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A Thermometer In A Nanotube

Posted by timothy on from the they-nab-you-with-the-scope-rental dept.

Stone Rhino writes: "Yet another marvel has been created in the quest to create minature machines: a thermometer of liquid gallium within a carbon nanotube. The New York Times has an article on this. The thermometer is 10 microns long and measures temperatures from 120-950 degrees farenheit. Of course, the part I find most impractical about it is the fact that you need a scanning electron microscope to read it."

7 of 18 comments (clear)

  1. Sure the thermometer is small by Anonymous Coward · · Score: 2, Funny

    But do you want that scanning microscope stuck up in your ass as well?

    Well, okay, but do you want it in there the whole time they take your temperature?

  2. sounds interesting... by Hadlock · · Score: 3, Interesting

    a better use of this (does this even have a use, other than proof-of-concept yet?) might be to, um, install one of these on nanobots, and have the liquid metal spurt from the end....somehow alerting the operator that the nanobots are about to overheat.

    that's fascinating though, i was under the impression that carbon atoms were pretty small, and a nanotube would only be about 6 atoms across...from what i recall, lithium is pretty far away from carbon on the periodic chart. how does one fit one (or more) lithium atoms inside this tiny tiny tube?

    --
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    1. Re:sounds interesting... by CounterZer0 · · Score: 4, Insightful

      A) Lithium isn't very far away, it's element #3 (to Carbon's 6), so it's ultra tiny.
      But that's irrelevant, as this thermometer uses Gallium is #31 (the first element to be predicted before it was discovered), and Gallium is much bigger than carbon. But that's why the carbon is arranged into tubes - multiple atoms across, able to hold gallium atoms.

      What I want to know, is if using the SEM to read the temp changes the temp? All those impinging electrons must raise the kinetic energy of the Gallium atoms at least a little?

    2. Re:sounds interesting... by caffeinated_bunsen · · Score: 2
      Gallium is metallic, and conducts fairly well (resisitvity=14.7 micro-ohm*cm, probably a bit different in the liquid phase).

      The diameter of the tubes, as quoted in the article, is 75nm (that's a lot more than one carbon atom across). The average interatomic spacing of liquid gallium atoms is .26nm, if I did my math right. So the tubes are ~300 gallium atoms across. (BTW, these sound like some exceptionally wide nanotubes.)

      As for changing the temperature of the thermometer by reading it, there is of course some change. But at that scale, thermal conduction is pretty much instantaneous, so you heat up the whole system (gallium, carbon tube, and whatever it's mounted on) at once. The change in temperature of the entire system from the electron beam is presumably negligible.

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      Bugrit! Millenium hand and shrimp!
  3. In a related note, British scientists... by Single+GNU+Theory · · Score: 2, Funny

    ...asked about carbon nanotube thermometers revealed about their own research: "These go to eleven (microns)."

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    Little Debian: America's #1 Snack Distro!
  4. It seems weird now, but... by steve.m · · Score: 2

    When the First transistor was made, who would have predicted how we'd be using them now?

    This thermometer probably isn't too useful on its own, but just shows that stuff you can build from 'big' components can also be done in nano scale.

    I wish I was working in nanotech....

    1. Re:It seems weird now, but... by markj02 · · Score: 3, Informative

      The inventors of the transistor would have predicted it. The transistor was quite explicitly intended as a replacement for bulky vacuum tubes with inconvenient power requirements, and that's how we are using them.