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Laser Turns All Metals Black 333

Roland Piquepaille writes "Researchers at the University of Rochester have found a way to change the properties of almost any metal by using a femtosecond laser pulse. This ultra-intense laser blast creates true 'black metal' from copper, gold or zinc by forming nanostructures at the surface of the metal. As these nanostructures capture radiation, the metals turn black. And as the process needs surprisingly low power, it could soon be used for a variety of applications, such as stealth planes, black jewels or car paintings. But read more for additional references and a picture of this femtosecond laser system."
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Laser Turns All Metals Black

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  • anything special? (Score:4, Insightful)

    by Loconut1389 ( 455297 ) on Thursday November 23, 2006 @08:41PM (#16969478)
    Does this black metal have any special properties aside from being black? The article mainly talks about other ways of making it black not being as good- is that all this really does?
    • Re:anything special? (Score:4, Informative)

      by biocute ( 936687 ) on Thursday November 23, 2006 @08:48PM (#16969544)
      Low power (so low cost) makes it an ideal alternative to traditional coating/painting.
    • I'm not sure I understand the article.

      Guo's research team has tested the absorption capabilities for the black metal and confirmed that it can absorb virtually all the light that fall on it, making it pitch black.

      Surely if it absorbed all the light, it would be completely invisible, not black?

      • Re:anything special? (Score:5, Informative)

        by Tim C ( 15259 ) on Thursday November 23, 2006 @08:54PM (#16969614)
        Surely if it absorbed all the light, it would be completely invisible, not black?

        No, because if it was invisible you'd be able to see what was behind it; if it merely absorbs the light that falls on it, you'd see a black shape instead...
        • Re: (Score:3, Informative)

          by fferreres ( 525414 )
          I am sure he confused invisible, to invisible to radars and the type of systems that need a signal bounced back. You cannot use radars, but you can do motion detection and shape detection, etc. You can SEE the black thing for sure as almost nothing is pure black. It may be a good disguise in the sky though (unless you are between a start and your chaser) :-)
      • Re: (Score:2, Funny)

        by Tdawgless ( 1000974 )
        I think we need another reply telling you the difference between black and invisible. The above 3 replies were not effective. :| No body is going to read this anyways...
    • by chill ( 34294 ) on Thursday November 23, 2006 @08:54PM (#16969618) Journal
      The treated metal absorbs all incoming radiation, such as microwaves and lasers.

      Hint: Think "perfect stealth", not only for planes, but for your car as well. Make that cop toting the radar gun go insane.
      • by 1u3hr ( 530656 )
        The treated metal absorbs all incoming radiation, such as microwaves and lasers. Hint: Think "perfect stealth", not only for planes, but for your car as well.

        I don't know about that; though Roland mentions it in his typically breathless puff, TFA doesn't. I can understand these nanostructures absorbing light, with wavelengths similar to their scale, but not microwaves, radar, etc. with wavelenghths of centimetres. But absorbing all light is going to make things heat up. It will be emitting more infrared

        • Re: (Score:3, Informative)

          by Ruff_ilb ( 769396 )
          I sort of skimmed TFA and the abstract (GASP!), and they made it seem as if they could create nanostructures with different properties based on the frequency, intensity, and duration of a given pulse. While I find it unlikely that they've created something that effectively absorbs basically any sort of radiation, it's likely that with a little tweaking they can get it to absorb specific wavelengths.
    • Well because it is jet black I'd assume it probably absorbs heat from the sun pretty well.
    • by camperdave ( 969942 ) on Thursday November 23, 2006 @10:03PM (#16970058) Journal
      Does this black metal have any special properties aside from being black?

