Sandia National Laboratories researcher Gary Fischer with one of the combustion-powered hopping robots developed by Sandia for the Defense Advanced Research Projects Agency. The combustion chamber fires, the piston punches the ground, and the hopper leaps. The hopper jumps about 3 feet in the air and 6 feet from its starting point on each jump and, theoretically, could last about 4,000 hops on a single tank of gas, which is about 20 grams of fuel. Each hopping cycle is about 5 seconds. Another hopper, about the size of a coffee can, jumps 10 to 20 feet in the air and theoretically could go 100 hops on a tank of fuel.
Several patents are pending on the inventions.
It wasn't easy. Recalling his youthful experience launching tennis balls out of a tube using lighter fluid, Fischer first suggested that evaporated fuels might provide power needed for high hops. At one point the Sandia research team had set a goal of simply achieving atmospheric combustion in a small piston chamber. When we finally made it fall over, we were happy. The hopper leaps about three feet high on each jump and could travel as far as five miles on a tank of gas.