A revolução de materiais e o futuro da produção
Vivemos a era de ouro dos novos materiais. Somente em novembro de 2015, os cientistas que trabalham nesta área informaram a imprensa sobre 100 descobertas significativas de materiais que prometem ajudar na resolução de problemas relacionados à saúde, transporte e energia. Mas quais destas descobertas têm potencial para mudar o mundo?
Enquanto você lê este artigo, cientistas em algum lugar do mundo estão estudando novas descobertas de materiais que poderão melhorar desde as pequenas inconveniências – a bateria do laptop, por exemplo -, até a forma como vamos diagnosticar doenças no futuro, através de nanomateriais. Aviões mais leves, impressoras 3D mais potentes, tudo agora é pensado e criado de forma a consumir menos energia, menos água e considerando a reciclagem destes materiais posteriormente.
Descubra no artigo publicado pelo The Economist quais são os principais avanços que as empresas que buscam mudanças radicais nas tecnologias estão tornando realidade.
TECHNOLOGY QUARTERLY
NEW MATERIALS FOR MANUFACTURING
“I DO not depend on figures at all,” said Thomas Edison. “I try an experiment and reason outthe result, somehow, by methods which I could not explain.” And so it was that by testing1,600 different materials, from coconut fibre to fishing line and even a hair from a colleague’sbeard, Edison finally found a particular type of bamboo which could be used, in carbonisedform, as the filament in the first proper incandescent light bulb. He demonstrated it on NewYear’s Eve 1879 at his laboratory in Menlo Park, New Jersey.
The details of all this painstaking trial and error filled more than 40,000 pages of Edison’snotebooks, but his solution was soon superseded. By the start of the 20th century filamentswere being made from tungsten, which burned brighter and lasted longer. For over 100 yearsthe world was illuminated by light bulbs with tungsten filaments, and the light bulb becamethe cartoonist’s fixed shorthand for innovation of all sorts.
Now light bulbs are being replaced by light-emitting diodes (LEDs), which are more efficient atturning electricity into light than filaments are, and far longer-lived. LEDs first appeared in the1960s as indicator lights on electrical equipment. Today they provide powerful illumination forbuildings, streets and cars. In poor parts of the world they are bringing light to people whohave never seen an old-fashioned bulb.
Both Edison’s light bulb and the LED are inventions of materials science, the process of turningmatter into new and useful forms. But in the years between them both the materials and thescience became much more complex. The semiconducting materials, such as germanium orsilicon, from which LEDs are made, often with the careful addition of atoms of some othersubstance, require a different approach from that at Menlo Park. The sort of light theyproduce is fine-tuned by microscopic structures and the details of those extra atoms. PaceEdison, this sort of thing depends on a lot of figures—not to mention quantum theory.
Producers are heading towards a world of bespoke manufacturing
The ability to understand the properties of materials at the tiniest scales not only lets peopledo old things better; it lets them do new things. In Edison’s day, using light to send messageswas the province of the Aldis lamps that flashed messages in morse code from ship to ship.
Laser diodes—semiconductor devices engineered to produce a much purer light thanLEDs—can flicker on and off in a controlled way billions of times a second. In an astoundingnumber of applications where information has to get from A to B—be those end points a DVDand a speaker, a bar code and a supermarket checkout or the two ends of a transatlantic fibreoptic cable—laser diodes are doing the work. For all its seeming abstraction, the virtual worldis built on very real, very well-understood materials.
The warp and weft of a new car
This is what some scientists describe as a “golden age” for materials. New, high-performingsubstances such as exotic alloys and superstrong composites are emerging; “smart” materialscan remember their shape, repair themselves or assemble themselves into components. Littlestructures that change the way something responds to light or sound can be used to turn amaterial into a “metamaterial” with very different properties. Advocates of nanotechnologytalk of building things atom by atom. The result is a flood of new substances and new ideas forways of using them to make old things better—and new things which have never been madebefore.
University materials departments are flourishing, spawning a vibrant entrepreneurial cultureand producing a spate of innovations (see box below). Many of these discoveries will fail toscale up from laboratory demonstration to commercial proposition. But some just mightchange the world, as light bulbs did.
“We are coming out of an age where we were blind”
Faster, higher, stronger
The understanding of the material world provided by a century of physics and chemistryaccounts for much of the ever-accelerating progress. But this is not a simple triumph of theory.
Instruments matter too. Machines such as electron microscopes, atomic-force microscopesand X-ray synchrotrons allow scientists to measure and probe materials in much greater detailthan has ever been possible before.
