|Credit: John Amend, Cornell University|
You’ll notice something striking about this particular robotic arm. Unlike other models, this design has no fingers or claw. In fact, it’s just a bag. Yet, it can somehow grip any kind of object. How?
The bag is filled with small grains. For their prototype, the authors used a balloon filled with coffee grounds. The bag is then attached to a vacuum. When that vacuum is turned off, the coffee grounds are packed loosely enough to mold around objects. Then, when the vacuum is turned on, the air is evacuated from the balloon leaving the coffee grounds rigidly compressed in place around the gripped object.
You can see a demonstration below:
Didn’t I tell you you were going to want one? Well, the good news is that you can make your own universal gripper! Here’s one tutorial:
Eric Brown, Nicholas Rodenberg, John Amend, Annan Mozeika, Erik Steltz, Mitchell R. Zakin, Hod Lipson, & Heinrich M. Jaeger (2010). Universal Robotic Gripper based on the Jamming of Granular Material Proceedings of the National Academy of Sciences 107, (44) 18809-18814 (2010) arXiv: 1009.4444v2.