Placeholder Image

字幕表 動画を再生する

  • This video was created in  partnership with Bill Gates,

  • inspired by his new bookHow  to Avoid a Climate Disaster.”

  • You can find out more about  how we can all work together

  • to avoid a climate disaster in the link below.

  • [♪ INTRO]

  • One of the basic human needs is shelter.

  • And over the short time humans have been on Earth,

  • we've come up with a lot of  different ways to shelter ourselves

  • from mud huts, to wooden buildings, to  the towering skyscrapers of many cities.

  • But many of those materials  aren't as strong as they could be.

  • And the ones that are can have  an outsized impact on our planet.

  • So now, architects and engineers are  turning to nature for inspiration

  • for more resilient materialsstuff  that improves on what we use now,

  • and that often minimizes the  impact we have on this planet.

  • From cement that acts like sweat glands  to glass that mimics fish scales, here are

  • some biology-inspired materials that could  transform the future of construction.

  • One major threat to buildings is fire.

  • When a fire sweeps through a structure,

  • it often means a lot of new  construction is on the way.

  • That often means more cement and steel

  • and making both of those involves  a lot of greenhouse gases.

  • Thankfully, there are all kinds of ways  to make a building safer in a fire.

  • In addition to fire alarmsextinguishers, and sprinklers,

  • you can add fireproof materials to  the building's support structure

  • to keep it from failing, as well as  to the walls, floors, and ceilings,

  • to keep fire from spreading.

  • But these are all passive methodsAnd because they're extra materials,

  • they add extra cost and take extra energy to make.

  • So it would be helpful if  there were materials that could

  • actively prevent fire damage, plus be supportive.

  • Well, researchers in China  may have invented just that,

  • using human sweat glands for inspiration.

  • In a paper published in 2019,  they shared their development of a

  • fire-retardant cement blendwhich stops fire from damaging

  • a building's structure sort of like  how sweat keeps human bodies cool.

  • The cement is a blend of three materials:  a set of compounds named APP-PER-EN,

  • some reinforcing fibers, and a concrete binder.

  • Under normal conditionsit does what you'd expect

  • it holds up the weight of a building.

  • But if there's a fire, it goes through four  stages to stop that fire in its tracks.

  • First, as temperatures rise between  100 and 160 degrees Celsius,

  • the reinforcing fibers and  the APP-PER-EN start to melt

  • kind of like how sweat glands make  sweat when you start to get warm.

  • When the temperature reaches  above 170 degrees Celsius,

  • micro-channels and cracks form.

  • Then, temperatures above 300 degrees  cause the APP-PER-EN to foam, filling the

  • micro-channels and cracks and formingfire insulation layer like sweat on skin.

  • And finally, as the insulating layer formsgases get released, including water vapor.

  • This mimics the cooling mechanism of sweat

  • how when sweat evaporates, it takes  some of the body heat with it.  

  • This insulating layer protects the  cement from falling under high heat

  • by taking on a honeycomb shape.

  • This adds strength while also  insulating against heat transfer

  • using the air trapped in the honeycombs.  I know! It sounds like science fiction!

  • Then, after a fire, you can remove the  honeycomb layer and repair the material

  • instead of having to replace the entire  cement structure, saving costs and resources.

  • Next, speaking of heat, humans have  been passively heating their homes

  • with sunlight for thousands of years.

  • But we couldn't control the release  of this heat until the 20th century.

  • Only then did we invent collectors like  thermal walls, which could absorb heat

  • from sunlight and slowly release it over  time, keeping us warm throughout the day.

  • The trouble is, most of these  collectors are made from rigid,

  • heavy materials, which means  their uses are limited.

  • So engineers are looking to polar bears as  inspiration for textile-like solar collectors,

  • which would be more efficient, lightweightand flexible than their predecessors.

  • Polar bears have white fur and black skin  that work together as a natural solar

  • collector and insulator, which helps them  stay warm in the extreme cold of the Arctic.

  • Their outer fur is actually  transparentit only looks white

  • because of the way it's structured.