A project at the International Centre for Advanced Materials at the University of Manchestershows such advances in action. In one of its labs scientists are using secondary ion massspectrometry (SIMS) to study the way that hydrogen atoms—the smallest atoms thereare—diffuse into materials such as steel, a process that can cause tiny cracks. SIMS works bybombarding a sample with a beam of charged particles, which causes secondary particles to beejected from the surface. These are measured by an array of detectors to create an image witha resolution down to 50 nanometres (billionths of a metre). It does not just reveal thecrystalline structure of the metal—and any flaws in it—but also determines chemicalimpurities, such as the presence of hydrogen. “We can now do in an afternoon what we oncedid in months,” says Paul O’Brien, a professor at the university. The hope is that BP, the oilcompany which is sponsoring the centre, will get better steels for its offshore and processingwork as a result.
As well as having ever better instruments, the researchers are also benefiting from a massiveincrease in available computing power. This allows them to explore in detail the properties ofvirtual materials before deciding whether to try and make something out of them.
“We are coming out of an age where we were blind,” says Gerbrand Ceder, a battery expert atthe University of California, Berkeley. Together with Kristin Persson, of the Lawrence BerkeleyNational Laboratory, Mr Ceder founded the Materials Project, an open-access venture using acluster of supercomputers to compile the properties of all known and predicted compounds.
The idea is that, instead of setting out to find a substance with the desired properties for aparticular job, researchers will soon be able to define the properties they require and theircomputers will provide them with a list of suitable candidates.
Their starting point is that all materials are made of atoms. How each atom behaves dependson which chemical element it belongs to. The elements all have distinct chemical propertiesthat depend on the structure of the clouds of electrons that make up the outer layers of theiratoms. Sometimes an atom will pair off one of its electron with an electron from aneighbouring atom to form a “chemical bond”. These are the kind of connections that givestructure to molecules and to some sorts of crystalline material, such as semiconductors.
Other sorts of atom like to share their electrons more widely. In a metal the atoms share lotsof electrons; there are no bonds (which makes metals malleable) and electric currents can runfree.
When it comes to making chemical bonds, one element, carbon, is in a league of its own; amore or less infinite number of distinct molecules can be made from it. Chemists call thesecarbon-based molecules organic, and have devoted a whole branch of their subject—inorganicchemistry—to ignoring them. Mr Ceder’s Materials Project sits in that inorganic domain. It hassimulated some 60,000 materials, and five years from now should reach 100,000. This willprovide what the people working on the project call the “materials genome”: a list of the basicproperties—conductivity, hardness, elasticity, ability to absorb other chemicals and so on—ofall the compounds anyone might think of. “In ten years someone doing materials design willhave all these numbers available to them, and information about how materials will interact,”says Mr Ceder. “Before, none of this really existed. It was all trial and error.”A walk through the labs of General Electric (GE)—the firm into which Edison’s trial-and-errorbased businesses were merged in 1892—shows similar approaches already in practice. MichaelIdelchik, the head of GE Research, points to new artificial garnets developed for use in bodyscanners. The scanners have to turn X-rays into visible light to create images, and the betterthey do so the lower the dose of X-rays the patient is exposed to. The company looked at150,000 subtly different types of crystal that scintillate when subjected to X-rays beforesettling on a specific type of garnet which, it hopes, will make scans much faster—safer andmore pleasant for the patient, more cost-effective for the hospital.
On top of the possibilities offered by single materials comes the potentially even richer worldof combining them. Elsewhere in Mr Idelchik’s empire work focuses on replacing nickel-alloyparts for jet engines with parts made from ceramic-matrix composites (CMCs). Their strongchemical bonds mean ceramics can endure more heat than metals; at the same time, and forrelated reasons, they are more brittle. A CMC that combines a metal with a ceramic—GE isusing silicon carbide—can get you the best of both worlds. The company hopes CMCs thatneed less cooling will mean more efficient engines that emit less carbon dioxide.
Computing power helps create such hybrids. It also helps designers understand how suchnovel materials can best be used. Many prototypes are now produced in virtual form longbefore a physical item is made, using software from companies such as Altair, a Michigan firm,Autodesk, a Californian one (see the “Brain scan” interview later in this report), and DassaultSystèmes, a French group. Engineers can model a chemicals plant, architects can “walk” clientsthrough a digital representation of a building, and cars can be virtually test-driven on differentroads and parked alongside rivals’ vehicles in street scenes.
All this greatly speeds up product development. The software is powerful enough to take theproperties of the materials used into account, allowing it to calculate things such as loads,stresses, fluid dynamics, aerodynamics, thermal conditions and much more.
