London, Apr 28 (ANI): If you thought it was only Spiderman who could glide on any surface with no apparent gravitational pull, then it's time to get out of fiction and look closer to reality - scientists have created robots that can scale walls and hang off the ceiling just like geckos.
Metin Sitti and Ozgur Unver of Carnegie Mellon University in Pittsburgh, Pennsylvania, have claimed that their new robots - a sticky-tracked wall climber and a 16-legged ceiling walker - could tackle many jobs in the home including painting ceilings and clearing cobwebs.
The researchers said that the robots could also play a part in exploration, inspection, repair and even search and rescue.
Moving ahead of using suction for locomotion in previous wall and ceiling climbers, scientists have resorted to a "sticky" elastic polymer, or elastomer, that can adhere to a variety of surfaces, including wood, metal, glass and brick.
By using the elastomers, scientists are hoping to mimic the mechanism, which geckos use to climb walls and walk upside down- the millions of tiny hairs called setae on their toe pads, reports New Scientist.
The researchers showed that the geckos' setae do this by harnessing van der Waals forces- a weak electrostatic attraction which operates only at an intermolecular level.
Thus, Sitti has been experimenting with squishy elastomers to mimic the forces that geckos' setae use.
Both robots made by Sitti use sticky elastomers, though not in the form of hairs, to grip surfaces using van der Waals forces.
Their wall-climbing robot, called Tankbot, is a palm-sized, 60-gram machine with a tacky elastomer tank track on either side of it, and its trick is to keep its tracks in close contact with the surface whilst continuously "unpeeling" itself.
Tests showed that Tankbot could deftly scale walls and even carry small payloads. However, Sitti said that its "adhesion falls short for upside-down ceiling climbing."
So for scampering on ceilings, the researchers are working on another design with stronger adhesion- the FourBar robot- which has a four tough plastic bars that move parallel to one another driven by a motor.
Each bar has four tacky elastomer footpads, mounted in pairs on rockers. When the eight footpads on the interior bars are stuck to a surface, the outer bars unpeel their footpads and move forwards. When they are safely restuck, the inner bars unpeel and move forwards.
Although the robot moved 30 metres upside down in tests, the researchers observed one problem with both robots-their elastomers can clog with dirt and dust and lose their crucial tackiness.
Sitti hopes to overcome this on future bots by using his hairy gecko-like elastomers-ultrafine nanoscale hairs do not provide micro-scale dirt particles with enough contact - so they simply roll off.
The details on the robots will be presented at the annual International Robotics and Automation Conference (ICRA) in Kobe, Japan, in mid-May. (ANI)