
Replacing $100K diagnostic chip fab with Shrinky-Dinks and a laser-printer - andrewbadera
http://www.boingboing.net/2009/11/08/replacing-100k-diagn.html
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aarongough
Topic background info links (for others like me that had no idea what
Microfluidics entailed):

<http://en.wikipedia.org/wiki/Microfluidics>

<http://en.wikipedia.org/wiki/Shrinky_Dinks>

<http://en.wikipedia.org/wiki/DNA_microarray>

<http://en.wikipedia.org/wiki/Lab-on-a-chip>

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regularfry
Anyone know what scale factor shrinkage you get out of this stuff? I'd quite
like to experiment with optical effects, but I don't know what feature size
you can get and I haven't got any expanded polystyrene handy for testing.

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aarongough
_"When heated in an oven or with a heat gun, the plastic shrinks by about
5/8ths and becomes thicker and more rigid, while retaining the colored
design."_

<http://en.wikipedia.org/wiki/Shrinky_Dinks>

Seems like you would be able to get pretty small feature sizes if you had a
really high resolution printer to begin with...

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regularfry
It surprises me that 5/8ths is enough of a difference to be useful, but then I
guess it's the way it bunches and forms a ridge that's important for the
microfluidics, not the absolute feature size. Hm.

~~~
aarongough
It didn't strike me that 5/8ths wasn't actually a huge amount until I thought
about it.

If the ability to form troughs/ridges is the important thing then I think that
the PCB etch/make mold technique would be just as useful. But I'm not sure
what the smallest feature size is that you can make with this method:

PCB etch/make mold method:

Laser-print an inverse pattern mask on clear plastic film

Expose a UV sensitive photoresist PCB using the mask

Etch the PCB

Make a polymer mold (or mold the final part) using the troughs/ridges formed
by the etched/unetched copper on the PCB

I know this method has been used for replicating fingerprint patterns in the
past (Mythbusters!) and I remember hearing it being used for a few other
things...

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duh
The dearth of women in software development and the preponderance of women in
biotechnology are probably not unrelated phenomena.

~~~
MikeCapone
What is the link that you see?

~~~
duh
I don't see one, but that doesn't mean it doesn't exist.

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michael_dorfman
Now _that's_ an impressive hack. You, Madam, win the internets.

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blhack
In case you're wondering, I think you're being downmodded for using the term
"internets".

(It drives me nuts that when people downvote you, but don't give an
explanation)

Given your karma and how long you've been here, you should know better! FOR
SHAME!

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josefresco
No he got downmodded because his comment didn't add to the conversation. One-
line, humorous comments with no meat are generally frowned upon and become
easy targets.

~~~
allenp
Additionally, this comment is fairly reddit-esque so I'm guessing there is
even more incentive to kill it before it goes any further.

~~~
teeja
On Slashdot that would qualify as a 4 "Funny"

