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Photonic Breakthrough Allows 'Lab-on-a-Chip' 72

Roland Piquepaille writes "Georgia Tech researchers have shrunk an optical device called wavelength demultiplier (WD) by combining into one crystal three unique properties of photonics crystals. This optical discovery opens the way to sophisticated and cheap bio-sensors mounted on 'lab-on-a-chip' devices -- sensors to run blood tests, detect chemicals in water supplies or for drug testing. Their new WD is less than a millimeter in all dimensions rather than the several centimeters of other currently available WDs. And it should not cost more to produce."
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Photonic Breakthrough Allows 'Lab-on-a-Chip'

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  • Typo? (Score:2, Informative)

    by packeteer ( 566398 )
    And it should not cost more to produce."

    Cost less hopefully?
  • by gpn ( 991395 ) on Monday August 07, 2006 @07:40AM (#15858118)
    40 WDs = 40 x WD = WD40 ?
  • WD for computing (Score:3, Insightful)

    by gigne ( 990887 ) on Monday August 07, 2006 @07:44AM (#15858126) Homepage Journal

    Now the key components for processing light have been miniturised, it should be possible to use this for the basis of a simple optical computer.
    From the sources below: rystals/ []
    The design also eliminates problems of wavelength interference, which means that although the crystal is tiny, it will work at very high resolutions - between 64 and 100 microns.

    So... it seems like the photonics are ready. We just need engineers to step up to the challenge.
    • I thought optical computing required Wavelegth Mass Demultipliers and it was a bad thing ? At least that's what this guy from the US was blabbing about on the TV, he seemed very excited about the whole thing.

      Besides 3GHz ought to be enough for anybody... Well I'm not sure he actually said that but that's probably what he hinted at, it's a bit fuzzy now, it didn't make much sense now that I think about it...
    • Possible ideas? (Score:2, Interesting)

      by DeadCatX2 ( 950953 )
      Put some small, fast phototransistors into silicon. Use glass tubes (glass = Si) to propagate the signal to the next point, free of capacitance; maybe we can even tune the permittivity of the glass so the light can propagate faster. Build these crystals and tie them into the silicon to sense the signal and turn it back into a logic level.

      Ideal for long hauls where the capacitance is a major factor in the switching speed, or clock distribution trees. The lowered capacitance, and possible increased permitt
      • Si can be used for photodetectors, but as an indirect bandgap material, it is very difficult to get it to generate light. Also, glass is SiO, not Si. Also, the big trick with optical waveguides is getting them to turn sharp corners so you can fit a reasonable number of interconnects on a chip.
        • LEDs generate light, don't they? Granted, I know there's rise-time characteristics and for LEDs they probably suck, and that might be the difficulty you mention.

          Thanks for the clarification on the glass thing. I knew Si was involved somehow...heh.

          Isn't SiO2 used in chips? How hard could it be to make SiO?

          And I thought that this thing handled that big trick. I mean, 60 microns by 100 microns is pretty big in terms of processor size features. But if you could multiplex a whole bus of 100+ bits into one s
  • by lisaparratt ( 752068 ) on Monday August 07, 2006 @07:49AM (#15858138)
    drug testing

    The War On Drugs is sooo last century - didn't they get the memo that we're fighting the War On Terror now? They haven't sensationalised it enough - they've got chemical attacks on water supplies in there, but it's too subtle - where's expolsives detection at customs on their list?
    • The War On Drugs is sooo last century - didn't they get the memo that we're fighting the War On Terror now?

      No, the War on Drugs is over politically (though no one will admit they lost the war. But the War on Drugs is still very much alive in sport -- at every level from high school to professional.

      This will ideally just make it cheaper to test the other teams' 8-year-olds for EPO and synthetic testosterone to make sure they're not getting an unfair advantage over our non-cheating good-sportsman hard-work

      • Yeah, I could imagine putting the thing in a smallish computer. That way you could get a sample of something, run it past the chip, and get a readout of what it is. Then you could scan people very efficiently, and find out who's carrying explosives or steroids (I think you's still need blood, unless steroids are capable of becoming airborne), or any number of other things.

        I would get a patent, but I think someone beat me to it... []

      • And you thought RFID "chipping" was evil. Wait until all job applicants, athletes, etc. are required to have an embedded blood testers with satellite uplink. Couple that with the "soon to be invented" embedded mind probe that can detect "criminal thoughts" (which will be easy to justify - think "protecting the kids from pedophiles.")

        With our increasing police/nanny-state mentality, does anyone else think that this is a possibility? Remember: We already have thought-crime laws (aka "hate crime" laws. It's no
      • I do not think that they have lost the war, but the political attention seems to have shifted to sports doping. This technology should prove helpful on that front, as doping is a major problem.
    • by Silver Sloth ( 770927 ) on Monday August 07, 2006 @08:20AM (#15858215)
      Maybe I'm dumb, but I read it as 'testing drugs' - monitoring the changes in the body when certain drugs are used. As someone who is (remotely) involved in Medical Research I feel this is a Good Thing (TM).
      • And better yet, smaller internal devices that could sense the minute changes in blood glucose. Reducing the need to do multiple finger sticks, just one step closer to a closed loop insulin delivery system.... Just a food for thought.
    • Just wait until TFA makes it to the nightly news. It is the media, after all, that adds all of the spin.