Manufacturers are only just beginning to realise the potential this offers, says Jeff Kowalski,chief technology officer of Autodesk. Many firms simply adapt parts to use new materials,expecting to produce them with the same tools and processes as before. That gives“substandard results”, he reckons. It is when new materials are used to redefine productionprocesses and enable wholly new types of product that things get really innovative, andcartoonists get to draw light bulbs over people’s heads.
Just the thing
Business is heading towards a world of “generative design”, says Mr Kowalski: engineers willset out what they want to achieve and the computer will provide designs to fit that purpose.
As materials knowledge grows, computers will also find materials to meet the propertiesspecified by a designer. The properties of materials may even vary throughout their length andbreadth, because it is becoming easier to tinker with the microstructure. Some companies arealready well on their way to offering such Savile Row tailoring of materials.
Nanoparticles: To the heart of the matter
Engineering at the molecular level improves old materials as well as creating new onesNANOPARTICLES are often seen as a new, man-made invention, but they have long existed innature—salt from the sea and smoke from volcanoes can be found in the atmosphere in theform of nanoparticles. What interests materials scientists is that with modern processingtechniques it is possible to turn many bulk materials into nanoparticles—measured as 100nanometres (billionth of a metre) or less. The reason for doing so is that nanoparticles can takeon new or greatly enhanced properties because of quantum mechanics and other effects. Thisincludes unique physical, chemical, mechanical and optical characteristics which are related tothe particles’ size. Engineers can capture some of those properties by incorporatingnanoparticles into their materials.
Nanoparticles can take on new or greatly enhanced properties
Christina Lomasney, a physicist, is using nanoparticles to make nanolaminates, a completelynew class of material. She is the co-founder of Modumetal, a Seattle firm developing a type ofelectrolytic deposition. This works a bit like electroplating, in which a metal, usually in a saltform, is suspended in a liquid and deposits itself on a component when an electric current isapplied.
Modumetal has come up with a way to do this with great precision, using a variety of metals inthe liquid. By carefully manipulating the electric field, it builds up veneers of different metalsover a surface and controls how those layers interact with one another. “In effect, we grow amaterial, controlling its composition and microstructure,” says Ms Lomasney. The companyreckons it can do this at an industrial scale, cheaply and with conventional materials, such assteel, zinc and aluminium.
Its first products—various pumps, valves and fasteners—are treated with corrosion-resistantlayers that are more durable than conventional treatments, lasting up to eight times longer.
Some of them are already being used by oil and gas companies. Modumetal is now expandingproduction and, in time, plans not just to coat structures but actually grow them.
One of the more important applications for engineering the microstructure of materials is inbatteries. These have been made from various materials, such as lead-acid and nickelcadmium. Apart from being highly toxic, some of these ingredients are also bulky and heavy,hence mobile phones in the 1980s were brick-like. The rechargeable lithium-ion battery helpedslim them down.
Solid-state technology will offer about double the energy density
Scientists had been working on using lithium as a battery material for decades, because it islight and highly conductive. The difficult bit was shifting from the laboratory to large-scaleproduction. Lithium is inherently unstable, so instead of using the material in its metallic form,researchers turned to safer compounds containing lithium ions. In 1991 Sony successfullylaunched a commercial version of the lithium-ion battery, helping transform portableconsumer electronics.
Such batteries now power all manner of devices, not just smartphones and laptops but alsopower tools, electric cars and drones. Manufacturing faults and overcharging can cause themto overheat and even burst into flames, but after a series of early laptop-battery recalls and anumber of fires in cars and aircraft, manufacturers now seem to have got on top of theseproblems.
Yet the search for a better battery is still on. For some applications, such as electric cars, thiswould be transformative. Until recently the battery for an electric car could cost $400-$500per kilowatt hour, representing perhaps 30% or so of the overall cost of the vehicle, but costsare falling (see chart). In October General Motors said it expected the battery in its new ChevyBolt electric car, due to go on sale in 2016, to cost around $145 per kilowatt hour. The industrybelieves that once the cost comes down to around $100 per kilowatt hour, electric vehicles willbecome mainstream because they will be able to compete with petrol cars of all sizes withoutsubsidy.
Charge of the lithium brigadeSource: “Rapidly falling costs of battery packs for electricvehicles ” , by B. Nykvist and M. Nilsson, March 2015*Nissan and TeslaLithium-ion batterycosts, $ per kWh03001006009001,2001,500INDUSTRY “TAKE-OFF” POINT FOR ELECTRICCARS20060708091011121314All estimatesMarket leaders*
Getting there will require some clever materials science. Lithium-ion batteries are usuallymade as a laminated structure with a material called an electrolyte at their centre, typically aliquid or gel-like substance through which the lithium ions shuttle back and forth betweenelectrodes.