  • That transparency allows the  sunlight to reach their dark skin,

  • which converts the sun's energy into warmth.

  • Another layer of dense underfur close  to their skin is spaced just right,

  • creating little pockets of air that  trap heat close to the bear's body.

  • In fact, they radiate so little heat that  they're almost invisible to infrared detectors.

  • The surface of their coats looks the  same temperature as their environment!

  • Inspired by this heat-trapping abilityresearchers based in Germany and Austria

  • shared a new type of solar  collector in a 2015 paper.

  • They imagine it being used as part of solar power,

  • but this general idea could  also help with buildings, too.

  • The collector has two layers of  transparent plastic and silicone

  • that let light pass through to the bottom layer.

  • These layers are positioned aroundcentimeter apart, trapping a layer of air

  • between them and minimizing heat  loss like a polar bear's underfur.

  • The bottom layer is black siliconewhich absorbs the sun's light

  • and converts it to heat.

  • And the warm air can be pumped out  by a fan and stored for later use.

  • Early tests show that this collector  is able to generate temperatures

  • of up to 150 degrees Celsius —  although right now that only works

  • when it's in direct sunlight.

  • Still, while those extreme temperatures  might be helpful for solar power,

  • that's also not the kind of  heat you'd need in a building.

  • So, this idea could really come in handy,

  • especially as textile-based  buildings become more mainstream.

  • These futuristic buildings are  constructed from lightweight materials

  • stretched over a frame or woven together,

  • and are making everything about  a building more sustainable,

  • including its design, materials, usage, and  even how it's recycled at the end of its life.

  • Adding a polar bear-inspired heating  system would make them even more versatile.

  • Buildings also need to stay  comfortable in hot weather, though

  • and traditional cooling systems  aren't always the most efficient way

  • of managing a building's temperature.

  • Also, heating and cooling  systems account for a lot of

  • the greenhouse gases we emit as a planet.

  • Architects in the U.S. may have  come up with a more efficient way

  • of regulating a building's temperature, though,

  • and once again they have drawn on  inspiration from the human body.

  • In 2011, they releasedprototype of a building exterior

  • modeled after a biological process  that's similar to a thermostat

  • if a thermostat could control  more than just temperature.

  • That process is called homeostasisand many organisms use it

  • to keep their bodies functioning  within pre-set limits,

  • like an ideal temperature range or fluid balance.

  • Basically, it allows things  to remain stable on the inside

  • even as conditions change on the outside.

  • The team designed a glass building facade

  • inspired by the way human  muscles maintain homeostasis,

  • by expanding and contracting to regulate  heat as they work inside our bodies.

  • Similarly, the facade helps regulate  the internal temperature of the building

  • by opening and closing itself.

  • The exterior of the building is  made up of two layers of glass,

  • and sandwiched between them  are swirling silver lines.

  • Those lines are made up of ribbons  of a special type of polymer

  • that can have an electric current applied to it.

  • It also has a silver coating that  distributes an electrical charge

  • across the entire surface.

  • When sunlight warms the silver coating,

  • the polymer expands and shades the building.

  • Then, when the building cools off, the polymer  contracts and allows more light inside.

  • That way, the building responds to changing  environmental conditions throughout

  • the day, helping manage energy use in  a more efficient and sustainable way.

  • Now, this tech might not be best for  places where you want extra sunlight

  • like, in the middle of a cold winter.

  • But for a lot of climates, it  could be a great step forward.

  • Next up: concrete.

  • Like we mentioned earlier, making concrete  is a major contributor to climate change,

  • but sometimes, it seems like there's  only so much you can do about that.

  • Like, if a building is  damaged during an earthquake

  • well, you're gonna have to build another one.

  • Some teams are looking into  concrete recipes or processes

  • that are overall better for the planetbut some are taking another route.

  • Like, researchers at Purdue University  are trying to strengthen concrete instead

  • by using cracks.

  • More specifically, in 2018, they  developed 3-D printed cement structures

  • inspired by the mantis shrimp.

  • Mantis shrimp hit their prey  with a club-like front claw

  • at an extremely high speedwhich generates a lot of force.

