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Biotech Technology

Super-Light Plastic As Strong as Steel 226

Roland Piquepaille writes "A new composite plastic built layer by layer has been created by engineers at the University of Michigan. This plastic is as strong as steel. It has been built the same way as mother-of-pearl, and shows similar strength. Interestingly, this 300-layer plastic has been built with 'strong' nanosheets of clay and a 'fragile' polymer called polyvinyl alcohol (PVA), commonly used in paints and glue, which acts as 'Velcro' to envelop the nanoparticles. This new plastic could soon be used to design light but strong armors for soldiers or police officers. The researchers also think this material could be used in biomedical sensors and unmanned aircraft."
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Super-Light Plastic As Strong as Steel

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  • How quaint! (Score:5, Funny)

    by daeley ( 126313 ) on Friday October 05, 2007 @06:07PM (#20874169) Homepage
    McCoy: You realize that by giving him the formula you're altering history.

    Scotty: Why? How do we know he didn't invent the thing?
    • Re: (Score:3, Funny)

      by mblase ( 200735 )
      The Ringworld engineers called. They have a patent for something called "scrith" and a half-dozen of the ugliest lawyers you've ever seen.
  • Obvious use (Score:2, Funny)

    by Anonymous Coward

    The researchers also think this material could be used in biomedical sensors and unmanned aircraft."
    And swords. Don't forget swords.
    • Wouldnt work (Score:3, Insightful)

      by imsabbel ( 611519 )
      Think about it: The weight of the steel is an essential part of the design of a sword. The whole reason your _swing_ it instead of "just press it against somebody" is to give it impulse that will keep it going when meeting resistance.

      Your plasteel swords would just bounce of any kind of armour.

      (lightsabers dont count)
  • Link with pics (Score:5, Informative)

    by Spy der Mann ( 805235 ) <spydermann.slashdot@ g m ail.com> on Friday October 05, 2007 @06:08PM (#20874181) Homepage Journal
    http://www.dailytech.com/Transparent+Plastic+Polymer+is+Strong+as+Steel/article9181.htm [dailytech.com]

    When i saw the title i imagined something more like bulletproof glass, but, as you can see, it's pretty thin.
    • Re:Link with pics (Score:4, Interesting)

      by debilo ( 612116 ) on Friday October 05, 2007 @06:13PM (#20874229)

      When i saw the title i imagined something more like bulletproof glass, but, as you can see, it's pretty thin.
      Thanks for the link. I wonder if this could be used as a scratch-resistant coating for sensitive surfaces. I'm thinking of my iPod and my mobile phone. Or even the windshield, loose chippings can be so annoying.
    • Re:Link with pics (Score:5, Informative)

      by kebes ( 861706 ) on Friday October 05, 2007 @06:36PM (#20874419) Journal
      The technique they are describing is called "Electrostatic Layer-by-Layer Deposition", and the resultant materials are called polyelectrolyte multilayers [wikipedia.org]. Basically you dip a substrate alternately into baths of different polymers, with each step depositing a thin layer of polymer. These materials have been studied for the last decade or so. This group is investigating layering one polyelectrolyte with strong clay platelets (rather than using two polyelectrolytes). Thus they create a "brick and mortar" assembly, where strong (nano-sized) clay platelets are glued together with flexible polymer layers.

      The process is good for creating very thin layers, but as you can imagine it's very slow for making thick materials. Each deposition step only adds on the order of a nanometer of material. Hundreds of steps are needed to create films thick enough to actually pick up, bend, and perform mechanical testing.

      However some researchers have already investigated switching from the laborious "sequential dipping" technique to a "roll-to-roll" technique. So, instead of dipping a glass slide (or whatever) into vats of liquid one after the other (each time adding a very thin layer), the idea would be to use roll-to-roll technology (like in printing presses) to dip huge sheets of material through various vats at high speed. It's been shown to work (with some difficulties along the way, of course)... so in principle if these materials become sought, there are ways of making them in greater quantities, and thicker than this lab demonstration suggests.