Tesla's bright idea
Lithium-ion batteries have been steadily getting better. Jeffrey “JB” Straubel, chief technologyofficer of Tesla, a Californian maker of electric cars, says that the battery cells for thecompany’s present Model S are made on equipment similar to that used a decade ago for thefirm’s first car, the Roadster. But with improved chemistry and production techniques, theenergy stored in them has increased by 50%. Tesla has teamed up with its Japanese batterysupplier, Panasonic, to build a $5 billion factory in Nevada that should push car-battery costslower. It will also make a new Tesla battery called Powerwall (pictured), which can be used tostore solar electricity generated at home.
Lay it on thin
Other companies are looking at a more radical change in the technology. One of them isSakti3, a Michigan startup, which is trying to commercialise a lithium-ion battery with a solidelectrolyte. Solid-state lithium batteries already exist, but mostly in the form of coin-sizedback-ups in electrical circuits. Scaling up production processes to make them big enough topower devices such as phones would be hideously expensive.
Sakti3, however, has found a way to make a solid lithium battery with a thin-film depositionprocess, a technique already widely used to produce things such as solar panels and flat-paneldisplay screens. “Solid-state technology will offer about double the energy density—that’sdouble the talk time on your phone; double the range in your electric car,” says Ann MarieSastry, the firm’s chief executive. The battery cells will also have a long service life and besafer, she adds.
So why has the technique not been used to make batteries before? The firm’s purported edgeis knowing what materials to use and how to make the process cost-effective. Everything,including the complicated physics, was worked out and extensively tested virtually before thecompany built a pilot production line. Ms Sastry explains that as the firm selected materialsand developed processes, the virtual computer tests enabled it to forecast the cost of scalingup production. When built in large volumes, the solid-state batteries should come in around$100 per kilowatt hour, and there is scope for further improvement.
Initially Sakti3 expects its solid-state cells to be used in consumer electronics, which seems allthe more likely since Dyson, a British maker of electrical appliances, bought the company for areported $90m in October. Dyson, which invented the bagless vacuum cleaner, is expandinginto domestic robotics, for which it reckons it needs good batteries. But with furtherengineering, the batteries might migrate to electric cars and grid storage too. A number ofresearch groups around the world are hoping for battery breakthroughs, including 24M, aMassachusetts startup, which is using nanotechnology to develop what it calls a cost-effective“semi-solid” lithium-ion battery.
“I think batteries will change the world,” says Mr Ceder at Berkeley, “and that is purely amaterials issue.” He has worked on nearly every battery technology, but lithium remains hisfavourite, not least because so much effort has been put into it. Once industry has invested alot in a particular technology, the sunk cost gives established materials a huge advantage. “Butthat doesn’t mean we won’t try to find new materials,” he adds.
There is a parallel here with silicon. This is not the best semiconductor, but it is readilyavailable, cheap and well understood, and an entire chipmaking industry has been built aroundit. What has driven the industry is Moore’s law: the doubling of computing power on a chipevery two years at no extra cost. Proposed in 1965 by Gordon Moore, one of Intel’s founders,the law has remained in operation ever since. But some think it is coming to an end as thefeatures packed onto a chip approach the size of atoms. At this scale, problems such as powerleakages and instability start to crop up. One day silicon may well make way for othermaterials that promise superior electrical properties, such as gallium arsenide, titaniumtrisulphide or possibly graphene.
Unclaimed treasure
Graphene is still looking for a killer app
Much hyped as a “wonder material”, graphene is a form of carbon discovered in 2004 atManchester University in Britain by Andre Geim and Kostya Novoselov, who won the Nobelprize in physics for their work. It is one of a number of two-dimensional materials, so calledbecause they are only an atom or so thick. Lots of researchers and startups have moved intographene because it is extremely light yet strong; it is transparent; and it can be made to workas a semiconductor. So far, though, most graphene is used in research labs, which are stilllooking for a “killer app”. Beside computer chips, potential uses might include membranes forwater purification, more efficient solar cells and invisible electrodes in glass. Meanwhile,though, carbon in other forms is already big business in two of the world’s largestmanufacturing industries.
Carbon fibre: Dark arts
Carbon-fibre composites are making light work of aeroplanes, and now cars tooTHE central building of BMW’s car factory in Leipzig is a strikingly modern structure by ZahaHadid, an architect renowned for her neo-futurist designs. The factory produces a variety ofvehicles, so it is no surprise to find a group of robots in one area, moving in perfect synchronyas they assemble body sections with a precision no human could hope to match. But the placeis unusually quiet, without any thundering metal-stamping machines or showers of weldingsparks. The clue to what is going on is the colour of the components. Instead of the usual silverof steel or aluminium, these parts are black. They are made from a composite material calledcarbon fibre.
