The gripping power of tree frog feet helped them solve the problem of getting a device to grip and hold wet, slippery tissue when the robot is inside a patient’s abdominal cavity. And, because of that gripping power, this prototype can easily move through the patient’s internal abdominal wall, giving surgeons unprecedented insight into what they’re doing through a real-time video stream.
From nature and its 3.8 billion years of evolution-which has created a kind of organic and free research and Development Department for the world-the patterns on the legs of the tree frog provided a way for the device to hold and release a grip without harming the patient.
According to the principal investigator of the project, Professor Anne Neville, of the Royal Academy of Engineering Chair in Emerging Technologies at the University of Leeds, tree frogs have hexagonal channels on their feet that upon contact with a wet surface build capillary bridges and therefore an adhesion force.
“It’s the same kind of idea as a beer glass glued to a beer mat, but the patterns build a large number of adhesion points that allow our robot to move on a very slippery surface when Upside Down,” adds Professor Neville. “To work effectively, this robot will have to move to all areas of the abdominal wall, rotate and stop under control, and remain stable enough to take good quality images for surgeons to work with.”
The tree frog-inspired robot has four feet, each can hold a maximum of about 15 grams per square centimeter in contact with a slippery surface. The researchers finally want to create a robot that is 20×20×20 mm so that it can easily fit through the incisions made during keyhole surgery. The current prototype weighs 20g (which is about the weight of 20 coins or 20 clips) and researchers say it can also be reduced. The study was funded by a £450,000 grant from the new and emerging technology applications fund (NEAT).