      Another unique thing about this "layer-by-layer" method of creating materials is that you can inherently control the composition of the material across the thickness. So you can actually have, for instance, the material's elastic modulus (or dielectric properties, or whatever), vary though the thickness of the material. Maybe you want a sheet of "plexiglass" that is super-strong at its core, but rather soft and rubberlike in its outer layer (so it doesn't hurt when you bang your head against it? Or maybe you want a liquid-like 'healing layer' on the outside to fill in scratches?). This depth-control of the material properties could be quite interesting for many applications where you want a mix of properties.

      (Disclosure: Part of my Ph.D. thesis work involved related layer-by-layer materials.)
      • Re:Link with pics (Score:4, Interesting)

        by foniksonik ( 573572 ) on Friday October 05, 2007 @07:35PM (#20874957) Homepage Journal
        How about using an Inkjet method? You could get a good compromise between speed and flexible composition... or even with the roll-to-roll method they could use something like an ink plate to deposit just where they want the liquid to bind.... lots of good engineering research to be done there as well.

        • The actual name for the process of depositing ink onto a charged drum is something like xeroxisition (I can't remember exactly, but I think Xerox got its name from the process and not the other way around.)

          But this process deposits more than a nanometer of ink (otherwise you wouldn't be able to see it), and you need to charge the ink which might not be suitable, and even if it was workable it would only help in applying the ink in a non-uniform way across a surface, and it's hard to think how that'd be u
          • Re: (Score:3, Informative)

            by Moodie-1 ( 966737 )
            Could you be referring to xerography? This is the process that photostat machines use and where Xerox got its name.
      • I'm guessing the roll-to-roll technique would also allow for drying between layers if the rollers are spaced far enough apart for the necessary drying time or by adding a heating element of some kind?
  • by User 956 ( 568564 ) on Friday October 05, 2007 @06:10PM (#20874201) Homepage
    Did they invent it by talking into the mouse?
    • Did they invent it by talking into the mouse?

      In Soviet Disney, mouse talks into you!
    • I understand that they got hold of an old Mac (circa 1986 or so), spoke into the mouse, and hit a few keys. Immediately a rotating 3D representation of the formula appeared on the screen.

      It was a lot simpler than having to actually work it out for themselves.
  • Plasteel (Score:2, Funny)

    by Anonymous Coward
    Sweet! Our soldiers can have REAL Storm Trooper armor now! Wait...that's a bad thing, right?
    • Our soldiers can have REAL Storm Trooper armor now! Wait...that's a bad thing, right?

      No, it's a really good thing. Even for the most libertarian "the revolution is coming" pessimist out there, having the Infantry in top shelf body armor is a good thing. I can only think of two scenarios where this could be viewed as a bad thing.
      1. If there ever where a need for the American people to violently turn on the government.
      - The Infantry would not be a major target. The political and economic elite would be.
  • Superman (Score:4, Funny)

    by king-manic ( 409855 ) on Friday October 05, 2007 @06:15PM (#20874257)
    Man of heavily layered plastic?
  • by erroneus ( 253617 ) on Friday October 05, 2007 @06:19PM (#20874283) Homepage
    Not sure which restaurant makes it, but there's this ultra-cheesy lasagna... it's pretty good but by the time it's "processed" it is not only as strong as steel, but as binding as epoxy.
    • Are you thinking of Safeway's 5 cheese lasagna? I think that is what they use to repair cracks in the Hoover Dam wall...
  • I know the science of materials statics and strengths, physical engineering, isn't exactly an exciting field, but might this not have applications in, say, building materials? Home-cladding? Vehicle frames? Computer cases? Ultralightweight spacecraft components? Replacements for easily-broken household items such as cups and plates?

    Why do we always have to go to "It's light! It's strong! This will clearly help prevent foreigners from killing our troops!"?

    • Re: (Score:3, Insightful)

      by TubeSteak ( 669689 )

      Why do we always have to go to "It's light! It's strong! This will clearly help prevent foreigners from killing our troops!"?

