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Fluid control

  1. Dec 13, 2005 #1
    Hello everybody,
    I need to search for techniques for the next problem:
    I have a germ/cell and I want to put it inside a liquid drop.
    I need to build such an electronic tool, so the "customer" will take his different liquids, and automaticly, the "machine" will put a germ inside each liquid tube.
    I thought of the next stuff:
    microfluids.
    flow cytrometer.
    a device like in the inkjet, using a pizoelectric crystal to "shoot" germs instead of ink.
    The think is i am not familiar with those,
    so - do you have any simplified explnations? name of an easy book?
    Maybe you have good suggestions for my project?
    Thanks,
    Bsc student,
    Hanan.
     
  2. jcsd
  3. Dec 13, 2005 #2

    Danger

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    An intriguing problem. If you need to inject precisely one germ into each drop, I suspect that you'll have flow control problems with the germ injector. Isolating a drop of water to put it into will be simple, but I have no idea how you cut one germ from the herd. Somebody from Biology might be better suited to field that one. Moonbear, where are you?
     
  4. Dec 13, 2005 #3

    Danger

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    Stop the presses!
    I stopped at the pub on the way home, and half-way through a pint of Keiths something came to mind. Damned near drowned myself slugging it back to come back to PF. Unfortunately, it's probably neither practical nor economical.
    It just occurred to me that a SciAm article a few months ago about nanotech mentioned a molecular 'conveyor belt'. It essentially just shuttled stuff along a polymer chain or something like that. I wonder if one of those little buggers could be trained to grab germs.
     
    Last edited: Dec 14, 2005
  5. Dec 14, 2005 #4
    SciAm article

    Thanks danger.
    I'll try looking for this article. I guess it will be much easier if you knew perhaps what around which month it was. 2005?
    Thanks.
    Hanan.
     
  6. Dec 14, 2005 #5

    Danger

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    I'm afraid that I have no idea about that, but I'll try to find out. My sense of time is almost non-existent, so it could be anywhere from 3 months ago to 3 years ago and I wouldn't be able to tell the difference. Unfortunately, I also don't remember the title of the article, and there have been a half dozen or so about nano devices. Once I get to work I'll start snooping around for it.
     
  7. Dec 14, 2005 #6
    more explanation

    Hey,
    Danger - thanks for your efforts. Just to make sure we undersand each other, i'll give more detail:
    Essentially, let's say I have this tube , and it contains some sort of liquid. Now I am looking for a technology, that will enable me to move droplets of the liquid over lengths of microns. so, I'll bring each droplet to its own tiny sit. (later, I'll add the germ. for now - I need to learn what technologies are available).
    I want to be able to describe for an engineer exactly what to build.
    What are the technology disabilities, power consumption, capabilities. How to control it - can it be done automatically? I probably need it small, very small.

    Intuition - it's like a tube of an inkjet, that will shoot a liquid drops, and then a matching plate to collect them, and control their flow to a location at my desire.
    Thanks everybody for your help.
    Hanan.
     
  8. Dec 14, 2005 #7

    Q_Goest

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    Hi hananl, welcome to the board. I really don't have any experience in extreamly small fluid system design such as what you're suggesting, but if I had a project such as yours I might start getting some ideas about what is available in industry that I could make a system out of.

    Many years ago I came across a company called Lee that makes miniture valves. I'm sure there are many others, but you might start looking through their web page first to get some ideas about what kind of valves are available. They also have their own method of fluid flow analysis which you might be interested in.

    I can't vouch for the company, I've never used them or heard of their use before but they seem quite professional and they're still in business after many years so they must be doing something right.
     
  9. Dec 14, 2005 #8

    Danger

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    SciAm to the rescue again... I think. Now that I have a better idea of what you want to do, there's something that might be exactly right for you. Again, I'll have to try finding it.
    A few months ago (again, I'm not sure exactly), there was a feature about student achievement awards. One winner was a lad who had modified some pre-existing device to manage fluid transport on a nano scale. I think that it was some sort of induced capillary action or such-like. The action seemed reminiscent of gel electrophoresis, except that the liquid was confined to channels.
     
  10. Dec 14, 2005 #9
    article

    Thanks danger,
    I am sure waiting for this article you are talking about.
    I hope, it "exactly what you need" as you said...
    Thanks for your efforts,
    Hanan.
     
  11. Dec 14, 2005 #10
    lee products

    Thanks goest,
    It seems like they are very proffesional, and might give me ideas for the project.
    Hanan.
     
  12. Dec 14, 2005 #11

    Danger

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    Okay, pal... I think I found it. The February '05 issue has a feature called 'The New College Try'. Although I can't read it on-line without a subscription, and have no bloody idea where about my maelstrom of a house the original copy is, I'm pretty sure that it's the one I was talking about.
     
  13. Dec 14, 2005 #12

    FredGarvin

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    Lee plugs are the best. They are used in so many places in aviation that you couldn't imagine. I mainly see them in actuators, but you see them in a lot of other places like fuel controls. They also make metering orifices and jets. I can't imagine that their products are on the size scale being considered.

    Lee's LOHM (liquid ohms) system is pretty good. It's easy to work with.
     
  14. Dec 14, 2005 #13

    Q_Goest

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    Hey Fred. Interesting, I'd have never thought they were used for something as large as aircraft hydraulics. I had their catalog long ago but nothing in there seemed big enough and I've used components as small as 1/4" tube size. I guess they must have some larger stuff if you've used them in aircraft though. I've also never tried the liquid ohms thing they came up with, probably a predjudice for the mainstream analysis.

    There's an interesting web page that shows some of their stuff here.

    It includes tubing down to 0.062" OD, micro dispencers for drops as small as ink jet printer drops, pumps down to 50 micro liters per stroke, and all sorts of other control valves, both electric and non.
     
  15. Dec 14, 2005 #14

    FredGarvin

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    Q,
    You would be surprised. Actuators have some pretty small passages in them. I can think of a couple off the top of my head where the Lee plug was about 3/16" in diameter. I'll see if I can't dig up some photos at work tomorrow.

    I sure would like to have the opportunity to work on something that needed one of those little pumps.
     
  16. Dec 14, 2005 #15
    further question

    Hey all,
    Regarding for those questions of mine does anybody knows a way to control the inkjet cartige with pulse signals instead of the computer.
    I want to be able to "shoot" ink droplets from all the nozzles at the same time. I need to know how to operate each of the pizo crystals, and then to operate them all.
    Anyone?
    Thanks,
    Hanan.
     
  17. Dec 14, 2005 #16

    Danger

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    Your PM on that subject is in the mail. It might be best if you copy it and post it here, so that others can give their critiques and suggestions. I don't have time to retype it before logging off.
     
  18. Dec 15, 2005 #17
    found the article

    Hey,
    I found the articel danger was talking about.
    I just downloaded it now, and if you are interested - i attached the doc file here.
    Hanan.
     

    Attached Files:

  19. Dec 18, 2005 #18
    more files - piezo and cytrometer

    if you r interested, i found more interesting articels:
    a file explaining about flowcytrometer.
    a file explaining methods how to switch many piezo electric crystals.

    enjoy,
    Hanan.
     

    Attached Files:

  20. Dec 19, 2005 #19

    FredGarvin

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    Those were some good articles. It amazes me that the cytometer can analyze something in just a couple of microseconds as something is free falling. Pretty cool if you ask me.
     
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