      And tonight on NBC10 News at 11, a new discovery that will make it easier to protect the nation's water supplies from terrorist attack. You see, our water supplies are at risk. All a terrorist has to do is come here, 3 miles NW of I-95 exit 37, and add between 1 and 2 quarts of chemicals to this reservoir to endanger millions in the Philadelphia area. They had better do it soon, however, as this new

  • propagating typos (Score:4, Informative)

    by geeber ( 520231 ) on Monday August 07, 2006 @07:49AM (#15858140)
    That's a "wavelength demultiplexer". It is wrong in the original article.
  • by coinreturn ( 617535 ) on Monday August 07, 2006 @07:50AM (#15858141)
    The error is in both the article summary and one place in the article. The proper term is "demultiplexer," not "demultiplier." A "demultiplier" is called a "divider."
  • by pimpimpim ( 811140 ) on Monday August 07, 2006 @07:52AM (#15858149)
    There's a whole journal devoted to lab on a chip [], bringing this small part of the technique as the only thing needed to make labs on a chip (lab on a chips?) is a bit of an overstatement

    As a scientist, this is what I don't really like about scientific journalism. Like the 'New breakthrough in fighting cancer' titles, etc. etc. These are laboratory research developments and will take at least 10 years to evaluate, some of them will end up being impractical before ever being put to use.

    I think that scientific journalism should be more than just a PR machine for research labs. Of course they want the message out that they're doing nice stuff, but as it are all just small pieces of advancement, don't bring it as if you just developed a working nuclear fusion reactor ready to connect to the powergrid. Show that you're doing someting nice, what it can do, what the scientific/technical genial idea is that was done to get it, and in what frame we should see it, that should be enough.

    • by amide_one ( 750148 ) on Monday August 07, 2006 @08:34AM (#15858261) Homepage
      Only trouble with that is that scientific journalism isn't aimed at scientists; it's aimed at the generally-educated layman, who outnumber scientists hundreds to one. And so the average reader isn't going to be very impressed by "this new device could allow the integration of another optical component onto the chip rather than the reader, reducing the cost of the reader and the risk of carryover" -- or at least, he'll find "will allow 'lab on a chip' devices" a lot more impressive. There's already plenty of literature aimed at scientists.

      Scientific journalism really *is* PR; the reason universities and "Scientific American"-type magazines publish these things is to show people what science is doing lately... and why you should encourage your kids to grow up to be scientists, why you should write to your Congressman to support the NIH, why you should make a generous bequest to your alma mater, etc.

      That said, it really isn't correct to report an incremental advance as more than that. (And not even one actually ready yet for micro-TAS systems; they demonstrate a device optimized for 24 channels over 1.5-1.6 um.) Not to say that it's not an impressive bit of work.
      • But my point is that the layman, just as I, just won't believe any 'new cure against cancer found' claims in the newspaper any more, as everyone already saw hundreds of these statements in the last 20 years, and no one ever worked out yet. Which is not to say there was no development in this field!

        I agree that we scientists need funding, and need to pass the message of the beauty of our work in an understandable and attention-drawing manner to the ones giving the funding, and the public in general. But, a

    • It's all about funding.... in a perfect world one wouldn't have to sell the merits of their research... or at an institute like MIT, CMU, Stanford, etc. where they've apparently found ways to grow money on trees :)... however at most state universities this type of PR is, unfortunately, necessary.
      • Every single school, from the community college on up, is going to do everything it can to convince its alumni, students, faculty, and benefactors that it's doing useful and important work. Even " MIT [], CMU [], Stanford [], etc." issue the exact same kind of PR. It's necessary everywhere.

        The Bad Thing is confusing the explanation in the PR with the real research or discovery, or assuming that it's actually important because the school PR office thought it sounded neat. Which is how Roland Piquepaille wound up pr
        • of course, I'm not arguing with you. I agree whole-heartedly that articles like this degrade and dilute quality work. I'm just pointing out the unfortunate necessity of it. Though, yes, it can be done in a better manner than the aforementioned example.
          • Not to continue this ad infinitum, but why is it "unfortunate"? Should alumni give money whether or not they think the school's doing anything useful? Those schools that have huge endowments got them by persuading the world they're worth funding -- in part through PR. :)
            • this is true. However, I know firsthand that many in the research community feel pressure to "spice" up projects and spend significant portions of their time working on making their research efforts marketable rather than pursuing their intended goals. This is the only thing I find unfortunate, although it is the way the world works so perhaps there's no point in bemoaning it :)
    • Very good points, but, interestingly, the article is on Georgia Tech University's own site, so you'd think the academics themselves might edit the "journalism" and get it right! More likely though, they're talking it up so that
      (a) they can get more grant funding
      (b) the technology can be licensed out
      (c) a spinout company is looking for investors
      • Of course they're looking for more grant funding. Everyone is, always. :)

        At least at my school (and apparently at Georgia Tech as well), there's a separate "news office" that does the reports like this -- an internal "journalist" (or half reporter, half PR person) comes to the lab and interviews the professor when they get wind of something impressive/marketable. They write the article, based on background and specifics given by the professor. They distribute it, via the university's website and alumni ma
      • It always amazes me how often people (and even Sports memorabilia manufacturers!!) append University to colleges that don't include it in their name. You dont call Boston College, Boston College University or MIT Michigan Institute of Technology University do you?