      Maybe because the military is always eager to throw piles of cash at promising technology that will improve their ability to project force & protect the forces?

      A lot of (basic) research has been done on the Dept of Defense's dime.
      Most of it has eventually worked its way into the larger market place...

      Otherwise, you have to dig up venture capital and those guys can be real bastards when you can't commercialize the technology according to their 3 or 5 or X year plan.

    • As much as I hate to admit it, military research and development drives much of what we discover these days. The government pays big $$$ for new toys.
    • Why do we always have to go to "It's light! It's strong! This will clearly help prevent foreigners from killing our troops!"?

      Sign of the times. As a civie, my first thought about the world beyond my own little life in any given day is of the war. And to the business interests who want to sell this stuff, they want a piece of those sweet, sweet billions the government is spending on this war.

    • Why do we always have to go to "It's light! It's strong! This will clearly help prevent foreigners from killing our troops!"?
      Exactly! It's equally important to prevent us from killing our own troops, right? And other people's too, for that matter.
    • Why do we always have to go to "It's light! It's strong! This will clearly help prevent foreigners from killing our troops!"?

      Because many of these materials are difficult to make, or extremely expensive, or not suited for all uses, or 'all of the above'. It normally takes many years, if at all, for exotic materials to enter the consumer market. When they do, it is typically on high end/luxury stuff first (where price is less of an object) and only later trickles down to the shelves of your local big box

    • Blame the movies. (Score:5, Insightful)

      by jd ( 1658 ) <imipak.yahoo@com> on Friday October 05, 2007 @07:00PM (#20874611) Homepage Journal
      How many movies have you seen where the hero rescues household finances by preventing the cups from getting broken? Or builds a 200 mpg car by replacing the iron shell with plastic, preventing the total collapse of the US car industry and Western Civilization?

      Let's face it, mundane (but realistic) uses aren't exciting and don't make good stories. The microwave gun that generates pain across nerve endings is discussed in terms of urban combat and riot-suppression, but in the real world, more people are probably going to end up using the device in farmland where electric fences are impractical or impossible, as a replacement for noisy bird scarers, possibly even in a very low-power form in medical diagnostics when you want to generate a very controlled stimulus to determine the location and extent of nerve damage, etc.

      An ultra-light plastic would be valuable for so many things, from cutlery to possibly safer alternatives to metal for pins and plates within the human body to a replacement for aluminium in airframes to a replacement for metals (lead especially) in "unbreakable toys". Depending on thermal properties, it may have uses in ducting where you need something strong but light. Depending on exactly what is meant by "strong", it may become a replacement for steel cabling in reinforced concrete - plastics tend to be better at aging. Current plastic drains are notoriously feeble. Now, please consider that Victorian drains are only now starting to reach the end of their lifespan, and Roman-era aqueducts are still perfectly functional, so anything that lasts a mere hundred years is simply living up to what was expected of material science a hundred years ago, and we really should be looking to match or better a bunch of iron Age punks. Could this plastic offer a cost-effective way of matching some of the greatest material science achievements in history?

      • I'm excited, not by what this can do, but by the concept itself. Imagine if, instead of using montmorillonite clay and polyvinyl acetate, they used bucky tubes and a stronger polymer and instead of just making sheets, twisted those sheets into strands. Might just work for a space elevator.
      • Re: (Score:2, Funny)

        by Anonymous Coward
        An ultra-light plastic would be valuable for so many things, from cutlery to...

        Assuming the material (or some variation of it) has the necessary properties make good "cutlery", metal detectors installed for safety are suddenly less effective. If the material could be made in thick (or even millable) configurations, the plastic handgun becomes a possibility (no, Glocks don't count - they have plenty of metal parts to set off a metal detector). And Wandering Wombat was concerned that someone's first thou
      • Or builds a 200 mpg car by replacing the iron shell with plastic, preventing the total collapse of the US car industry and Western Civilization?
        Just think how many more mpg it would get if you built a bicycle out of it instead
      • Those are, sadly, excellent points. I cede my original post as maybe a little one-sided, or at least ignorant of the unfortunate truth.

