That's interesting about the UV and Blue types of light.
I'll mention a few notes just in case you havent thought of these things yet...
if you have then this will be a bit boring to read
but i have no way
of knowing without asking first.
1. Shouldnt you experiment with the quantitative light effect on the bacteria first,
before moving to the design phase, or are you already very confident that this will
work to some degree which will be beneficial?
2. Any LEDs that draw 250ma are going to dissipate a significant amount of
heat. If that heat is not dissipated somewhere the temperature builds up
almost endlessly. I would have to ask therefore what are the heat dissipation
qualities of the human throat, in the exact place you plan to insert this,
or alternately, have you a plan to get rid of this heat?
This aspect of the design depends highly on the outcome of #1 above
because #1 will set the designs target light output which will pretty
much dictate the total heat output that has to be dealt with.
250ma x 3.3v equals 825 milliwatts, a very significant source of heat when
in a confined area. If this were a regular LED design, i would say a 0.825
square inch surface area would dissipate the heat while raising the surface
temperature by about 60 degrees C (acceptable for many solid state devices).
This isnt something you would want to keep your finger on however.
The heat from one smaller LED isnt as bad of course, but for a more significant
amount of light you would need more of these LEDs, and more LEDs put out
3. LED lumen maintenance is an issue when running the same LED
for hours on end. The only way to combat this is to perform periodic
tests or, better yet, build in some feedback to trigger an alarm when
the light output decreases to a level which is no longer considered
I have worked with something similar to conductive epoxy (i assume you mean
electrically conductive rather than thermally conductive). I have to say that
i was surprised by the results, in that the stuff was at least usable, and i was
able to get a rough idea of the resistivity and go from there. It wasnt great
but it was at least usable when soldering isnt going to work.
One note here however is that the resistivity varies *greatly* from product
to product, and so definitely have to check this before buying. Also a
surprise, the resistivity does not necessarily go down with cost, so
a review of the specs is a must. The application technique also varies
the conductivity somewhat too, so the application technique should be
practiced and applied exactly the same way each time, using the same
Also, a little experimentation before use to make sure the specs are as
they say they are.
I can not comment on the strength however, because the stuff i used was a
very economy version and it didnt even have an epoxy base, but one thing
that helps any 'connection' made with any material like this is the
application of a second coat of some other material that acts as a
protection layer as well as to add strength to the finished joint.
For my needs, i could apply a thick coat of regulator ol' five minute
epoxy and that was all it needed. For your use, you might have to find
a more non toxic material, which im betting you looked into already.
I hope some of this helped, and i wouldnt mind hearing how the whole
thing worked out in the end.
I know this was a little long, so here's a recap of the main points:
1. Quantitative light vs bacteria study / equation
2. Heat dissipation qualities inside the throat; ways to combat
3. Pros and cons of electrically conductive epoxy; strengthening; toxicity; quality testing
4. LED lumen maintenance considerations.