Universal Robotic Gripper

Coffee grounds in a balloon drawing a vacuum

University of Chicago, Cornell researchers develop universal robotic gripper


That just may trump the roller claw.

very nice…probably coarse grind…expresso grind tends to stick

Seems like an adaptation of the suction cup to better distribute vacuum force over objects with uneven surfaces. I want to play with it, and see how much better it holds various objects compared to suction cups. I wonder how feasible this is in FRC.

This is so cool!


Reminds me of the jammer: http://www.youtube.com/watch?v=SbqHERKdlK8

I don’t believe it is applying suction to the object in the traditional sense as with a suction cup. That would imply that the balloon material is porous, and that would leak vacuum all over. If I correctly interpret what is happening, the vacuum inside the balloon is causing the balloon material to constrict around the object, with the resulting friction causing it to “grip.” Notice all objects are 3D, not flat, and that they force the balloon around the object before gripping it. Great example of an totally new idea.

Now here’s what I’m wondering, could we legally use it on a FIRST robot? If FIRST ever made a game with small objects this could be useful…

I think the balloon is porous because of the sounds in the video.

It might not be porous, but if it isn’t I don’t think some of those objects would stay against it. The egg and the small items in particular.

We were only required to use those delrin wheels in 2009…let’s see what rules await us in January!

Nope, the surface is not porous. It is grippy. It picks up the egg in much the same way you would, by squeezing it.

My son had a “Vac Man” toy (made by the same company that sold “Stretch Armstrong”) that works along the same principles. Based on what it could do, I can imagine a much fancier universal gripper having “fingers” that might be capable of handling smaller or more delicate objects, or even curling into hooks to lift things with handles.

The press release says it’s a latex party balloon, so definitely not porous.

And yes, probably a coarse grind since it depends on the material locking together when compressed.

I’m awestruck. Simple. Elegant. I would never have thought of this.

I’m at a loss as to how one should calculate grip force with that. Anyone have any ideas?

The good ol’ fashioned method of picking up heavier weights until the weights started falling would probably be the least-painful way for most of us to figure it out. It all depends on the friction of the balloon, tensile strength of the balloon, and I’m sure the vacuum plays a large part in it too. Then we’d have to consider the angle of grip as well.

In a similar fashion…pick up an object, place a load cell or some kind of spring gauge on the object in the gripper and pull til it pops out. That will give you an idea for that particular object. The gripping force would obviously vary from object to object.


It seems to me that grip force would be essentially independent of the balloon. The only relevant factors I can think of immediately are the amount of “shrinkage” of the filler material when vacuum is applied, and the stability (probably shear strength, mostly) of the vacuum-compacted material.

(The friction of the balloon definitely matters when you try to figure how much weight you can pick up with a given grip force, of course.)

We could use this for VEX Round-up right now !

My thoughts would be that you need to find the surface area of contact with the balloon, the coefficient of friction between the balloon and object, and finally the force with which the vacuum is pulling the balloon in. Then from there you would be able to calculate the force with which the object will be held, however those are my initial thoughts which I feel are far off from what you would actually need in order to calculate the force.

I would think it would vary GREATLY from grip to grip as well. I wish our team had build a suction cup at some point so I could go play with this concept and learn more.

If you’re serious about using this, I’d think that the coffee bean usage is a clear violation of the no food in the pits policy :stuck_out_tongue:

Actually, how well would this work with styrofoam pellets? Does this require that the material inside the balloon not compress?

The granules must not compress in the vacuum for this type of manipulator to work (well).