        *sigh* I still want unbreakable beer mugs.

    • Re: (Score:3, Insightful)

      by ampathee ( 682788 )
      Because that's where the grant money is?
    • by GroeFaZ ( 850443 )
      You should have realized by now that everything with even remote military applications has better chances of receiving research money. In the US at least.
    • While I'm sure there's a certain subset of people who read this article and immediately turns to a friend and says, "Do you even BEGIN to realize the profound effect this development will have on laptop cases?!?" the idea of super-thin bullet-proof vests are probably a lot more exciting to most people.
      • I admit it, I'm a geek. My first thought was to wonder if this would replace aluminium, as aluminium replaced titanium, in Apple's pro laptops. My second thought was to wonder how well it radiate heat.
    • by sholden ( 12227 )
      Obviously you seek out the things that have the most money first...

      There's also the question of what "strong" means. High tensile strength but low compressive strength does not a good support beam make.

    • Because the US is an aggressively militaristic and jingoistic culture that glamourizes and fetishizes the military and its weapons.
      • by shmlco ( 594907 )
        Hey, it's not like we have TV shows and in fact entire cable channels devoted to military tactics and history and weapons and ... oh.

        Never mind.
  • "Michigan Engineering is seeking to raise $110 million for capital building projects and program support in these areas to further research discovery"

    Ah... sounds like there might be some PR hype lurking in here somewhere...
    • by Da_Biz ( 267075 )
      Ah... sounds like there might be some PR hype lurking in here somewhere...

      Well, I think it's safe to assume there's PR hype because this is a press release. The little blurb at the end is nothing terribly shameful or surprising.
  • Strong as Steel? (Score:5, Insightful)

    by trout007 ( 975317 ) on Friday October 05, 2007 @06:29PM (#20874365)
    I hate that comparison. Are they talking Yield Strength or Ultimate Strength? What is the Modulus of elasticity? If you are talking strength there are many different steels with widely different strengths. Also if you are talking body armor there is also it's energy absorption capability.
    • Re: (Score:3, Informative)

      by SoapDish ( 971052 )
      Judging from the description of the "Velcro effect" I'd wager they're talking about ultimate strength. And even then, they may be talking about specific strength, so it could actually require a much larger geometry to achive the same strength as steel.

      And yes, yeild strength and ultimate strength are very different quantities when it comes to design (for those that don't know).

      The layered construction makes it sound like the material's not isomorphic, and I bet there are different compression and tensile ch
      • by Toonol ( 1057698 )
        The layered construction makes it sound like the material's not isomorphic, and I bet there are different compression and tensile characteristics.

        I know almost nothing about material science. But if a layered material exhibits most of it's strength along one axis, couldn't the same process be adapted to use (for lack of a better term) threads? Multiple fine threads of distinct material bonded together, forming a type of cable. Wouldn't that show structural integrity along two dimensions instead of on
        • Well, I made a mistake in that most. It should read isotropic, not isomorphic - I knew it sounded wrong.

          Anyway, an isotropic material has the same properties in all directions - eg steel or aluminum (unless coldworked). An anisotropic material doesn't - eg fibre composites.

          Fibre composites are strongest in the directions that the fibres run, and weaker in a direction perpendicular to the fibres. There are all sorts of weaves to control this, even 3-dimensional weaves.

          Laminar/layered materials tend to be wea
    • Re:Strong as Steel? (Score:5, Informative)

      by kebes ( 861706 ) on Friday October 05, 2007 @07:13PM (#20874771) Journal
      If you're interested in the details (and have a subscription to Science), here's the actual paper:
      Paul Podsiadlo, Amit K. Kaushik, Ellen M. Arruda, Anthony M. Waas, Bong Sup Shim, Jiadi Xu, Himabindu Nandivada, Benjamin G. Pumplin, Joerg Lahann, Ayyalusamy Ramamoorthy, and Nicholas A. Kotov "Ultrastrong and Stiff Layered Polymer Nanocomposites [sciencemag.org]" Science 5 October 2007: 80-83. DOI: 10.1126/science.1143176 [doi.org].

