The Lizard That Uses Nanotechnology to Walk Upside Down

hey smart people joe here and this is vanilla bean vanilla bean is a gecko now i've always wanted to do this okay little buddy time to do your thing no pressure just like the whole world watching look at that gekkos have this incredible ability to stick to just about any surface i mean hanging upside down from glass walking up walls i mean it's amazing they can cling tight enough to do this yet let go with almost no effort and they can do this again and again and again and their grip never wears out take a look at their feet though it's not exactly obvious how they do this well today we're going to investigate that and we're going to get really up close and personal with this guy or gal's feet i i can't tell which and we are going to figure out how they use physics to create that extreme grip and how it's inspiring scientists to create new materials with incredible gripping properties that are inspired by nature all right stick around get [Music] walking up walls would be awesome i mean think about it i could be like a secret agent or a jewel thief or a superhero unfortunately it's a little bit harder than it looks but geckos can do that of course they've had hundreds of millions of years to perfect their skills of the 1500 or so gekko species on earth about 60 percent can wall walk and people have been amazed by this for thousands of years i mean maybe you've heard of a guy named aristotle well he was like the smartest guy alive during his time and even he was stumped by what a gecko can do take a look at their feet we used to think the secret was those deep ridges here on their toes kind of makes you think of our fingerprints right they don't secrete anything sticky like snails or tree frogs well maybe geckos push down on those ridges to create suction like an octopus or something or maybe like insects they use them like microscopic fingers to grab onto a surface well the answer is cooler than any of those so here's the thing geckos can even cling to surfaces that are completely smooth and we're talking smooth down to the molecular scale to figure out what's going on we're going to need to look closer these images were created using an electron microscope and they show us that a gecko toe pad is covered in about half a million tiny hairs called siti zoom in even closer and each of those hairs is covered with hundreds of tiny little bristles that kind of look like spatulas those tiny little bristles they let a gecko's toes make contact with the surface it's climbing on on the nano scale we're talking billionths of a meter and when you think about climbing you think about things like i don't know friction and gravity but on the nano scale different forces take over than what we're used to and this is where it gets awesome a gecko can climb because the molecules in their feet are directly interacting with the molecules of what they're climbing on that leads to a special kind of attractive force called van der waals force now you might say that's what lets gekkos climb their walls you're never gonna laugh at my jokes okay so what does that mean so we're used to two oppositely charged things or things with opposite polarity attracting like the ends of a magnet well a gecko's feet aren't charged and the surfaces that they walk on aren't charged but they're able to use the same principle of attraction thanks to a very strange phenomenon down on the atomic scale the atoms that make up the surface and the atoms in a gecko's foot have positive nuclei and negative electrons usually those all cancel out because an atom with the same number of electrons and protons is basically neutral but electrons are always moving around and every so often they can end up more on one side of the nucleus than the other just like planets in the solar system can be occasionally more on one side of the sun so that side becomes more electron dense and it gets a slight negative charge the other side has a slight positive charge this is called a dipole and if another atom comes close enough in that moment it can get a slight negative and positive imbalance too and those slight opposite charges stick i mean that's crazy tiny little changes to where electrons are can create a little sticky force between two atoms and if we put the gecko on a surface that can't contribute to van der waals forces like a non-stick pan or something well the gecko can't grip these van der waals forces are really weak and they only work at those tiny nanoscale distances but they can really add up holding this gecko on my hand that weight is somewhere around one newton or less of force pushing down but each of those microscopic bristles on its toes they provide less than one one millionth of a newton of attractive force but a gecko has over a billion of those toe bristles and added up that's enough force to hold many times their body weight just from the attraction between atoms now you're smart so i know what you're thinking if that attraction is so strong then how do they let go whenever they want to well a gecko has the ability to align all of those millions of microscopic hairs using muscles and tendons in their feet and maximize their grip sort of like how the muscles in my hand create tension on my fingers and help me palm this ball are you impressed remove that tension in my hand and by the way that was a kid's soccer ball i'm not some sort of weird giant the same way just changing the angle that their toe bristles touch the surface gekko's van der waals grip disappears in milliseconds now stickiness and grippiness is a big deal to scientists if you've ever tried to move and re-stick a post-it note more than a couple of times you know that one of the problems with any reusable sticky thing is that it eventually wears out but gecko feet never lose their grip no matter how many times they are stuck and unstuck now by studying how geckos grip onto surfaces on the nano scale engineers have created biologically inspired materials like this gecko inspired tape now this is covered in thousands of tiny little hairs a lot like the gecko's foot and that stiff backing it acts just like the muscles and tendons in the gecko foot there's no glue on this surface but it can grip things super tight i mean just watch this vanilla bean are you impressed this is all thanks to the molecular gripping between this surface and the glass on the scale of billionths of a meter and i can remove it over and over again and it will never lose that grippiness hi phil swift here for gecko feet it's like a post-it note developed by millions of years of evolution and natural selection geckos use some pretty amazing nanotechnology it makes you wonder if we could be like spider-man if we had hands or gloves like this well i hate to disappoint you but no you might remember this rule in biology where as an organism gets bigger our mass goes up by a power of three and our surface area only goes up by a power of two we would need most of our body covered in van der waals grippers just to hang on and that is why there's no 50 pound geckos around which i'm pretty thankful for because you are much cuter this size alright stay curious new show mascot i don't know i you're you're gonna get some new fans vanilla bean are you having a rough year you're not alone we're all trying to make sense of 2020 and that's why you should check out self-evident it's a new show hosted by our friends danielle bainbridge from origin of everything and ali matu from the psych show because who better than a historian and a therapist to help guide us through this very weird year link down in the description a little hard to film you when you're on the camera would be awesome you just licked your eyeball i can't i can't do the the words when you're licking your eyeballs so cutely on the camera you

Channel: It's Okay To Be Smart

Views: 218,839

Rating: 4.9731493 out of 5

Keywords: nanotechnology, gecko, science, pbs digital studios, pbs, joe hanson, it's okay to be smart, its okay to be smart, it's ok to be smart, its ok to be smart, nano, nanotech, technology, how nanotechnology works, nature, lizards, reptiles, animals, education, physics

Id: p6QmV1EbVnI

Length: 8min 55sec (535 seconds)

Published: Sat Oct 31 2020

Reddit Comments

[u/ResponsibleStress495]

That imressive