James Pikul, assistant professor in Penn Engineering’s Department of Mechanical Engineering and Applied Mechanics, has developed a environmentally controlled voltage source, or ECVS. It works like a battery, in that the energy is produced by repeatedly breaking and forming chemical bonds, but it escapes the weight paradox by finding those chemical bonds in the robot’s environment, like a harvester. While in contact with a metal surface, an ECVS unit catalyzes an oxidation reaction with the surrounding air, powering the robot with the freed electrons.