Researchers from the University of Cambridge says that humans would need large adhesive pads that covers about 40 percent of their body surface to be able to scale walls like Spider-Man. The research team also says that geckos are currently the largest animals to achieve the gravity-defying feats, crushing anyone’s hope of becoming a real Spider-Man.
The new study, published in the journal PNAS, proves that the total percentage of the body surface needed to be covered by adhesive footpads increases as the body size increases. This means that climbing walls is limited to smaller animals, as bigger animals would inconveniently need big feet.
The researchers said that humans need adhesive pads covering 40 percent of the total body surface or roughly covers 80 percent of their front. Researcher David Labonte from the university’s Department of Zoology said that the size of these pads would make the trait impractical. A shoe must be a European size 145 or US size 114 for a person to do the feats Spider-Man does.
Plus, the amount of body surface area per volume decreases as the animal’s size increases. For example, an ant has a lot of surface area but little volume while a blue whale does not have much surface area, but possesses mostly volume.
This may cause problems to bigger climbing species. These animals will need more sticking abilities to not fall off vertical or inverted surfaces but their body surface would be too little for the sticky footpads to help them do these things. The scientists suggest that the size limit for the adhesive pads would be about the size of a gecko.
“Our study emphasises the importance of scaling for animal adhesion, and scaling is also essential for improving the performance of adhesives over much larger areas,” Labonte asserted. “There is a lot of interesting work still to do looking into the strategies that animals have developed in order to maintain the ability to scale smooth walls, which would likely also have very useful applications in the development of large-scale, powerful yet controllable adhesives.”
According to the team, their findings may provide implications to the development of large-scale adhesives in relation to the size limits. However, bio-inspired adhesives currently work only on very small areas.