Lighter aircraft burn less fuel and thus have lower emissions
This factory is different in other ways, too. “We do not weld; we have no rivets, no screws andno bolts. We just glue components together,” says Ulrich Kranz, the head of the division thatsince 2013 has been making BMW’s i3 and i8 electric and hybrid vehicles in Leipzig. Since thecarbon-fibre body provides the vehicle with its strength, the outer panels are mainlydecorative and made from plastic. These are simple to spray in a small paint booth, whereasmetal requires elaborate anti-corrosion treatment in a giant and costly paint shop. In all, the i3factory uses 50% less energy and 70% less water than a conventional facility.
The i-series are upmarket cars, but still produced in volume. BMW has succeeded in taking anew material hitherto used in low-volume specialist applications, such as aerospace anddefence, and turning it into something close to mass-produced. That called for radical changes.
When in 2007 the BMW board asked Mr Kranz to come up with an electric city car and a lowenergy production system, he and his team went into hiding to allow ideas to flow freely.
Mr Kranz’s material of choice was carbon fibre, not least to offset the weight of the battery.
The material is made from thin filaments of carbon woven into a cloth. This is cut and pressedinto the shape of a part and the fibres bound together with a plastic resin, cured by heat andpressure. The molecular structure of carbon compounds produces strong chemical bonds,much like those in diamonds, and by aligning the fibres at different angles the strength of acomponent can be reinforced exactly where needed.
The resulting structure, although stronger than steel, is at least 50% lighter, and also about30% lighter than aluminium. Nor does it corrode. But in the past the production process wasexpensive, slow and labour-intensive. That may not matter too much when making fighter jetsor Formula 1 racing cars. But even aircraft-makers had to speed things up and bring downcosts when they started making passenger jets from carbon fibre.
Look, few hands
These days carbon fibre makes up about half the weight of aircraft such as the Boeing 787Dreamliner or the Airbus A380 and A350. Lighter aircraft burn less fuel and thus have loweremissions. They can also carry more passengers and fly farther. There are economies inmanufacturing, too, because large sections of the aircraft can be made in one go instead ofhaving to join together lots of smaller aluminium panels. Aircraft-makers have found ways tospeed up some of the production process, but it is still too slow and expensive for high-volumecarmakers.
The answer that BMW came up was a different sort of factory and a new supply chain. Itbegins in Otake, Japan, with a joint venture between SGL group, another German company,and Mitsubishi Rayon. This produces what is called a precursor, a polyacrylonitrilethermoplastic, which looks a bit like fishing line wound onto large spools. This is shipped acrossthe Pacific to Moses Lake in Washington state, the site of another joint venture, this onebetween BMW and SGL. The location was chosen because it uses locally generated emissionfree hydroelectric power.
Black carpet
The precursor is passed through a series of heating stages in which it is carbonised intoblackened filaments only around 7 micrometres (millionths of a metre) in diameter. Some50,000 of these filaments are bundled together into a thicker strand and wound onto reels,much like a yarn in a textile factory. The tows, as the carbonised yarns are called, then crossthe Atlantic to another BMW-SGL joint venture, at Wackersdorf near Munich. Here they arewoven into sheets and layered into stacks that resemble carpets.
When the stacks arrive at the Leipzig factory, they are heated and pressed into a threedimensional “preform”. Various preforms are placed together to make up large structures,which together are pressed again, but this time resin is injected into the mould, bonding andcuring the final component inside the press tool. This usually happens within minutes, thoughin some aerospace factories the curing can take the best part of a day and requires apressurised oven called an autoclave. Robots move the parts around and glue them togetherto make the main body structure of the car. Further along the production line the body ismated to the drive module, which incorporates an aluminium chassis, electric motor, batteryand other components.
By the mid-2020s carbon fibre will be widely adopted in carmaking
Mr Kranz expects carbon fibre to be used more widely in cars, but thinks they will alwayscontain a mix of materials. BMW’s new 7 series executive car now has some carbon-fibre partsas well. Other carmakers are starting to use the material, and Apple, which has hinted that itplans to build an electric car, has reportedly been talking to BMW about carbon-fibreconstruction. Anthony Vicari, an analyst with Lux Research, a Boston consultancy, predicts thatby the mid-2020s carbon fibre will be widely adopted in carmaking.
Ready, steady, goCarbon fibre in the car industrySource:
Lucintel00.61.21.82.43.0020406080100FORECAST198085909520000510152025Productiontime per car ’000 hoursDemandlbs, m
But not without a battle. As in other industries, traditional materials are getting better, too.
