This 3-D hexapod robot moves via a single motor, which spins a crankshaft that pumps fluid to the robot’s legs. Besides the motor and battery, every component is printed in a single step with no assembly required. Among the robot’s key parts are several sets of “bellows” 3-D printed directly into its body. To propel the robot, the bellows uses fluid pressure that is translated into a mechanical force. (As an alternative to the bellows, the team also demonstrated they could 3-D print a gear pump that can produce continuous fluid flow.) Read More.