UCSD grad students Christopher Schmidt-Wetekam and David Zhang solved the problem with three innovations. The first is the spring-loaded mechanism that allows it to jump—basically a simpler version of the mechanism that turns the windshield wipers on late-model cars. The second is a combination accelerometer-gyroscope that keeps the ‘bot stable. Finally, “reaction wheels” keep it upright by constantly torquing in the direction the robot is most likely to fall. The resulting robot, iHop, can roll along like a car when the path is clear and then hop over obstacles. Schmidt-Wetekam says iHop could search dangerous environments—say, a burning apartment building—and direct human rescue crews toward survivors. WHAT’S NEXT Search-and-rescue aside, iHop begs to be made into a toy. The robot’s inventors are looking for partners in both industries.