Aluminium suppliers are developing new alloys. “Aluminium is the incumbent and these guysare pushing like hell or they will lose their entire industry,” notes Jean Botti, the chief technicalofficer of Airbus. Alcoa, a leading producer of aluminium, is developing a number oflightweight alloys. One of them, Micromill, is easier and faster to shape into intricate forms.
Ford has begun using it to replace some steel components in its F-150 pickups, one of its bestselling models in America.
The upshot is that manufacturers are being offered a wider choice of materials than they hadbefore, says Mr Botti. Carbon fibre has done wonders in aerospace, he reckons, but it is usedlargely in the bigger, long-range aircraft, of which only a handful might be built every month.
To increase the use of carbon fibre in smaller aircraft, aerospace firms have to speed upproduction and bring down costs further, but “there are new techniques we are thinking aboutwhich could tremendously reduce the cost of carbon fibre.” Airbus and Boeing both have plansto raise production of their workhorse short-haul aircraft, respectively the A320s and 737s, toan astonishing 60 or so a month to meet order backlogs. Still, he cautions, companies shouldalways take care to select the best material for a particular job. If Airbus were to replace theA320 with a new model, he says, he would have to look carefully to see if carbon fibreprovided the best value in a short-haul aircraft.
Airbus is also developing its own new materials. One of these is a proprietary aluminiummagnesium-scandium alloy called Scalmalloy. It is particularly good for making lightweighthigh-strength components. It is being commercialised by an Airbus subsidiary and is alreadyused in some racing cars. In powder form, Scalmalloy can also be employed in a revolutionaryform of manufacturing that is ideally suited to working with many new materials: additivemanufacturing, popularly known as 3D printing.
3D printing: Print me a pavilion
Additive manufacturing is a perfect way of using new materials
CARMAKERS can spend a year building a working prototype for a new car. Setting up machinesfor a production run of one is laborious and costly, since much of the work is done by hand.
But researchers in Tennessee have an automated system endearingly known as BAAM (BigArea Additive Manufacturing). Most people would call it a 3D printer, albeit a particularly largeone—and it is used to print cars.
The researchers work at the Oak Ridge National Laboratory, which is exploring a number ofadvanced manufacturing methods. BAAM was cobbled together from various bits of factory kitin partnership with Cincinnati Inc, a machine-tool company. In one experiment it made most ofthe body and chassis for an electric replica of a Shelby Cobra, a classic 1960s sports car. Theprinted parts that went into the vehicle were built up using a mixture of 80% polymer and 20%carbon fibre and weighed a mere 227kg. It took the team just six weeks to design, print andassemble the car.
A few companies, such as Local Motors, a firm based in Phoenix, are using additivetechnologies to make limited runs of cars, but 3D printing is still too slow for mass-producedvehicles. Even so, it will quickly become part of the automobile industry, says Thom Mason,director of Oak Ridge, not just for prototyping or customising vehicles but also for makingmoulds, tools and dies. That business had been largely offshored to low-wage countries. “Nowwe can print these things overnight,” explains Mr Mason.
Making things with 3D printers has captured the public imagination. In recent years, improvedhardware and software has turned the basic technology—which is about 20 years old—into abroad assortment of different processes. They all rely on building up layers of materialadditively, using plastics, metals, ceramics and even biological feedstocks. Such printers rangefrom desktop machines that cost a few thousand dollars to hulking monsters to print metalparts that cost over $1m.
The size of what could be printed used to depend on what would fit inside the machine. Nowsome printers, such as BAAM, are coming out of the box, so to speak. MX3D, a Dutch startup,plans to print a 15-metre (49-foot) footbridge across a canal, using robots fitted with steelprinting equipment. Winsun, a Chinese firm, uses a fast-drying mixture of cement and recycledconstruction waste to print prefabricated sections of buildings, and Achim Menges at theUniversity of Stuttgart is printing strands of carbon fibre to make one-off architecturalstructures such as pavilions (pictured).
Strand by strand
One of a kind
Making things with a 3D printer has captured the public imagination
One advantage of producing something additively is that material is deposited only whereneeded, so there is little waste. In traditional manufacturing perhaps 80% of the material is cutaway. Moreover, the software used to design a product can also run the printer. And softwareis easy to tweak, so a different design can be produced every time without having to resetmachines. The technique also lends itself to making complex shapes in new materials that canlead to dramatic performance gains. And although 3D printing is still slow compared withmass-production processes such as pressing steel and plastic injection moulding, in someindustries that may not matter too much.
