Researchers have developed a method of making gecko-inspired adhesive materials that is more cost-effective than current methods. It could enable mass production and the spread of the versatile gripping strips to manufacturing and homes.
Polymers with “gecko adhesion” surfaces could be used to make versatile grippers to pick up very different objects, even on the same assembly line. With the exception of things like Teflon, the polymer can adhere to anything. This is an advantage in manufacturing because the gripper does not need to be prepared for specific surfaces to be lifted. Gecko-inspired adhesives can lift flat objects like boxes, then turn and lift curved objects.
Current grippers on assembly lines — such as clamps, magnets, and suction cups — can each lift limited ranges of objects. Grippers based on gecko-inspired surfaces, which are dry and contain no glue, could replace many grippers or just fill in capability gaps left by other gripping mechanisms.
The adhesion comes from protrusions a few hundred microns in size that often look like sections of short, floppy walls running parallel to each other across the material’s surface. Up to now, molding has produced these mesoscale walls by pouring ingredients onto a template, letting the mixture react and set to a flexible polymer, and then removing it from the mold. But the method is expensive and time-consuming. Also, there are issues with getting the gecko-like material to release from the template, which can disturb the quality of the attachment surface.
The new method formed those walls by pouring ingredients onto a smooth surface instead of a mold, letting the polymer partially set, then dipping rows of laboratory razor blades into it. The material set a little more around the blades, which were then drawn out, leaving behind micron-scale indentations surrounded by the desired walls.