      Deposition of alternating nanoscale layers of clay particles and a polymer yields a transparent composite that is as stiff and strong as steel.
      The abstract is:

      Nanoscale building blocks are individually exceptionally strong because they are close to ideal, defect-free materials. It is, however, difficult to retain the ideal properties in macroscale composites. Bottom-up assembly of a clay/polymer nanocomposite allowed for the preparation of a homogeneous, optically transparent material with planar orientation of the alumosilicate nanosheets. The stiffness and tensile strength of these multilayer composites are one order of magnitude greater than those of analogous nanocomposites at a processing temperature that is much lower than those of ceramic or polymer materials with similar characteristics. A high level of ordering of the nanoscale building blocks, combined with dense covalent and hydrogen bonding and stiffening of the polymer chains, leads to highly effective load transfer between nanosheets and the polymer.
      In response to your questions about actual material response, the paper discusses a variety of metrics for a variety of different preparation conditions. They report that the nano-composite material has an ultimate tensile strength 10 times greater than the pure PVA polymer, up to 480 MPa. They also state that the modulus, E, was 100 times greater than the pure polymer, up to 125 GPa, which they compare to Kevlar (E ~ 80 to 220 GPa).

      In terms of energy absorption, they compare the uncrosslinked nano-composite to the crosslinked one. As you might imagine, the crosslinked one was more rigid (and gave rise to the modulus previously mentioned), having a low ultimate strain of 0.33 %. The uncrosslinked one deformed somewhat more (ultimate strain 0.7%), with higher energy absorption potential.

      As you note, the comparison of "strong as steel" is not very helpful. But looking at the stress-strain curves, these materials look quite strong. Also, since you can adjust the material properties (optimizing for energy storage versus elastic modulus), they might be great for achieving desired performance for certain niche applications.
  • So if it is clear, would that meant that Wonder-Woman isn't far behind??
  • Ya know, I'm not opposed to this technology being used to protect police officers and soldiers, but something in me cringes when that is the first suggested use listed in the article. We seem so hell bent on aggression and security that peaceful and scientific uses are at the bottom of the list or altogether neglected. For instance - this stuff might make motorcycle racing even more interesting - both from a rider's safety standpoint and bike technology.
  • Plasteel (Score:4, Insightful)

    by Ramble ( 940291 ) on Friday October 05, 2007 @06:35PM (#20874409) Homepage
    Plasteel, anyone?
  • PVA... (Score:2, Informative)

    by Alceste ( 138400 )
    Dissolves pretty readily in water. I wonder how this is stabilized.
    • Re:PVA... (Score:5, Informative)

      by kebes ( 861706 ) on Friday October 05, 2007 @07:21PM (#20874841) Journal
      It turns out that these kind of materials are not water-soluble, even though both components are, and even though you can easily assemble them from water. It's certainly counter-intuitive, but the assemblies involve electrostatic (charge-charge) links and hydrogen-bonding (like in DNA) links. Even though those kinds of links are inherently water soluble, when you are layering "large" molecules (polymers and nano-platelets count as large in chemistry), then there are so many "sticker groups" that the overall binding is very strong. (There are other more subtle effects, like the entropy of assembly, also at play.) As a result, these materials don't readily dissolve in water.

      In the actual scientific paper, they further explain how they "cross-link" the material to make it more stable. Cross-linking is basically chemistry that generates strong covalent bonds between the various molecules. (This is what happens when you make a strong rubber...) They do indeed indicate that the cross-linked materials are more stable against changes in humidity (the un-crosslinked materials swell a bit when exposed to a humid atmosphere; which might be bad for some applications).
  • I watched the Super Friends growing up, I know how this ends [bcdb.com]! Marvin and Wendy had to foil a plot from a guy named "King Plasto" who used stuff just like this in his evil attempt to take over the world. Someone call the Great Hall Of The Justice League and get Batman and Aquaman on this, stat!

