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In mid-January, scientists from University of Cambridge's Department of Zoology released some heart-breaking news for Spider-Man fans. The researchers said that the web-slinging hero could never exist in real-life. And it is not due to the lack of radioactive spiders, but because humans are simply too big to skitter up tall buildings.
For the study which was led by Dr. David Labonte, the team recorded the weight and footpad size of 225 different climbing animals. These include mites, spiders, tree frogs, geckos, and even bats. What they discovered is that the proportion of sticky pads increases disproportionately with weight. For example mites, the smallest creatures tested, required about 200 times less viscous body-surface-area than the larger geckos. This they believe, limits the size of the climbing animals because at some point, the amount of sticky surface needed becomes impractical.
According to the Cambridge team's calculations, humans would need 40% of their total body surface or about 80% of the front covered with sticky pads before they would be able to climb walls. Though they could go the way of the gecko and put them all on their feet, the study's senior author Walter Federie, estimates that they would have to be the equivalent of US shoe size 114 (European 145).
These findings led the scientists who published their results in the Proceedings of the National Academy of Sciences on January 18, to conclude that "there is a size limit to sticky footpads as an evolutionary solution to climbing - and that turns out to be about the size of a gecko."
The researchers did state that the one way we could climb walls was by following the example of tree frogs. The smart amphibians have figured out how to increases the amount of 'glue' to compensate for the increased size. The means that the larger the frog, the stickier its footpad!
But researchers at California's Stanford University were not willing to kill the dreams of every Spider-Man fan. A few weeks after the Cambridge study was released they issued a rebuttal to the claims with findings of their own.
In a video published on YouTube on January 27, mechanical engineering student Elliot Hawkes said one can bypass the issue if, "You don’t just copy the gecko, but instead you are clever about how you distribute your weight." He suggests climbing a wall using a device like the Gecko Glove.
Created in 2014 by Hawkes as part of his dissertation or final year project, the Gecko Glove has 24 adhesive tiles that have been covered with tiny sawtooth-shaped polymer structures each measuring 100 micrometers in length. According to graduate student Eric Eason, who worked on the project with Hawkes, "When the pad first touches the surface, only the tips touch, so it's not sticky. But when the load is applied, and the wedges turn over and come into contact with the surface, that creates the adhesion force." With these ingenious gloves, anyone can attain Spider-Man-like wall scaling powers instantly.
The Stanford team says that the current prototype of the Gecko Glove can withstand up to 200 pounds. Even better, it has the potential to support up to 2000 pounds if the glove's size is increased! Though the Cambridge researchers have not issued a rebuttal yet, we have a feeling they are working on it - Stay tuned, for this argument is just getting interesting!