One particularly active area of robotics research involves the exploration of soft parts. Be they legs, artificial muscles or the grippers used to grasp objects, these more malleable components are opening up new possibilities and making machines safer for humans to work around. Now they're gaining a helping hand from the amazing adhesive properties of the gecko, combining to form robotic fingers that punch well above their weight.

Adhesives that can be switched on and off, grippers that latch onto space debris and anchors that can be used by astronauts working outside the International Space Station are just a few potential technologies to be inspired by the gecko. These clever creatures use millions of microscopic hairs on their feet and legs to bind to surfaces at a molecular level, affording them their incredible grip.

Researchers at Stanford University, University of California, San Diego (UCSD) and NASA's Jet Propulsion Laboratory (JPL) have now used photolithography to develop a synthetic material that mimics the natural gripping abilities of the gecko and can be used to coat the fingers of a soft robotic gripper.

The 3D-printed system makes use of stretchable silicone embedded with a high-strength fabric in the finger, which allows it to bend, but not stretch out of shape when dealing with heavier loads. The fingers, meanwhile, are firmly fixed to a base, making for a mix of soft and stiff materials that allows the gripper to both conform to differently shaped objects and endure large forces.

And because the gecko-inspired molecular reactions occur more effectively on larger surface areas, the material's properties are a particularly effective coating for soft robotic grippers that conform to differently shaped objects, as it means there is a greater surface area to work with.

By developing control algorithms that allow the robot to distribute the right amount of force along the entire length of its fingers, the team ended up with a gripper that can lift various objects, in various positions, weighing up to 45 lb (20 kg). This includes rough, porous objects like volcanic rocks, smoother objects like cylindrical pipes, and everyday things like coffee mugs and tomatoes.

"We realized that these two components, soft robotics and gecko adhesives, complement each other really well," said Paul Glick, the paper's first author and PhD student in the Bioinspired Robotics and Design Lab at UCSD.

From here, Glick and his colleagues plan to further develop algorithms that really take advantage of the adhesives, while also exploring the potential for the gripper to be used in zero-gravity environments and space operations.

You can see the gecko-inspired robotic gripper in the video below, while the research was published in the journal IEEE Robotics and Automation Letters.

Source: UCSD

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