The Art of Folding: Exploring the Science of Origami

Researchers at Harvard have been experimenting with using an origami technique called snapology, which is a way of connecting multiple sheets of folded material into geometric shapes. This technique is similar to the map-folding Miura-orifold being used with solar panels, but instead of a single sheet, several layers are stacked together. In March 2016, they built a cube-shaped robot out of smaller cubes to demonstrate the concept. Using pressurized gas, the researchers could manipulate each fold in the whole block of cubes independently, which allowed them to expand and collapse the robot into all kinds of different shapes and sizes - including completely flat.

The same technique could eventually be used to fold and construct structural materials - to make temporary shelters, for example. So far, we've talked about things that use motors, magnetism, and air pressure to fold, but the award for creativity in folding mechanisms should probably go to a group of researchers at North Carolina State University. In a paper published in March of this year in the journal Science Advances, the team announced that they'd figured out a way to make folds in a specific order by using colored lights.

They printed different types of colored lines on a white sheet of plastic, then shined different colors of bright light on the plastic. The light is reflected by most of the white plastic, but it's absorbed along those colored lines. A red line, for example, will absorb colors that aren't red, and a black line will absorb all the colors. When a line absorbs light, it gets warmer, which makes the colored plastic contract, turning the line into a hinge. These hinges are printed in specific colors, so you can make the plastic fold in different ways by shining different colors of light on it.

Extra-complicated folding patterns often need to be folded in a specific order, so scientists could use this system to design all kinds of new shapes and functions. Another advantage of origami is that paper is cheap - making it especially useful for work in remote areas where people might need lightweight and biodegradable instruments. So a team of researchers at Binghamton University in New York has been developing folding paper batteries, powered by bacteria.

And in 2016, they came up with a way to make them out of a single sheet of paper. This type of battery is called a microbial fuel cell, and it works because as the bacteria turn food into energy, most bacteria move electrons through a series of chemical reactions called the electron transport chain. At the end of this process, they eject an electron, which is usually absorbed by an oxygen molecule. But if you remove the oxygen by drawing the bacteria into the center of the battery, that electron can be captured by something else - like one of the battery's electrodes.

So the paper's designed to fold in a way that keeps the bacteria isolated, and separates the battery's electrodes. It only provides a few microwatts of electricity, but even that tiny amount could be used for small-scale experiments or medical tests in places that don't have access to electricity. Almost any drop of dirty water could power this battery, since it works with most bacteria. And since paper is biodegradable, it's also easier to dispose of than traditional batteries.

Other kinds of paper equipment are being developed too. In 2016, a team from Stanford built a paper centrifuge inspired by those whirligig toys, where you pull a string to spin a small disk really fast. Centrifuges also work by spinning really fast, which lets them use centripetal force to separate things with different densities. One of their most useful applications is separating plasma from blood - a crucial step for a lot of blood tests.

A typical laboratory centrifuge costs $700 and weighs more than 2 kilograms, which means that a lot of people in developing countries, especially in remote areas, don't have access to one. But this paper centrifuge costs only 70 cents and weighs just 2 grams, and it gets similar results. The team showed that it can be used to diagnose conditions like malaria and sleeping sickness, and the next step is to do some testing to actually test it in a clinical setting.

From outer space to your stomach, things that fold, compress, and expand are becoming an important part of the future of science. And who knows? Maybe someday you'll have to take an origami class as part of your engineering degree. Thanks for watching this episode of SciShow, which was brought to you by our patrons on Patreon. If you want to help support this show, you can go to patron.com/scishow. It's like a subscription, but you're paying. But you can also just subscribe and we appreciate that as well. And you can do that at youtube.com/scishow