      Well, that one property alone makes it excellent for building Ford Model-Ts.
    • Re:anything special? (Score:5, Interesting)

      by MagusSlurpy ( 592575 ) on Friday November 24, 2006 @01:15AM (#16971078) Homepage
      Yes. The nanostructures formed by the laser give the metals much more surface area, thereby enabling a catalytic effect. Expect to see this played with much more in inorganic and organometallic labs very soon.
    • Yes. It is the TRUE BLACK METAL \m/, i.e. ist Krieg.
  • by TJ_Phazerhacki ( 520002 ) on Thursday November 23, 2006 @08:45PM (#16969512) Journal
    Your spaceship is ready....
  • by grub ( 11606 ) <slashdot@grub.net> on Thursday November 23, 2006 @08:46PM (#16969520) Homepage Journal

    This ultra-intense laser blast creates true 'black metal'

    Rubbish, true [youtube.com] 'black [youtube.com] metal' [youtube.com]
    (sniff... brings back memories of seeing them in '83.)
  • Comment removed (Score:5, Interesting)

    by account_deleted ( 4530225 ) on Thursday November 23, 2006 @08:46PM (#16969524)
    Comment removed based on user account deletion
  • Applications (Score:2, Informative)

    Interesting applications listed, detectors, chemistry, etc. What I'm wondering is the question implied by the editor, can this blast be used to make the metal absorb radar waves? If they can made a laser pulse make the substance absorb all visible EM radiation, can they do the same for invisible? This could have significant applications for the military if it can, not just for better stealth aircraft, but think of it. An invisible to radar destroyer, aircraft carrier, tank even. This is defiantly worth kee
    • Re: (Score:3, Informative)

      Comment removed based on user account deletion
      • Re: (Score:3, Informative)

        by John Hasler ( 414242 )
        > Whether it's also black to radio waves needs to be investigated.

        No it doesn't. It is obvious that it is not. The process makes the metal black by creating an intricate surface structure on the scale of the wavelengths of visible light. It would look like a shiny metal surface at the centimeter or so wavelengths used by radar. The effect probably peters out somewhere in the infrared.
    • Well just because it absorbs radar doesn't mean it will be invisible. If it absorbs it too well then it is simply going to look like a big blank spot in a sea of otherwise random noise. Put simply, the lack of any reflection will be just as obvious as the vehicle would be without the coating.
      • by jamesh ( 87723 )
        As I mentioned in another post, a black object (If I remember year 10 physics :) also radiates energy away more easily, which may work against it hiding successfully.
      • Re: (Score:2, Insightful)

        by Opie812 ( 582663 )
        This reminds me of something I've always wondered about stealth aircraft....you always hear about a stealth aircraft having the radar signature of a small bird. Well, if you're watching a radar screen and see a pigeon flying at 500 miles an hour wouldn't you think something odd was going on?

        Or maybe I'm just an idiot. That's always an option.
        • > Well, if you're watching a radar screen and see a pigeon flying at 500 miles
          > an hour wouldn't you think something odd was going on?

          Yes, but by the time you see it it's too late. The range at which your radar can detect an object is proportional to the size of its signature.
        • Re: (Score:3, Informative)

          the reason that the stealth aircraft with the radar signature of a small bird isn't seen is because if the radar system could see the signature of the aircraft, then it could see the signature of every small bird within the range of the radar system, which is quite a lot. and a single radar pulse is not capable of detecting speed, you need multiple radar pulses to detect speed. it's like being in a dark room with a strobe light. you can tell how fast an object is moving by gauging the distance the object ha
      • Re: (Score:2, Informative)

        Not so much. Perhaps I'm wrong, but as far as I know RADAR works by sending out a signal and picking up the reflected radiation. If nothing's reflected back it would be just like there was no object there at all. The only possible cause of the random noise you mention would be something to do with the ionosphere, and that would be so transient that it couldn't be used for accurate detection.
    • by jamesh ( 87723 )
      On the other side of the coin, back when there was an article about using lasers to take out missiles while they were in the air, someone suggested that they make them as shiny (in all spectrums) as possible to reflect rather than absorb the military laser. That would be incompatible with the idea of using the black metal for stealth.

      So I guess you have to choose... you can be really hard to find but easy to laser a hole into, or really easy to find but really hard to laser a hole into.

      One of the things I (
      • Re: (Score:3, Informative)

        by John Hasler ( 414242 )
        > On the other side of the coin, back when there was an article about using
        > lasers to take out missiles while they were in the air, someone suggested
        > that they make them as shiny (in all spectrums) as possible to reflect rather
        > than absorb the military laser.

