The grippers are made from a rubber balloon filled with coffee grounds. The coffee grounds are a granular medium (made from grains… small solid pieces), and when one removes the air the coffee grains pack together and become extremely rigid, which is a process called granular jamming. This enables the gripper to grasp and hold on to objects of any shape. The jamming transition is considered to be a new type of phase transition similar to the glass transition that occurs when liquid glass is cooled.
What is amazing to me is that by rapidly forcing air back into the balloon, the gripper expels the object—basically throwing it! It is pretty amazing to see such a simple gripper throwing a ball or even darts!
Boston Dynamics funded by DARPA’s Maximum Mobility and Manipulation program have released videos of their new robot “Cheetah” which can gallop at 18 miles per hour (30 kph)! This sets the land speed record for legged robots.
Notice how the robot flexes its back while running just like living quadrupeds. Compare this with the video below of a living Cheetah…
While still a far cry from the 70 mph top speed of a living Cheetah, this robot lives up to the punch line of that old joke: I don’t have to run faster than the bear, I just have to run faster than you!
The Universal Jamming Grippers consists of a balloon filled with sand or coffee grounds. When slightly inflated it can wrap itself around an object. Then when the air is removed the balloon tightens its grip and holds tight.
Universal Jamming Grippers in Action Picking up a Glass of Water