Written by Beth Askham
Researchers have made sticky hand pads that let you climb walls like Spiderman.
Inspired by gecko feet, a research lab at Stanford University in America developed the climbing device. This technology recently allowed a person weighing 70 kilograms to climb a sheer glass wall. The team have also used the structure of gecko feet to design super-sticky tape and climbing robots called Stickybots.
To walk on walls and ceilings, geckos have hair-like fibres called setae on their feet that stick to surfaces. These fibres are tipped with hundreds of spatulas, so small they are on the nanoscale.
Borrowing from nature
Mimicking the gecko’s feet, there are tiny wedges of silicon polymer on the surface of the new climbing device. These wedges are made from similar stuff as some kitchen spatulas, but are about the same thickness as a human hair. They are not sticky when touched lightly to a surface. But when you place a load on them, such as your body, the wedges flatten out, pressing on to the surface and sticking.
These tiny wedges can be removed and repositioned by the climber many times and will stick to surfaces including glass, plastic, varnished wood and metals.
Practical pads
If you copied gecko feet exactly, a human would need giant sticky pads on their hands about the size of two tennis rackets. To make the hand pads smaller and dependable, the researchers tweaked the gecko’s sticky system. They made sure the climber’s weight is distributed evenly over the surface of each hand’s sticky pad.
To do this, each pad is divided up into postage stamp-sized tiles that all flatten and stick to the surface, even if that surface is uneven. An array of springs and flexible cords within the pad distributes the load evenly. This ensures that all of the tiles have the same maximum load. If they didn’t do this, one tile would become overloaded and fail, overloading its neighbours and causing a wave of failing tiles over the entire pad.
Could this technology mean we could climb buildings like Tom Cruise in Mission Impossible? Maybe, but as we are not built like geckos, keeping our climbs to small walls might be the best idea until the technology develops.
If you’re after more science news for kids, subscribe to Double Helix magazine!
Leave a Reply