The Cornell-developed robotic gripper that already boasts Internet fame and imitation has evolved: Now, it can throw things, without swinging an arm, by using air pressure to launch objects forward.
Researchers in the lab of Hod Lipson, associate professor of mechanical and aerospace engineering and of computing and information science, described their robotic gripper’s new capabilities online Jan. 30 in IEEE Transactions on Robotics, to appear later in print.
But it’s really best to see it in action. John Amend, the graduate student who works on the gripper as part of his Ph.D. thesis, has the prototype gripper attached to a robotic arm in the Cornell Creative Machines Lab. When programmed, it can pick up and toss objects at different speeds and trajectories. A video shows the gripper tossing balls, sorting tools into bins and hitting a dartboard bull’s-eye.
The gripper, a latex balloon filled with coffee grounds, bears down and hardens, due to evacuated air, around whatever object is being gripped and, when the air pressure is reversed, the object is released. Depending on the rate of the air pressurization, the object can be launched into the air.
"With the original version, resetting the gripper between grips was slow when we tried to pick up several things in a row," Amend said. "We decided to include positively pressurized air to try to solve that problem, and the shooting ability was an unexpected benefit."
The science behind the gripper is called the jamming transition, a physical phenomenon in which particles, in this case, coffee grounds, act like a fluid when loosely packed, and interlock like gears to solidify when compressed. Collaborators on the project at the University of Chicago, led by Heinrich Jaeger, study the physics of this jamming transition.
This simple idea that has created such a fuss among robotics enthusiasts has lots of commercial potential, but many questions remain, Lipson noted.