measure the speed of the robot's jump at 4 meters per second."

The soft robots are molded using soft silicone that allows them to stretch and flex.

The robots are connected to tubes that deliver a precisely controlled mix of methane and oxygen, ignited by high-voltage wires embedded in each leg of the robot.

"Because it releases so much energy so fast, it made sense for jumping to be the first 'gait' we explored with this system," Shepherd said. "The next step now is to learn how we can use this combustion system for other gaits, like running or even walking."