        Doesn't work. The electric field intensity at the surface of the target is so high it exceeds the work function of the material and rips electrons right off the atoms. This creates a plasma layer that efficiently absorbs the radiation.
  • How long until you can get your logos engraved onto your laptop/ipod in black (instead of the current efforts).
  • Wow, to turn it into pure black metal, they must have to measure the femtosecond using a Dethklok [wikipedia.org].
  • Picture (Score:5, Funny)

    by duguk ( 589689 ) <`ku.oc.garf' `ta' `gud'> on Thursday November 23, 2006 @08:49PM (#16969552) Homepage Journal
    Picture can be found here [googlepages.com]

    I really should just go to bed...

    DugUK
  • by Anonymous Coward on Thursday November 23, 2006 @08:49PM (#16969554)

    and his additional references [google.com]
  • "None more black"
  • by Kanasta ( 70274 ) on Thursday November 23, 2006 @08:53PM (#16969604)
    "wall outlet" ease of the use + "it would drill a hole through your skin" = ultimate home security system
    • > "wall outlet" ease of the use + "it would drill a hole through your skin" = ...Something an ordinary electric drill will do.
  • black (Score:5, Funny)

    by Feyr ( 449684 ) on Thursday November 23, 2006 @08:54PM (#16969612) Journal
    a black engagement ring? perfect for your goth bride! Buy One Now!
  • by RobertB-DC ( 622190 ) * on Thursday November 23, 2006 @08:56PM (#16969634) Homepage Journal
    Since it's the holiday, the usual rants against the article submitter, Roland Piquepaille, have been rather muted. To sum up:

    * He gets a lot of articles posted to the front page, which makes the rest of us jealous.

    * His articles tend toward pseudoscience, or at least towards the sort of flashy, headline-inspiring science that does little to advance human knowledge.

    * He used to link to his personal blog, which really irritated people who'd love to have their own blogs get Slashdotted on a regular basis.

    * He now links to his zdnet blog, which really irritates people who'd love to have their own blogs get picked up by a big corporate website.

    * To top it all off, he's French, so all the right-wing nutters hate him automatically.

    My irritation comes mostly from the second point -- and, I'll confess, the first as well. But as his defenders (and even the Slashdot editors) have noted, it's not like he's got some inside line to CmdrTaco's desk. He just finds himself at the right place at the right time.

    Nonetheless, I recommend continuing to tag his articles with "pigpile", just so's we can keep up.
    • Actually he doesn't have that many articles posted, maybe 1 or 2 a month tops. It's just people remember his outrageous name. Sure it's a lot compared to you, but you probably don't submit nearly as many as he does.
      • by Ant P. ( 974313 )
        Heh. I didn't even notice the name until I recognised the artificial writing style and saw the "Read More".
    • by syousef ( 465911 )
      What horse shit is this? The number of times I've submitted an article and had it rejected only to see it on the front page a few days later is mind boggling. My wording is often similar or superior. While I don't take it personally suggesting that the editors don't favour particular bloggers when chosing to accept or reject a story is naive.
    • by RealGrouchy ( 943109 ) on Thursday November 23, 2006 @10:43PM (#16970320)
      Actually, you missed one of the more important aspects of the fourth point:

      He adds a link to his blog using "additional references and a picture" (or variants) as the text. This results in him getting higher google rankings for his blog, particularly for "additional references and a picture" (or variants). Note the Related Links at the top right of the Slashdot page for this article. In addition to a standard "slashvertisement", the effects also amount to a "googletisement".

      While in ordinary circumstances this could potentially be acceptable, the contents of Roland's blog entries are usually redundant (including the picture) to the very articles he is reviewing in his blog. This amounts to an abuse of the trust provided by the Slashdot community.

      Many people warn other slashdotters by adding the tag "pigpile" (for those who have tagging enabled). However, more people use the Greasemonkey script [userscripts.org] that will block Roland's pseudoscientific submissions, which brendandonhue [slashdot.org] posted in a previous Pigpile thread [slashdot.org]. That is why the Pigpile rants are low, not necessarily the holidays.

      - RG>
  • Meh (Score:5, Funny)

    by LoRdTAW ( 99712 ) on Thursday November 23, 2006 @09:01PM (#16969668)
    We all know that true black metal is Mayhem.
  • by shadow demon ( 917672 ) on Thursday November 23, 2006 @09:02PM (#16969676) Journal
    "It's the wild colour scheme that freaks me," said Zaphod whose love affair with this ship had lasted almost three minutes into the flight, "every time you try to operate one of these weird black controls that are labelled in black on a black background, a little black light lights up black to let you know you've done it. What is this? Some kind of galactic hyperhearse?"

