Tiny frog that sticks in the wet inspires robotic breakthrough at university

The prototype device is the newest in a growing stable of machines at the university that are merging technology with nature to create solutions to age-old problems.

Researchers have studied the way tree frogs stick to wet surfaces and incorporated the same principle into the tiny robot’s feet to enable it to be used in keyhole surgery.

Lead researcher Professor Anne Neville, Royal Academy of Engineering chair in Emerging Technologies at the University of Leeds, said: “Tree frogs have hexagonal patterned channels on their feet that when in contact with a wet surface build capillary bridges, and hence an adhesion force.

“It is the same kind of idea as a beer glass sticking to a beer mat, but the patterns build a large number of adhesion points that allow our robot to move around on a very slippery surface when it is upside down.

“To work effectively, this robot will have to move to all areas of the abdominal wall, turn and stop under control, and stay stable enough to take good quality images for the surgeons to work with.”

The robot has four feet – each capable of holding a maximum of about 15 grams for each square centimetre in contact with a slippery surface.

PhD researcher Alfonso Montellano-Lopez, who has worked on the design for the robot, says it is now hoped his creation can be miniaturised and used to move across the internal abdominal wall of a patient, carrying a camera and moving without damaging the surface.

He said: “I think it’s achievable, depending on the funding it receives. This is the first design but once we get it to the right size it can be controlled by a surgeon using a computer externally.”

The frog robot joins other robots designed at the university.

The other designs include an electric ‘mole’ which can to dig through disaster zones to help look for survivors and a giant robo-worm that mimics the nervous system of a real nematode worm.