    To think I can remember that bad episode of a bad cartoon from the 70's, yet forgot my Dad's birthday this year. Again.


  • They should start making condoms out of this!
  • by UnAmericanPunk ( 310528 ) on Friday October 05, 2007 @06:44PM (#20874477) Homepage
    So... why not make cars out of this stuff? Think, if it's as strong as steel, if the car body was made out of this then it would be like having a armored car, or at least a 50's American car. Then with the lighter weight it should improve gas mileage quite a bit. As long as the manufacturing process isn't too costly or cost goes down with more production, this sounds like it would be great.
    • So... why not make cars out of this stuff?

      I agree, to a certain point. Cars need a minimum weight as to not be pushed by lateral winds, so I don't think making the WHOLE body of this stuff would be a good idea. Having said that, this plastic could be a wonderful extra layer of protection for your car.
      • There are a lot of heavy parts of a car that are probably not appropriate for plastic, especially an expensive plastic. Engine block and bearings come to mind, gears, radiator, electrical wires...

        Better windows would be a real plus. If this stuff is transparent and can be engineered to be as flexible as steel, it would have a big advantage over the dangerous stuff we're using now.

        • by barzok ( 26681 )
          As long as it doesn't scratch easily. Lexan® is a terrific material, but in most applications it scratches very, very easily.
    • As some people have pointed out, 'strong as steel' is really not much of a definition. Since it's a layered clay composite, it's probably fairly brittle. This means in applications where it needs to bend it will shatter. This is probably not what you want your car to do. OTOH, as ablative armor or in your car's structural members this stuff might work really well.

      So... why not make cars out of this stuff? Think, if it's as strong as steel, if the car body was made out of this then it would be like havin

    • Re: (Score:2, Interesting)

      Feel free to correct me on any of this as maybe it is a preconception about plastics but.... I'm pretty glad cars aren't made of this stuff as it seems it would be a lot less recyclable than using a metal, give it fifty years and we would have landfills full of the stuff.
  • i just want to know steel at what temperature.
  • Or the cops... or soldiers.. or anything but the 'common citizen'.

  • there they had a bioplastic that was used as building material, in various strengths.

    as the name suggests, it was grown using bacteria.

    hell, one book even had a "inflatable" structure. just pump in nutrient and it would erect itself, complete with windows and pre-fitted wiring.
  • Your bullets cannot harm me!

    My wings are like a shield of steel!
    • by mark-t ( 151149 )
      I loved that show [wikipedia.org] when I was a kid! By the way, it just came out on DVD this summer... so us nostalgia buffs can watch all 100 episodes anytime!
  • at what temperature does it melt?

    it's plastic. not steel.
  • Biotech? (Score:5, Insightful)

    by Biff Stu ( 654099 ) on Friday October 05, 2007 @07:47PM (#20875093)
    Does anybody who creates the tags RTFA? (OK, I'm not new here. That's meant to be a rhetorical question.) I don't see how this is biotech. The stuff is made out of sequential layers of clay and PVA. These layers are deposited mechanically from solution. It's not like they have genetically engineered critters secreting some new cool substance. Yes, the researchers do compare the structure to mother of pearl, but other than a structural simularity, that's all there is.
    • the researchers do compare the structure to mother of pearl

      Would that not make it a biologically inspired material? Close enough to biotech for me.
  • ...is packaging!

    As if blister packages weren't nearly impossible to open now. Hmm, let's cut with a scissors on the edge so the further you cut, a plastic blade starts to form that convieneintly moves toward your hand.

    Now we need a plasma cutter to open up the packaging to our latest gadgets?
  • But, can they replace the clay with carbon buckey tubes, draw a long filament, and make a space elevator out of it?

A committee takes root and grows, it flowers, wilts and dies, scattering the seed from which other committees will bloom. -- Parkinson