        Not that the proper full name is on the website you say you looked at, or in its logo, or anywhere else</offtopic>


  • by Richard_at_work ( 517087 ) <> on Monday August 07, 2006 @07:57AM (#15858162)
    Poodle-on-a-chip, jackrussell-on-a-chip and the all time favourite alsation-on-a-chip.
  • by Anonymous Coward on Monday August 07, 2006 @08:00AM (#15858172)
    Makes me wonder about using an array of them in a camera in order to record colour images in terms of their actual spectral content instead of approximating down to red, green and blue. Then just run them in reverse (I assume the optical demux can be used in reverse) to re-create the display.

    This would make a convincing display even for those with colour blindness or []tetrachro matic vision.

    As an aside, it has been mentioned that humans with tetrachromatic vision can see through various types of man-made textiles ;-)

    Sadly, human tetrachromatic vision occurs only in females :-(
    • Makes me wonder about using an array of them in a camera in order to record colour images in terms of their actual spectral content instead of approximating down to red, green and blue.

      Hmmm, I wonder if their wavelength demultliplexer could be used as a phase demultliplexer. If so it should be possible to digitize holograms, perhaps even in color.

    • IIRMECC (if I remember my electronics class correctly). Muxes and DeMuxes are complimentaries of the other, but they cannot be "used in reverse". This my not apply to optics, but I'd wager that they wouldn't use the logical circuit naming if it wasn a near parallel in operation.
    • I can see through some man made textiles worn by women, too. And not only me. On fashon shows teher are many women in transparent textiles :)
    • Sadly, human tetrachromatic vision occurs only in females :-( - which of-course completely negates all of the positive sides of this ability.
  • sensors that can detect trace amounts of a chemical in a water supply or a substance in your blood -- onto a single microchip.

    Now you can be busted in record time by a computer that detects the trace residuals you acquired during the Radiohead concert you went to weeks ago.
  • LabManPower (Score:4, Interesting)

    by Doc Ruby ( 173196 ) on Monday August 07, 2006 @08:53AM (#15858318) Homepage Journal
    Great! So now I should be able to get a little lab on a chip that analyzes the air and water around me, wherever I go, for pollutants and toxins. Am I glad that we've got the Clean Air Act and Clean Water Act that keep my personal environment clean.

    Wait, my old chips are telling me that those "clean" Acts are really "dirty" []. And since the police will arrest you when you photograph them [], it's going to be tough on people getting the dirt on polluters.

    Or maybe these little LabMans on every allergic person's mobile phones will force a change on all that. Will the government be able to lie to us about our pollution laws being "Clean" laws when our phones are chirping whenever we leave our oxygen tents?
  • by Dan East ( 318230 ) on Monday August 07, 2006 @09:01AM (#15858339) Journal
    I'm sorry, but anytime I see some new invention (bet it instrumentation, drugs, etc) related to healthcare, and they talk about how cheap it will be, I can't help but thing "yeah, right". Maybe it's cheap to produce, but by the time this patent is grabbed up by a money grubbing corporation, then endures the expensive and drawn out FDA approval process, and finally the owner determines the maximum that Medicaid and other insurers are willing to pay for the test, it will hardly be cheap. By cheap they really mean "greater profit margin than with existing technologies".

    Dan East
  • So we're one step closer to Tricorders
  • by PhysicsPhil ( 880677 ) on Monday August 07, 2006 @09:52AM (#15858579)
    The only thing that is interesting about this article is the fact that they've done it with photonic crystal waveguides. My own lab the same thing with silicon-on-insulator waveguides (not photonic crystals though). We are currently testing various biosensors, including a high-resolution (2 Angstrom target) spectrometer for interogating atomic spectra. On of our other designs has been shown to measure sugar concentrations in water, and we're moving to detecting actual biomolecules over the next few weeks.

    These guys have great PR but, like most scientific advances, the improvement is really only a tiny step.
  • I went to some presentations at UC at Berkeley bak in 2000. They had developed and were testing some WDM-on-a-chip, with integrated receivers/transmitters.

    I klicked on the link in this article hoping to see what development had occurred over the last 6 years. To my surprise the article has nothing useful in it. Yes, thats right. No info on:
    -frequency, (Is this in the 193THz IR band?)
    -spectral resolution,
    -insertion loss,
    -return loss,
    -polarization modes,
    -passband characteristics (Is

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