    The walls of the swaying cabin were also black, the ceiling was black, the seats-which were rudimentary since the only important trip this ship was designed for was supposed to be unmanned-were black, the control panel was black, the instruments were black, the little screws that held them in place were black, the thin tufted nylon floor covering was black, and when they had lifted up a corner of it they had discovered that the foam underlay also was black."

    *bows to Mr Adams*

  • black... (Score:5, Funny)

    by yakumo.unr ( 833476 ) on Thursday November 23, 2006 @09:04PM (#16969698) Homepage
    black is the new gold.

    (and silver, and bronze..)
  • Solar collectors (Score:4, Interesting)

    by edwardpickman ( 965122 ) on Thursday November 23, 2006 @09:11PM (#16969750)
    Seems like the perfect coating for solar panels for hot water. The search has always been for the best heat absorbing surface. This type of coating should be the most efficent coating for heat absorbsion.
    • It is, but it also insulates a bit. If you paint something black, it emits and absorbs radiant heat with the properties of the paint, not the metal. This is about making the metal itself black so it absorbs/emits more efficiently.

      I skimmed through the full PDF and noticed that this is only a surface effect.

      So... while this may be better than every other alternative so far, how is it different than the various chemical/heat based processes that create bonds between [material] & [surface coating]? Either

    • So long as it is cheap enough.

      Of course I didn't RTFA, because that's cheating, but anodising and various paints can produce a reasonable result (say 70-80% effective) for pennies per sq foot. Since collected heat is proportional area * efficiency, you could get the same result by using 20-50% more area.

    • by dbIII ( 701233 )
      The funny thing is a sort of dull copper patina brown is nearly the ideal colour for absorbing solar radiation according to an old heat transfer textbook I used a few years back. Until then I had wondered why solar hot water heat collectors were not painted black. There must be an A/C engineer out there with such a book on their desk that can supply more detail.

      Before people refute this with silly assumptions remember that the sun does not put out white light of uniform intensity over the entire spectrum.

  • ...basically, twisted metal -> black?
  • He's BAACK! Roland the Plogger, at it again, flogging his blog.

  • blacker than the blackest black times infinity...
  • by Centurix ( 249778 ) <centurix AT gmail DOT com> on Thursday November 23, 2006 @10:01PM (#16970046) Homepage
    They found on the way that by using a nanosecond laser they produced Emo metal, which can cut itself.
  • All metals huh? (Score:3, Insightful)

    by syousef ( 465911 ) on Thursday November 23, 2006 @10:02PM (#16970054) Journal
    "This ultra-intense laser blast creates true 'black metal' from copper, gold or zinc by forming nanostructures at the surface of the metal."

    Since when were there only 3 metals known to mankind? The summary blows.

    Then you look at the articles.

    "The key to creating black metal is an ultra-brief, ultra-intense beam of light called a femtosecond laser pulse. The laser burst lasts only a few quadrillionths of a second. To get a grasp of that kind of speed--a femtosecond is to a second what a second is to about 32 million years."

    And:

    "Currently, the process is slow. To alter a strip of metal the size of your little finger easily takes 30 minutes or more, but Guo is looking at how different burst lengths, different wavelengths, and different intensities affect metal's properties. Fortunately, despite the incredible intensity involved, the femtosecond laser can be powered by a simple wall outlet, meaning that when the process is refined, implementing it should be relatively simple."

    I'm guessing this has to do with etching an intricate structure. Perhaps also that the laser can only be fired at a given rate. None of this is explained at all well.
  • So maybe.... (Score:2, Interesting)

    All the unaccounted for dark matter is covered in nanotubes.
  • by tetrahedrassface ( 675645 ) on Thursday November 23, 2006 @10:18PM (#16970158) Journal
    So i suppose I should be a little angry for my article submissions rejection this morning on this very subject. Maybe Roland is paying Slashdot to post his submissions, whatever the reasons, unlike Rolands little gem here mine did in fact note that the laser creates globules, pits and voids on the nanoscale level that dramatically increase the surface area of the treated metal.
    This technology has huge ramifications for chemical reactions that need a catalyst, and also in the area of fuel cells.

