A team of researchers at Harvard University's Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a micro-robot that can climb vertically and upside down. The robot, named HAMR-E (Harvard Ambulatory Micro-Robot with Electroadhesion) uses specialized electroadhesive foot pads and origami ankle joints to walk over conductive surfaces such as the inside walls of a commercial jet engine. The team's research has recently been published in Science Robotics.
From the Wyss Institute article: "The team based HAMR-E on one of its existing micro-robots, HAMR, whose four legs enable it to walk on flat surfaces and swim through water. While the basic design of HAMR-E is similar to HAMR, the scientists had to solve a series of challenges to get HAMR-E to successfully stick to and traverse the vertical, inverted, and curved surfaces that it would encounter in a jet engine.
First, they needed to create adhesive foot pads that would keep the robot attached to the surface even when upside-down, but also release to allow the robot to “walk” by lifting and placing its feet. The pads consist of a polyimide-insulated copper electrode, which enables the generation of electrostatic forces between the pads and the underlying conductive surface. The foot pads can be easily released and re-engaged by switching the electric field on and off, which operates at a voltage similar to that required to move the robot’s legs, thus requiring very little additional power. The electroadhesive foot pads can generate shear forces of 5.56 grams and normal forces of 6.20 grams – more than enough to keep the 1.48-gram robot from sliding down or falling off its climbing surface. In addition to providing high adhesive forces, the pads were designed to be able to flex, thus allowing the robot to climb on curved or uneven surfaces."
“This iteration of HAMR-E is the first and most convincing step towards showing that this approach to a centimeter-scale climbing robot is possible, and that such robots could in the future be used to explore any sort of infrastructure, including buildings, pipes, engines, generators, and more,” said corresponding author Robert Wood, Ph.D., who is a Founding Core Faculty member of the Wyss Institute as well as the Charles River Professor of Engineering and Applied Sciences at SEAS.
Read more about the sticky footed robot that climbs walls and ceilings at Wyss Institute.