Building machines that replicate the delicate touch of a human hand is a complex undertaking that has seen the development of all kinds of soft robotic grippers, fromsquishy green blobs to boa constrictor-inspired claws. Scientists are now claiming an important advance in this area, demonstrating a robotic device that can better grasp fragile objects through the help of electroadhesion, the very same phenomenon that sees balloons cling to ceilings after being rubbed on your hair.
Led by Jun Shintake, a doctoral student at Swiss research institute EPFL, the scientists set out to develop a soft gripper that would act much like the thumb and index finger on a human hand. They designed flaps consisting of five layers: a pre-stretched elastomer in the middle with two layers of electrodes on either side, and then two layers of silicone on the outer.
In its normal state, these flaps curl outwards. But when an electrical current is delivered the attraction between the electrodes draws them together in an action the researchers say mimics muscle flexion. But the real clincher for this type of robotic gripper is its electrostatic field, made possible by the interlocking electrodes at the tips of the flaps.
When it came to testing out the device, the researchers were able to use it to pick up fragile items such as an egg, water balloon or paper. One of the claimed advantages over other soft grippers is its ability to handle delicate objects with no prior knowledge of their shape. Rather, the flaps gently conform to the surface, with the electroadhesive affect assisting it in carrying items 80 times its own weight.
While the researchers say this is the first time electroadhesion has been combined with soft robotics, a startup called Grabit has actually been serving electroadhesive grippers to customers for warehouse automation and package handling since 2013, and evenexperimenting with drone delivery.
Describing their version as lightweight and scaleable, however, the EPFL researchers have high hopes for their gripper, claiming the design could one day see them used in missions to collect space debris, food handling applications and advanced prosthetic hands.
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