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Diodes Could Drive Swimming Micro-Robots

Posted by CowboyNeal on from the robot-parade dept.

finisterre writes "Diodes can be made to 'swim' through salt water by hitting them with an alternating electric field. The applied field induces a current that sets up a field between the diode's electrical contacts and creates a propulsive force. The abstract of the paper in Nature Materials is freely available. New Scientist has videos of the swimming diodes in action."

14 of 51 comments (clear)

  1. Uhhh by malkir · · Score: 3, Funny

    I for one welcome our robotic sperm overlords.

    1. Re:Uhhh by dintech · · Score: 2, Funny

      No robosperm for me thank you. Because hitting them with an alternating electric field sounds like quite a painful thing to do to yourself. :P

      Then again, if implemented properly it does open a whole new realm of two-handed typing...

  2. Reading this before properly waking up... by ricky-road-flats · · Score: 4, Funny
    ... I read dildoes instead of diodes, and I can't even think of a joke for it.

    That's what I get for hitting Slashdot before the first morning coffee. Once I have that buzz I might be able to think of a punchline.

    1. Re:Reading this before properly waking up... by MightyYar · · Score: 3, Interesting

      You need to re-read that article. It simply states that coffee drinkers are no more alert than non-coffee drinkers; it does not say that regular coffee drinkers are just as alert before and after their first cup of coffee. In fact, it explains why regular coffee drinkers need the morning cup to come back up to a baseline of normal alertness.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
  3. leave your taser at home by User+956 · · Score: 3, Funny

    Diodes can be made to 'swim' through salt water by hitting them with an alternating electric field.

    And yet for some reason this same method doesn't work so well on people.

    --
    The theory of relativity doesn't work right in Arkansas.
    1. Re:leave your taser at home by Shemmie · · Score: 3, Funny

      That's not true. I connected my local swimming pool to the mains voltage to test the theory - after that, they all floated.

  4. Voltage? by AmIAnAi · · Score: 2, Interesting

    Anyone know what voltage was used here. Personally, I don't fancy being hooked up to the AC to drive nano-scale surgical robots round my body.

    --
    Any sufficiently advanced bug is indistinguishable from a feature.
    1. Re:Voltage? by Bromskloss · · Score: 2, Informative

      Anyone know what voltage was used here.

      They used an electric field of 3000 V/m to 15000 V/m. Using the distances they said they had between the electrodes, it seems that for these particular experiments, the voltage was in the range of 75 V to 1050 V.

      --
      Swedish plasma phys. PhD student; MSc EE; knows maths, programming, electronics; finance interest; seeks opportunities
    2. Re:Voltage? by Bromskloss · · Score: 2, Informative

      That's... that's a pretty large range. You sure you didn't mean to write 150 V?

      I actually meant what I wrote. I got 75 V from multiplying the weakest electric field with the shortest distance I found they had between electrodes and, 1050 V from multiplying the strongest electric field with the longest distance. That is not to say that they actually used the combinations necessary to produce these extreme values, but just that the voltages have to be somewhere in between.

      --
      Swedish plasma phys. PhD student; MSc EE; knows maths, programming, electronics; finance interest; seeks opportunities
  5. Toy + Publicity Stunt by Bender_ · · Score: 2, Interesting


    That is all there is. The propulsion principle has been known for at least a hundred years. The only 'new' thing is to use a diode to generate a DC field from externally applied AC. But actually that does not really solve any practical problem.

    1. Re:Toy + Publicity Stunt by hey! · · Score: 2, Insightful

      The propulsion principle has been known for at least a hundred years. The only 'new' thing is to use a diode to generate a DC field from externally applied AC.


      Sure, and the internal combustion engine consists of simple machines like levers and wheels that have been known for millenia, it's just arranging them so they can convert intermittent explosions into smooth rotational movement that's new.

      Finding surprising new uses for old ideas counts as a new idea.
      --
      Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
  6. Re:and what is the application? by ArsenneLupin · · Score: 2, Interesting

    I see not a single practical application mentioned with adecent justification for that application being superior or equivalent to some other method. Actually, they did mention one application: medical microrobots. And they mentioned why their method might be superior to other methods (such as a micromotor driving a ship-screw):

    But extrapolations of the team's measurements indicate the propulsive force will work just as well at smaller scales. "The propulsive force scales in exactly the same way as the drag. That's quite significant," says McKinley.
    ==> drag would be a problem for other methods, but not for this one.
  7. Re:Stealth by KokorHekkus · · Score: 2, Informative

    Not just US and russian navy but also Mitsubishi. They built the experimental boat Yamato 1 http://en.wikipedia.org/wiki/Yamato_1. Just wanted to give you a heads up before you shoot anyone for no reason you know ;-)

  8. Swimming with Diodes. by fahrbot-bot · · Score: 2, Funny
    "Diodes can be made to 'swim' through salt water by hitting them with an alternating electric field.

    Now if they can mount freakin' LASERs on them as well...

    --
    It must have been something you assimilated. . . .