Most grown-ups are aware that Spiderman is not real, but now researchers have proved that he not only isn’t real, but is truly impossible due to the size of the sticky pads that would be required to enable him to walk up a wall. Scientists have been studying how animals are able to scale walls and have found that the heavier an animal is, the harder it is to carry that load vertically.
Spiderman would have to have adhesive pads covering 40 percent of his body surface in order to be able to walk up a wall.
David Labonte, one of the researchers, said in a news release that as animals increase in size, the amount of body surface area per volume actually decreases. For instance, an ant has a lot of surface area compared to its weight. A blue whale has a lot of volume compared to its surface area.
Larger animals thus need more sticking power to match the stickiness-per-pound requirements. The scientists say that a gecko is about the maximum size for an animal who can use its sticking powers to climb vertical or inverted surfaces.
The researchers believe that their insights may have lead to new possibilities for large-scale adhesives, such as the sticky pads that would allow Spiderman to really climb a wall. The study, published Monday in PNAS, reveals that climbing animals range in size from mites to geckos, with the percentage of body surface covered by adhesive footpads increasing as the creature increases in body size.
Mites use about 200 times less of their body surface area for sticky foot pads than geckos do. Humans would require 80 percent of the front of the body to be sticky in order to climb walls. To climb a wall the way a gecko does a human would need huge sticky feet, U.S. size 114, according to Walter Federle, senior author of the study who is from the Cambridge Department of Zoology.
One other possible solution to the wall-climbing problem is to make the adhesive stickier. Some animals, such as tree frogs, have evolved this way. Labonte says there is still a lot of interesting work that can still be done on animals with stickier adhesive. These strategies would possibly allow the “development of large-scale, powerful yet controllable adhesives.”
Until then, no Spiderman.