Researchers have developed a promising new adhesive that cleans itself after use without requiring water or chemicals, quite like the remarkable hairs found on the toes of the gecko, the common household lizard.
"It brings us closer to being able to build truly all-terrain robots, which will be able to scamper up walls and across ceilings in everyday environments rather than only on clean glass," said Ron Fearing, University of California (UC) Berkeley professor of electrical engineering and computer sciences.
Fearing, who is leading the research team, said: "We can envision robots being able to go anywhere they are needed, perhaps in the search for survivors after a disaster".
The development was reported online on Wednesday in Langmuir, a peer-reviewed journal of the American Chemical Society.
For years, scientists have been trying to develop a man-made version of the toe hairs that make the lizard's acrobatic feats possible. Earlier this year, Fearing's group developed another gecko-inspired adhesive using polymer microfibres that could easily attach to and detach from clean surfaces.
But researchers said replicating the gecko's ability to walk through dirty surfaces yet keep its feet clean enough to climb walls has been tricky.
In 2005, research led by Kellar Autumn, associate professor of biology at Lewis & Clark College in Portland, Oregon, and one of the leading experts in the US on gecko biomechanics, revealed how the gecko keeps its feet sticky but clean by shedding dirt particles with every step.
"It goes completely against our everyday experience with sticky tapes, which are 'magnets' for dirt and can't be reused," said Fearing. "With our gecko adhesive, we have been able to create the first material that is adhesive and yet cleans itself a little bit with every contact."
"This new material likes to adhere to surfaces, but it does not like to collect dirt particles," said Jongho Lee, UC Berkeley graduate student in mechanical engineering and co-author of the new study.