"WEBVTTKind: captionsLanguage: enIf you’ve ever made a cootie catcher orpaper airplane, then you know how useful foldingcan be as a construction technique, especiallyif you’re trying to annoy your grade schoolteachers.But say the only thing you can make out oforigami is a rock.Before you practice your free-throw on therecycle bin, take a closer look.That paper rock has all kinds of interestingphysical properties.For one thing, it’s very strong.You can only compress standard printer paperby hand to a point where about 90% of it isstill air.It’s also a little springy, which is whycrumpled paper is such a great packaging material.The ball’s strength comes from flat sectionsof the paper that are layered together toform thick walls.Those walls are supported by stiff ridgesthat brace the ball in different directions.And that’s just what you can get from foldingrandomly.With careful planning, you can do way more,like transport bulky things in small packagesand easily change something’s shape.That’s led to a deluge of recent researchinto things that fold, collapse, or expand.All inspired by origami.With folding, you can compress bulky objectsinto a small space without sacrificing toomuch structural integrity.That makes it great for transporting thingsto places that are hard to get to, like thesites of natural disasters, outer space, oreven the inside of the human body.Natural disasters can damage infrastructurelike roads and bridges at a time when they’reneeded most.Victims can be isolated from emergency aidwhen every minute counts.With that in mind, in 2015, a team of researchersfrom Hiroshima University in Japan designedan emergency bridge that can fold small enoughto fit in a trailer.It's a type of truss bridge, the kind madefrom beams connected to form strong shapeslike triangles.If you ever made a bridge out of spaghettiand marshmallows, you made a truss bridge.This kind of bridge takes advantage of theprinciple that beams, like strands of spaghetti,perform well when they’re pulled or compressedalong their length, even though they’llbreak or deform if they’re bent.To prevent bending force on its beams, it’simportant that the connection points of atruss bridge work like pin joints, which rotatelike your knee — meaning that they can onlyswing back and forth along one path.Pin joints are used in truss bridges so thatif there’s a force pushing sideways on abeam, it’ll rotate around the joint insteadof bending in the middle.Normally, the beams in a truss bridge arearranged so that overall, the beams don’trotate too much and the bridge is stable.But this foldable bridge is designed so thatall the pin joints are free to rotate whenthe bridge is being folded or unfolded.Once you lock the base of the bridge in place,you end up with triangles along the sidesof the bridge that constrain the rotationof the pin joints.That’s how you end up with a stable, strongbridge ready for traffic.Within an hour, this bridge can be expandedto more than 20 meters and easily hold theweight of a moving car.And since the bridge just unfolds into place,practically anyone can build it safely.No complicated assembly required.NASA also needs things that can fold up, thenexpand — like solar panels and antennasthat are compact while they’re launched,but big and sturdy once they get out intospace.A perfect job for origami.Folding solar panels have been around fora while, but newer, more advanced materialsare being used to make thinner panels.And with thinner panels, engineers are hopingto use all kinds of new folding techniquesto fold the panels up even smaller.Some of these folds, like the Miura-ori fold,have already had their first tests in space.This fold uses alternating mountain and valleyfolds in a pattern that lets you open an entiresheet of paper by only pulling on two corners.And the search for better folds is still going.In 2014, engineers from NASA’s Jet PropulsionLaboratory worked with origami experts todesign prototypes for solar arrays that couldeasily unfold from compact cylinders intolarge flat disks.The cylinder would basically wrap around aspacecraft like a skirt, and use the spacecraft’srotation to unfold.Folding techniques can also help you get thingsinto spaces as cramped as the inside of yourbody.And in May 2016, researchers at MIT’s ComputerScience and Artificial Intelligence Laboratorydemonstrated a prototype robot that couldbe folded into a capsule, swallowed, and unfoldinside your stomach.It would mainly be used to dislodge foreignobjects from the stomach wall — say, ifa kid swallows a button battery.Batteries can burn a hole through tissue ifyou leave them there, so the robot could helpdoctors avoid risky surgery.The robot’s body is made of a folded-upsheet of pig intestine to protect it fromthe stomach’s acidic environment, with amagnet embedded in it.The researchers can manipulate magnetic fieldsoutside the body to move the robot along thewalls of the stomach.So far, they’ve demonstrated