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How to generate micro-waves for engineering project?

  1. Sep 7, 2012 #1
    Hi All,

    So i have to do a small engineering project, and i am wondering how to generate micro-waves. The goal of our project is to design a bracelet that can remotely activated to break a gelatin capsule embedded inside the capsule and will release a sedative (which will be absorbed through the skin). So what i was thinking is that i have a small microwave generating source that will will heat up the water inside the gelatin capsule, that will in turn destroy the capsule. However i have no idea on how to go about doing this. (first time engineering project, and it is far out of my comfort zone) So i was wondering if somebody could give a couple of tips/pointers on this. Also, i was wondering if someone could give me some ideas on how to remotely activate this.

    Best Regards,

    Slythecooper
     
  2. jcsd
  3. Sep 7, 2012 #2
    Why not heat the water in the capsule up with resistive/inductive heating instead? That would be a lot simpler I think than a mini wrist-watch microwave. I hope this is not part of a mad scientist super villain plot lol.
     
    Last edited: Sep 7, 2012
  4. Sep 7, 2012 #3

    berkeman

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    Welcome to the PF.

    Besides being dangerous, it would be illegal to do what you are saying. The RF spectrum is regulated by the FCC in the US (and other agencies in other countries), and you can't just fire up the old microwave beam out in the open. There's a reason that microwave ovens are shielded, and microwave RF communication is regulated.

    So I'd encourage you to explore other options for your project. Perhaps some more standard method of communicating with the bracelet (like using licensed RFID communication), with a receiver in the bracelet that dispenses the medication...
     
  5. Sep 7, 2012 #4
    I think you may have misunderstood the goal of the micro waves. They are in sealed inside the bracelet. The microwaves are only in place to break the capsule, not to remotely activate the mechanism. Also, could you please elaborate a bit on the RFID, and perhaps say where i could buy it?
     
  6. Sep 7, 2012 #5
    Lol, no super villain plot. Hmm.. could you explain your idea to me a bit more? im not very good with electronics, and am not quite sure how your idea would work...
     
  7. Sep 7, 2012 #6
    I would definitely wipe any interest in using microwave technology if I were not good with electronics (and even if you are good, it would still be a hard subject to tackle). Most importantly, its dangerous, especially if you don't know what you are doing.


    If your goal is to generate heat on a bracelet, you could simply heat a power resistor or some other component that dissipates heat by passing enough current through it. If it is a one-use thing, you could heat it until it is destroyed and it wouldn't matter.

    see this for more information:
    http://en.wikipedia.org/wiki/Heating_element

    You could also use an electromagnet to move some kind of magnetic needle or piece of metal to cut into your capsule.
     
    Last edited: Sep 7, 2012
  8. Sep 7, 2012 #7

    berkeman

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    How much range do you want this RF activation to have? Are we talking a meter (like from the bedside), a few meters (like within a room or house), or like cell-phone call distance away?

    BTW, there are lots easier ways to dispense gell or liquid than breaking a capsule. You can just use a small micropump mechanism -- that would take lots less battery power than heating up a capsule to break it.
     
  9. Sep 7, 2012 #8
    hmm.. lets say around 25 - 50m ish... Would that be possible?

    What type of micropump mechanism are you specifying. Something like an Osmotic micropump? and how could i possibly get the RFID to activate it?
     
  10. Sep 7, 2012 #9
    I am curious as to how much power i needed for this. Double/triple A, or something smaller? Also, how could i get the RFID, as suggested by [berkeman] to activate it? Yes, this is meant to be disposable..
     
  11. Sep 7, 2012 #10

    berkeman

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    RFID is usually pretty short range, IIRC. to get 25m range, you will need some RF communication standard like BlueTooth or similar. You might want 2-way communication anyway, to acknowledge that the correct dose has been delivered. Non-acknowledged 1-way comm doesn't match well with a biomedical application.
     
  12. Sep 7, 2012 #11
    The aim of the project is to be a prototype for extra prison security. I actually think the RFID thing will work. Instead of being remotely activated like previously thought, i think that i would like to make something that detects if the bracelet is too close to the source (which is stuck on the prison walls). So revise my statement and say that around 3-5 metres is good. Also, i'm fine with 1 way communication. Its only a sedative. but how can i get the RFID receiver to give power to a heating source? This is my main concern...
     
  13. Sep 7, 2012 #12

    berkeman

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    You're going to use a bracelet on the prisoners to tranquilize them if they get too close to something? Why not just shoot them with a tranq dart? :bugeye:
     
  14. Sep 7, 2012 #13
    because the target prisons (in the middle east) have guards that aren't expert snipers. The dart could easily hit something important (eg. head eye). Also, they can quickly take it out, causing the sedative to possible not be inserted properly. Also, its painful. The bracelet is much less painful and will eliminate the chance of being hit in the eye or other places...
     
  15. Sep 7, 2012 #14
    but anyway, any ideas on how contact with the RFID reader could trigger the heating mechanism (see above)
     
  16. Sep 7, 2012 #15

    berkeman

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    Nope. This thread is closed for PF Rules violations. Don't post about this subject here again.
     
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