Gecko-inspired adhesives help soft robotic fingers get better grip

Scientists have developed a robotic gripper that combines the adhesive properties of gecko toes and the adaptability of air-powered soft robots to grasp a wide variety of objects.

The gripper can lift up to 20 kilogrammes of weight and could be used to grasp objects in a wide range of settings, from factory floors to the International Space Station (ISS), according to researchers at the University of California San Diego in the US.

Geckos are known as nature's best climbers because of a sophisticated gripping mechanism on their toes.

In previous work, researchers at Stanford University and NASA's Jet Propulsion Laboratory in the US recreated that mechanism with a synthetic material called a gecko-inspired adhesive.

This material was used primarily on flat surfaces like walls.

"We realised that these two components, soft robotics and gecko adhesives, complement each other really well," said Paul Glick, a PhD student at UC San Diego.

The team coated the fingers of a soft robotic gripper with the gecko adhesive, allowing it to get a firmer grasp on a wide range of objects, including pipes and mugs, while still being able to handle rough objects like rocks.

The gripper can also grasp objects in various positions, for example gripping a mug at many different angles.

Researchers demonstrated that the gripper could grasp and manipulate rough, porous and dirty objects, such as volcanic rocks - a task that is typically challenging for gecko adhesives.

It also was able to pick up pieces of large, cylindrical pipe - a task typically difficult for soft robotic grippers.

Since gecko adhesives are powered by molecular interactions between surfaces, they work best when they have a large contact surface area, researchers said.

Coating the inside of the soft robotic fingers with these adhesives maximises the amount of surface area they make contact with, ensuring a better grip, they said.