that theirrobot can safely remove objects from a pigstomach, and they want to test it on liveanimals next.And eventually, they’re hoping to redesignthe robot so it can move around without thoseoutside magnetic fields.Origami’s being used in other new robots,too.Researchers at Harvard have been experimentingwith using an origami technique called snapology,which is a way of connecting a bunch of sheetsof folded material into geometric shapes.The technique is similar the map-folding Miura-orifold being used with those solar panels Italked about earlier, but instead of a singlesheet, several layers are stacked together.In March 2016, they built a cube-shaped robotout of smaller cubes to demonstrate the concept.Using pressurized gas, the researchers couldmanipulate each fold in the whole block ofcubes independently, which allowed them toexpand and collapse the robot into all kindsof different shapes and sizes — includingcompletely flat.And the same technique could eventually beused to fold and construct structural materials— to make temporary shelters, for example.So far, we’ve talked about things that usemotors, magnetism, and air pressure to fold.But the award for creativity in folding mechanismsshould probably go to a group of researchersat North Carolina State University.In a paper published in March of this yearin the journal Science Advances, the teamannounced that they’d figured out a wayto make folds in a specific order by usingcolored lights.They printed different types of colored lineson a white sheet of plastic, then shined differentcolors of bright light on the plastic.The light is reflected by most of the whiteplastic, but it’s absorbed along those coloredlines.A red line, for example, will absorb colorsthat aren’t red, and a black line will absorball the colors.When a line absorbs light, it gets warmer,which makes the colored plastic contract,turning the line into a hinge.These hinges are printed in specific colors,so you can make the plastic fold in differentways by shining different colors of lighton it.Extra-complicated folding patterns often needto be folded in a specific order, so scientistscould use this system to design all kindsof new shapes and functions.Another advantage of origami is that paperis cheap.That makes it especially useful for work inremote areas where people might need lightweightand biodegradable instruments.So a team of researchers at Binghamton Universityin New York has been developing folding paperbatteries, powered by bacteria.And in 2016, they came up with a way to makethem out of a single sheet of paper.This type of battery is called a microbialfuel cell, and it works because as they turnfood into energy, most bacteria move electronsthrough a series of chemical reactions calledthe electron transport chain.At the end of this process, they eject anelectron, which is usually absorbed by anoxygen molecule.But if you remove the oxygen by drawing thebacteria into the center of the battery, thatelectron can be captured by something else... like one of the battery’s electrodes.So the paper’s designed to fold in a waythat keeps the bacteria isolated, and separatesthe battery’s electrodes.It only provides a few microwatts of electricity,but even that tiny amount could be used forsmall-scale experiments or medical tests inplaces that don’t have access to electricity.Almost any drop of dirty water could powerthis battery, since it works with most bacteria.And since paper is biodegradable, it’s alsoeasier to dispose of than traditional batteries.Other kinds of paper equipment are being developed,too.In 2016, a team from Stanford built a papercentrifuge inspired by those whirligig toys,where you pull a string to spin a small diskreally fast.Centrifuges also work by spinning really fast,which lets them use centripetal force to separatethings with different densities.One of their most useful applications is separatingplasma from blood — a crucial step for alot of of blood tests.A typical laboratory centrifuge costs $700and weighs more than 2 kilograms, which meansa lot of people in developing countries, especiallyin remote areas, don’t have access to one.But this paper centrifuge costs only 70 centsand weighs just 2 grams, and it gets similarresults.The team showed that it can be used to diagnoseconditions like malaria and sleeping sickness,and the next step is to do some testing toactually test it in a clinical setting.So from outer space to your stomach, thingsthat fold, compress, and expand are becomingan important part of the future of science.And who knows?Maybe someday you’ll have to take an origamiclass as part of your engineering degree.Thanks for watching this episode of SciShow,which was brought to you by our patrons onPatreon.If you want to help support this show, youcan go to patreon.com/scishow.It's like a subscription, but you're paying.But you can also just subscribe and we appreciate that as well.And you can do that at youtube.com/scishow\n"