3D printed STAR bot sprawls down and goes under doorways Drawing inspiration from insects, The STAR (Sprawl Tuned Autonomous Robot) created by David Zarrouk, Andrew Pullin, Nick Kohut and Ronald Fearing at the Biomimetic Millisystems Lab, UC Berkeley, has six legs and can control its sprawl angle which allows him to perform many maneuvers to overcome obstacles. Contact angle and normal contact forces are substantially reduced when the sprawl angle is low, and the velocity increases over smooth surfaces. So the robot can sprawl down and go under a door and then sprawls up to walk normally. STAR at different sprawl angles. a) Positive sprawl angle. b) Zero sprawl angle. c) Negative sprawl angle.STAR is designed for rapid manufacturing. Each component of the STAR, the body core, motor housing, spur gears, and leg were built using a ProJet 3000 3D printer (except the electronics). The printer's accuracy is roughly 0.05mm. The robot is designed for easy assembly and simple part replacement, and the total mechanical assembly requires roughly 30 minutes. STAR can run at all speeds up to 5.2m/s (43 body lengths per second) on smooth surfaces while steering is on (i.e. it can be controlled to run in straight line or turn). The legs slide to the side in order to reduce collisions with the ground which allow for better stability and steering control.