What’s most impressive about Carnegie Mellon’s new bot is its speed, versatility, and payload capability. In the video, you can see that it travels up to 20 body-lengths per second and has a payload capacity of roughly 5x it’s weight. The robot can even climb different sized tubes, although at different rates. It’s simple motor turns an unbalanced mass at a uniform velocity. As the mass swings around, it causes the robot to bounce back and forth between the tube walls. Two rubber o-rings let the researches specify the exact contact points and increase friction with the walls.
Earlier designs relied on fibers or bristles to create anisotropic friction with the walls and vibration caused motion in the direction of lowest friction. The problem with these designs comes when you need to remove the robot–now you’re forced to work against the maximum friction.