“Additive techniques give you a whole new degree of freedom,” says Mr Idelchik at GEResearch. The company has spent $50m installing a 3D printing facility at a plant in Auburn,Alabama, to produce fuel nozzles for the new LEAP jet engine it is making in partnership withSnecma, a French company. GE will begin by printing 1,000 nozzles a year, but eventually thenumber could reach 40,000. The fuel nozzle in a jet engine is a complex part that has towithstand high temperature and pressure. Normally it is made from 20 different components.
GE instead prints the part in one go, with a laser fusing together layers of a powdered “superalloy” made up of cobalt, chrome and molybdenum. The resulting nozzle is 25% lighter and fivetimes more durable than the old sort, and conventional manufacturing methods might nothave been able to cope with the material at all.
“Additive manufacturing will definitely win a lot of ground at the expense of existingprocesses,” says Henrik Runnemalm, the head of engines for GKN Aerospace, a Britishcompany. Some of GKN’s 3D-printed components are already in aircraft and jet engines. Thetechnology is also used alongside traditional techniques. Mr Runnemalm cites an example inwhich a fine wire of material is melted to build up shapes on a component that has been castin a conventional manner. In yet another process, a 3D printer creates a component in its“near-net shape” (close to its final form), which is then finished conventionally with machinetools.
Brain scan: Carl Bass
Additive manufacturing has plenty of potential left, not least because it can change theproperties of materials as it goes along. At Oak Ridge, researchers are working on specifyingthe crystalline structure of a metal in different parts of a component by fine-tuning the heat asthe layers are built up, hoping to obtain different performance characteristics. “This is totallynew,” says Mr Mason. “It is one of those things that is not in our design vocabulary right now.”3D printing is capable of even more. Modumetal’s nanolaminates are also produced byadditive manufacturing. The process takes place close to room temperature, which meansmetal could be added to a 3D-printed plastic shape, creating hybrid plastic-metal composites,says Ms Lomasney. And the process could run in reverse, dissolving the metal in a componentback into a solution so that it could be used again. “We haven’t got into the business ofrecycling because parts are not yet being returned to us,” explains Ms Lomasney, “but intheory it’s possible.” With many new materials, recycling may become an essentialrequirement.
What next: Bright angelic mills
Though recycling will become more complicated, a much wider choice of materials willtransform manufacturing
MANUFACTURERS are coming under growing pressure to take responsibility for the life cycle oftheir products. This involves an obligation to consider all the energy, environmental and healtheffects of every stage, from materials extraction to production, distribution and, eventually,recycling or disposal. As materials become more complex, that is becoming trickier.
The traditional way of gauging what effects a new material will have on the wider world is togo by the elements. If something has lead in it, for instance, it is probably not good for you. If ithas a bit of manganese, it is probably safe. “That is so old-fashioned,” says Berkeley’s MrCeder. “Very often what these things do to your body depends on the form, not thechemistry.”
That makes nanoparticles particularly difficult. A lot of research is being done on theirenvironmental and health implications, but much of it is inconclusive. A big five-year study ofnanoparticles led by the Swiss National Science Foundation is due to be published in 2016. Oneexample of its work, from Australia, illustrates the concerns.
Being a highly developed region, South Australia gets plenty of nanoparticles in products, someof which are washed into the drainage system. It is a dry place, so much of the wastewater isrecycled, and treated sewage is used to fertilise fields. That allowed researchers from the SwissFederal Laboratories for Materials Science and Technology to study the area as something of aclosed system. From field and water deposits, they calculated the amounts of fournanomaterials that ended up in the environment every year: 54 tonnes of nano titaniumdioxide (used in sunscreens); 10 tonnes of nano zinc oxide (found in cosmetics); 2.1 tonnes ofcarbon nanotubes (hollow tubes used instead of fibres in some composites); 180 kilograms ofnano silver (for anti-bacterial use); and 120kg of fullerenes, another nano form of carbon,made up of hollow spheres known as “buckyballs”.
The final destination of these particles varied. The nano carbons remained embedded in theparts they came in, which ended up in rubbish dumps. The zinc oxide and silver werechemically converted into normal compounds in sewage-treatment plants, so did not seem topresent a risk. But the nano titanium dioxide from sunscreens went walkabout. Just over 5%ended up in the sea, the rest on fields. In its normal form titanium dioxide is not toxic (it isused in toothpaste as well as sunscreen), but the researchers say they do not know what thelong-term effects of the nano versions will be, especially in high concentrations.
Going dotty
Certain nanoparticles undoubtedly have nasty effects. Some LEDS use quantum dots—tinycrystals which when excited by an external light source glow brightly, a process calledluminescence. This produces richer lighting and brighter colours in LED televisions and otherdisplays. The dots, though, are often made from a toxic cadmium compound. That provides acommercial incentive to come up with safer materials.
