Soft Robotic Fingers Use Electroadhesion for a Gentle Touch


EPFL scientists have developed a new soft robotic gripper - made out of rubber and stretchable electrodes - that can bend and pick up delicate objects like eggs, water balloons, and paper. It uses electroadhesion: flexible electrode flaps that act like a thumb-index gripper. "This is the first time that electroadhesion and soft robotics have been combined together to grasp objects," says Jun Shintake, doctoral student at EPFL. The lightweight gripper may soon be handling food for the food industry, capturing debris in outer space, or incorporated into prosthetic hands. When the voltage is turned on, the electrodes bend towards the object to be picked up, imitating muscle function. The tip of the electrodes act like fingertips that gently conform to the shape of the object, gripping onto it with electrostatic forces in the same way that the balloon sticks to the wall. These electrodes can carry 80 times its own weight and no prior knowledge about the object's shape is necessary. In comparison, other soft grippers are either pneumatically controlled or fail at picking up fragile objects without telling the gripper beforehand about the object's shape. They also have been unable able to handle flat or deformable objects.