    Unlike Roland, I actually try to link to the article and not some empty blog. Roland, your technology trends suck. Link to the originating article you fool!

    Physorg [physorg.com]
    Also, does Roland even have a degree in science? Because he sure doesn't ever seem to have a grasp of the important things in the articles he submits.

  • Also Roland, the process uses a crap load of power. More in fact than the entire grid of North America focus on a pin head.

    You are a genius.

  • by Overzeetop ( 214511 ) on Thursday November 23, 2006 @10:25PM (#16970210) Journal
    I would presume that this is a very thin portion of the surface, since there is no data given, and that it sounds like it heats the metal to a vapor (maybe plasma?) and allows it to cool so quickly that it "freezes" in microstructures (excuse me - nanostructures). For all soft metals, then, a simple scratch would reveal the shiny surface free of the effects below the new "coating". Also, a surface with near zero emissivity and high conductivity would likely cause burns very quickly if left in the sun on a summer day. How would you like a nice burn from your car should you accidentally graze your spiffy black racing stripe? Also, wouldn't there be a propensity for these nano-strucutures to foul due to a microseive-like effect - collecting all the crud that just floated by? Seems like a nightmare to clean after pollen season.

    It certainly does have some applications, and optics seems to be the obvious place. Having an emissivity of (well, they didn't say) 1e-8 would certainly make baffles more efficient.
  • Researchers at the University of Rochester have found a way to change the properties of almost any metal by using a femtosecond laser pulse.

    So if I take one of these lasers and swap out the one in my CD player, will all my White Snake albums come out as Black Sabbath?
  • by schnitzi ( 243781 ) on Thursday November 23, 2006 @10:43PM (#16970318) Homepage
    Samuel L. Jackson can star in the next Terminator movie.
  • Hopefully "chaos" black, i could save a heap undercoating my warhammer miniatures then.

    Wait, i don't live in north america and have a line into THE NATIONAL GRID, guess i can't power one ;(
  • by CrazyJim1 ( 809850 ) on Thursday November 23, 2006 @11:20PM (#16970532) Journal
    Man has finally learned how to turn gold into something resembling lead.
  • During an interview at The Restaurant at the End of the Universe, Hotblack Desiato [wikipedia.org] commented about how nice this "Black Metal" accented the interior of the new Disaster Area stunt ship.
  • by Stavr0 ( 35032 ) on Thursday November 23, 2006 @11:30PM (#16970588) Homepage Journal
    If the laser can be modulated it could be used to etch a quasi-indestructible CD-ROM kind of media. For example gold or titanium could last a long while.
  • by Mr Europe ( 657225 ) on Friday November 24, 2006 @12:59AM (#16970976)
    This could hardly be used for car paintings, or any other big surfaces, since:
    "For example, blackening a piece of metal the size of a little finger currently takes about 30 minutes."
    And matt black hasn't ever been a favourite car color.
  • by Sir Holo ( 531007 ) * on Friday November 24, 2006 @02:29AM (#16971454)
    This "technology" is nothing new. Just a prof trying to make something mundane sound flashy.

    Hit things with enough laser fluence and the surface atoms will move around, and may even be blasted off of the surface. This is the basis of a standard materials synthesis technique, pulsed laser deposition (PLD) [wikipedia.org]. Hit a target with a laser, and collect the ejected material on a nearby crystal.

    Anyone who has done PLD knows that the surface of the target gets rough when you blast it. If the target is a metal, and the roughness is smaller than the wavelength of light (nanoscale), it will absorb light - it will be black.

    In any case, the article asserts that the "blackness" is a material property and is therefore permanent. Nonsense. Touch it and the surface particles will rub off, leaving behind a shiny metal surface. Further, I'd be extremely surprised if there weren't tons of existing patents on surface modification by lasers. There are certainly tons of academic publications on the topic.
    • Re: (Score:3, Insightful)

      by zCyl ( 14362 )
      Touch it and the surface particles will rub off, leaving behind a shiny metal surface.

      You don't think maybe they would have tried that before reporting the results?

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