Researchers from the University of Bristol have developed stretchable, multi-layer, skin-like robots that can be rolled up and inserted into your pocket. The robots, known as ElectroSkin robots, contain dielectric elastomer actuators (DEAs) and soft electroadhesives (EAs). Led by Professor of Robotics Jonathon Rossiter, the researchers published their paper in the journal of Soft Robotics. This new study could allow scientists to develop thin and light-weight robots that could be deployed in dangerous environments and could be used on robot grippers for delicate objects and wearable technology in the future.
A diagram of the ElectroSkin robot showing areas powered for actuation and electroadhesion. (Image Credit: University of Bristol)
The dielectric elastomer actuators are made of deformable dielectric membranes inserted between two electrodes that are made of conductive silicone. This forms parallel capacitors that can be deformed by applying an electric field due to Maxwell pressure.
The soft electroadhesives contain planar electrodes embedded in a soft dielectric. This allows them to act like coplanar capacitors that create controllable adhesion through a voltage. When an electric field is applied between the electrodes, it causes polarization in direct contact with an object and generates electrostatic attraction forces.
While ordinary robots are rigid and noncompliant, soft robots are compliant and flexible, stretching and twisting to adapt to their environment. With new discoveries, researchers have made it possible for soft robots to separate their mobility from their capabilities to grip surfaces they can traverse on. Diving into the biological world, the team found inspiration from slimy slugs and snails to develop the ElectroSkin robot, which can climb walls by alternately contracting embedded artificial muscles and gripping onto surfaces via electrical charges.
To test out the concept, the researchers built a soft self-actuating conveyer belt that can transport small items. Due to active areas being exposed as electromechanical actuators or as electrostatic gripper elements, or both at the same time, ElectroSkin robots can be propelled in different modes and in the future, the robots will be able to climb up walls, crawl across ceilings, and explore dangerous areas, including collapsed buildings.
The team also experimented on an untethered ElectroSkin conveyer, based on a mini microprocessor, lithium polymer battery, and two small high-voltage amplifiers. Their next objective is to integrate stretchable triboelectric nanogenerators to develop self-powered ElectroSkin robots.
"ElectroSkin is an important step toward soft robots that can be easily transported, deployed and even worn," says Professor Jonathan Rossiter. "The combination of electrical artificial muscles and electrical gripping replicated the movements of animals like slugs and snails, and where they can go, so could our robots!"
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