  • But even then, that claw does  not crumble under pressure,

  • thanks to the way the shell's  microscopic layers are arranged.

  • The layers are stacked in a spiral, each  layer slightly offset from the next.

  • When stressed, cracks form in the  microscopic layers, but the twisted structure

  • keeps the cracks from spreading  through the entire club.

  • Specifically, the spiral forces  the cracks to form parallel,

  • or side to side within a layer, instead  of perpendicularor top to bottom.

  • And every time a crack has to change direction,

  • it requires a lot of force to do so, which  causes it to lose some of its energy.

  • If a crack does spread top to bottom, the  next layer vibrates as the crack reaches it,

  • absorbing the energy from the crack, keeping  it from traveling into the next layer.

  • Ultimately, these tiny twisting cracks  stop the club from falling apart,

  • by preventing larger cracks from forming  that would compromise the structure.

  • Using this club for inspiration, the  researchers 3D printed a cement paste

  • that's laid out in a similar spiral design.

  • Poured cement is brittle and when stressed,

  • large cracks can form and  lead to catastrophic failure.

  • Not so with this 3D-printed materialHere, tiny cracks are stopped

  • so they don't spread throughout the  layers, just like with the mantis shrimp.

  • So the concrete is inherently stronger.

  • The goal is to eventually use this  type of material to build more

  • earthquake-resistant structuresAnd that means less wasted concrete!

  • Finally, windows. Windows can be an  incredibly important part of a building

  • on an aesthetic level. But since they're  so fragile, they're also the weakest.

  • Except, by mimicking an overlapping  pattern found in fish scales,

  • researchers may have found a way to  improve the strength of laminated glass,

  • while still preserving the  ability to see through it.

  • Laminated glass is created by sandwiching a soft,

  • polymer-based layer between  two layers of regular glass.

  • This keeps the glass together  if it breaks, making it safer.

  • But it is not strongeror at least  it wasn't until researchers in Canada

  • discovered a way to improve  the lamination process.

  • In a paper published in 2018,  they outlined their process

  • for strengthening glass with  a new lamination technique.

  • They started by coating two  sheets of glass with a flexible,

  • heat-resistant polymer film, and then etched  straight lines into the glass with a laser.

  • The polymer film holds the glass  together through the etching process.

  • Then, they laid the sheets of  glass on top of each other,

  • with another layer of flexible  polymer sandwiched between.

  • They also rotated the top sheet of  glass so the etched lines go in the

  • opposite directionknown  as cross-ply architecture

  • and that gives the glass added  strength and flexibility.

  • When this type of glass is stressed, the  cross-ply architecture and stretchy polymer

  • middle work together to help the glass  be stretchy and tough instead of brittle.

  • Testing revealed this glass to be  50 times tougher than regular glass,

  • while still maintaining its see-through qualities.

  • If this kind of glass spread, that would  mean stronger, safer windows that might

  • need to be replaced less oftenall  thanks to a pattern inspired by fish.

  • Nature has been around for a long timeand we're only beginning to tap into

  • the engineering insights you can get  from billions of years of evolution.

  • But with materials like these, we're  looking at a future of buildings

  • that are safer, more resilientand better for our planet.

  • When you think about things  contributing to climate change,

  • construction materials might  not be what comes to mind first.

  • But making things like cement, steel, and  plastic releases a lot of greenhouse gases.

  • And if you want to keep learning more  about how we can make those things better,

  • you can read Bill Gates's new book  “How to Avoid a Climate Disaster.”

  • It talks about manufacturing, but also food,

  • heating and cooling, transportation, and more.

  • If you're interested, you can find out more about

  • how we can all work together to avoid  a climate disaster in the link below.

  • [♪ OUTRO]

This video was created in  partnership with Bill Gates,

字幕と単語

動画の操作 ここで「動画」の調整と「字幕」の表示を設定することができます

B1 中級

5 Ways Biology Is Transforming Buildings

  • 7 2
    joey joey に公開 2021 年 06 月 13 日
動画の中の単語