This Robot Uses Electrically-Charged Fingers To Delicately Move Things Around

One of the most problematic issues with robots is their ability to be flexible when grasping an object. I mean, have you ever tried that children's claw toy game?

Well, a new kind of robot solves that problem with static electricity to make its parts flexible, low-energy, and capable of lifting all kinds of different objects.

Grabit Inc. is making robots that rely on static charge to lift their prey - that's the same kind of electricity generated when rubbing a balloon against your head, making it stick against a wall. It's also what causes a doorknob to shock you or your hair to stand on end when you put on a fuzzy sweater.

The company, incorporated in 2011 as a spinoff of research institution SRI International, is making these robots specifically for the manufacturing and logistics industries, where most robots rely on mechanical claws, vacuum grippers, or suction cups to pick up objects and move them around. The static-electricity fingers on these robots are low-energy and more flexible than other approaches that robots use to pick stuff up.

Here's what it looks like in action:

The key is a process called "electroadhesion." Electroadhesion uses electrodes to generate positive and negative charges on a surface. When this surface touches another object, it induces charges in that surface as well. Particles with opposite charges are attracted to one another - much as the positive and negative ends of two magnets are attracted - and the surfaces stick together.

The amount of weight they can carry depends on the type of material the gripper is lifting. For example, the Grabit Gripper, a kind of panel handling gripper, can lift four grams per cubic centimeter of sheet metal when oriented horizontally, but only three grams per cubic centimeter of glass. This is because the atoms in metal and glass have different electrostatic characteristics and interact differently with the gripper.

There are several advantages to the Grabit method, according to CEO Charlie Duncheon. The first is high flexibility. Grabit grippers can handle a variety of different objects, while "mechanical grippers tend to be part specific," he says.

For example, Grabit's "panel handling" gripper, shown in the clips below, can lift a circuit board, a fabric square, and a mobile device with the same parts. It uses the same static electricity technology as the finger grippers above.

Another advantage, according to Duncheon, is that electroadhesion uses much less energy than other material handling methods - 1,000 times less than a typical vacuum gripper, he claims.

While Grabit is only focusing on using the technology for material handling, Duncheon says it has the potential for all kinds of other robotic applications. "You can consider everything from service robots, home car robots, healthcare robots - there's a broad range of other applications," he says.

Check out Grabit's demonstrations on their YouTube channel.