Mechanical engineers from MIT have designed an interface that takes advantage of a human's split-second reflexes, allowing a humanoid to maintain its balance and complete tasks. A two-legged robot named HERMES, outfitted with load sensors, can punch through drywall, smash soda cans, and karate-chop boards in half, but its actions are not its own. A few feet away, MIT Ph.D. student Joao Ramos stands on a platform, wearing an exoskeleton of wires and motors. As Ramos mimes punching through a wall, the robot does the same. When the robot’s fist hits the wall, Ramos feels a jolt at his waist. By reflex, he leans back against the jolt, causing the robot to rock back, effectively balancing the robot against the force of its punch. The exercises are meant to demonstrate the robot’s unique balance-feedback interface.