Looking for the perfect LED
Nanoco, a firm based in Manchester, has developed cadmium-free quantum dots. The DowChemical Company has licensed the technology to make dots at a new factory in South Korea.
And Prashant Sarswat and Michael Free of the University of Utah have made quantum dots outof carbon obtained from food waste. This is put into a solvent and heated under high pressure.
The process still needs to be scaled up, but as the raw ingredients are free and relatively safe,the idea has promise.
For larger items, the end-of-life problems are just as challenging—and rather more visible.
Both Airbus and Boeing have programmes for recycling their carbon-fibre aircraft. In thatindustry at least the numbers are limited to a few thousand, but if carmakers were to adoptcarbon fibre on a larger scale, millions of old carbon-bodied cars would eventually have to bedisposed of. In some cases the material can be shredded and used in lower-grade components.
Recycling exotic materials might become a necessity. Some elements are expensive and hardto find; they may come from only a handful of countries, such as China, which could restrictsupply. Others, including some rare earths, are not found in large quantities and are hard tomine. Such substances are being increasingly used in electric and hybrid cars. As these becomemore widespread, new methods of dismantling and recovering materials will have to be found.
Marion Emmert and H.M. Dhammika Bandara at Worcester Polytechnic Institute inMassachusetts have developed a new and energy-efficient way to extract rare-earth elementsfrom electric cars, in particular neodymium, dysprosium and praseodymium. They sliced upand shredded the motor and other drive components from an all-electric Chevrolet Spark andused a two-stage chemical-extraction method to separate the rare earths and other usefulmaterials. The technology, they say, could be used for other products that contain motors andmagnets, such as wind turbines and medical imaging equipment.
Some firms use a process called life-cycle assessment (LCA) to work out environmentalimpacts. “The idea is to evaluate, cradle to grave, a product or service,” says ChristianLastoskie, an expert in the field at the University of Michigan. LCA used to be carried out whena product had been on the market for a while and plenty of data were available. Now it can bedone in advance with computer modelling. That means making and testing a number ofassumptions about a new material or process, but the analysis can be a useful guide topossible environmental concerns and help a company with its selection of materials, MrLastoskie explains.
One project he has worked on, with backing from Sakti3, was a comparison of the life cycle ofconventional lithium-ion batteries and solid-state ones. The results, published in 2014 in theJournal of Cleaner Production, suggested that even after allowing for uncertainties about theproperties of the cells and the efficiency of the process used to make them, the use of solidbatteries in electric vehicles would bring down energy consumption and reduce globalwarming.
All this points to the conclusion that manufacturing will become ever more complex and thatthe days of “me-too” factories, making similar products in much the same way, are numbered.
Processes such as 3D printing make economies of scale irrelevant, allowing low-volumeproduction and rapid customisation. As labour costs shrink in relation to total productioncosts, there is less pressure to move production to low-wage countries. That does not meanforeign companies will give up making things in China, but that more of the things they makethere will be for the Chinese.
With computing costs falling all the time, being able to model the manufacturing process andthe life cycle of a new material opens up markets to new entrants with new ideas. Only adecade ago it was widely thought that the world’s car industry would consolidate into lessthan half a dozen groups because the barriers to entry were so high. Now new carmakers areappearing everywhere; not just Tesla and, possibly, Apple, but also many small, specialist onessuch as Local Motors.
Big companies, too, will increasingly compete by using exclusive recipes for new materials andcustomised production techniques. “If you just do a great design and use a manufacturingprocess which everyone else can use, you will run out of steam,” says Mr Idelchik at GEResearch. “But if you have a proprietary manufacturing process which applies to proprietarymaterials, you are creating a long-lasting competitive differentiation.”Trade secrets
Mr Idelchik is not alone in that view. BMW’s factory in Leipzig uses standard industrialequipment and robots. What makes it special is the company’s intimate knowledge of exactlyhow its materials are made and how to control the processes that turn them into cars. Thisgoes to the heart of materials science. “We think we are pretty much ahead of our competitorsbecause we have the complete process and material development in our hands,” says BMW’sMr Kranz.
In future more firms will need to be on top of their materials. The days of trial and error arecoming to an end as powerful research tools deliver scientific data of unprecedented depth.
The tumbling cost of computer power makes that information available to companies of allsizes just as new production processes, such as 3D printing, transform the economics ofmanufacturing into something lighter and swifter.
Mastering the greater complexity of materials, as well as their design, engineering, production,supply-chain and life-cycle management, will require new skills and plenty of entrepreneurialtalent. It may attract more people into an industry that is still trying to shake off an image ofdark satanic mills. Manufacturing is entering a new age. Edison would have heartily approved.