Robotic Fingers Use 'Artificial Muscles' to Lift Eggs Without Breaking Them

robotics electroadhesion egg epfl prosthetics
The robotic fingers developed by EPFL scientists use electrostatic to grip fragile and hard-to-grasp objects, like eggs and paper. EPFL

Researchers have invented robotic grippers that mimic the muscle function of fingers, capable of picking up fragile objects of arbitrary shape and stiffness.

The breakthrough combines artificial muscles with electrostatic adhesion, or electroadhesion, and could be used to allow prosthetic hands to pick up hard-to-grasp objects like eggs or pieces of paper.

The robotic fingers were developed by scientists at Ecole Polytechnique Federale de Lausanne (EPFL) using stretchable electrodes and rubber. 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 balloons can be made to stick to walls by rubbing them against certain surfaces.

robotic finger egg prosthetics electrostatic EPFL
The soft robotic gripper, made out of rubber and stretchable electrodes, uses electrostatic stickiness called electroadhesion to pick up objects. EPFL

"This is the first time that electroadhesion and soft robotics have been combined together to grasp objects," said Jun Shintake, a PhD student at EPFL and lead author of the paper.

The soft robotics that Shintake refers to are an emerging field of robotic engineering that uses materials like silicon and rubber to create soft and flexible devices capable of behaving in a manner unlike traditional robots. Benefits over traditional robotics include resilience, cost effectiveness and manoeuvrability.

In comparison to Shintake's invention, other grippers are either pneumatically controlled or fail at picking up fragile objects without the object's shape and weight being pre-programmed into the robotic system. They have also been unable to handle flat or deformable objects.

"The novelty of our soft gripper is the ideal combination of two technologies: artificial muscles and electroadhesion," said PhD co-supervisor Dario Floreano of EPFL.

Fellow PhD supervisor Herbert Shea added: "Our unique configuration of electrodes and silicone membranes is what allows us to control the bending of the flaps and electrostatic grip."