DIY Microfluidics Device Manufacturing

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scoc...@gmail.com

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Nov 21, 2013, 6:02:54 PM11/21/13
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You guys and gals know of anyone working on micro-cnc designs or Microfluidics channel layout making protocols. Something like resin casting, cnc milling, etc. I had a project on the backburner and wanted to give some chemostat-esque apparatuses (aparati?) a shot. Just got a hankering for making tiny channels in plastic and playing with chemostats. Thanks!
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Nathan McCorkle

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Nov 21, 2013, 6:44:04 PM11/21/13
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I'm building a gear stepper motor controlled 3-point kinematic mount
now for focusing a projected image onto a plane. I've got a DMD/DLP
projector with the focus ring turned past the factory set-screw
projecting 1024 pixels across ~1cm. Its aslso rigged up to a
microcontroller so it thinks the fans are on and running properly
(since I took out the lamp, there are no fans). Now I'm working on
stepper microstepping with an arduino, but can't do any wet-lab until
next month. I got some eBay photoresist for PCBs and got a local
photoresist manufacturer to do some simulations for me to get the
right curved channels with their product. Another thing I'll try is
the dry photoresist films they sell for PCBs, just heard today that
they're likely 50-100 microns thick. Getting curved channels often
requires defocused exposure and some combination of lower-temp/longer
post exposure bake and/or incomplete develepment.

You might also try an 8000 DPI mask from
http://www.laserlab.com/photoplot.php instead of a digital projector
mask, they use a CNC laser to expose the photo-film. Then you could
try contact exposure of the eBay dry films, and use eBay developer
too. Then you'd have your pattern in the film, and could put a glass
slide on top and try it out. If you started with the film on a
copper-clad PCB you could etch a circuit board, or use the etched
copper board (clean off the film first) as a master stamp for pressing
into uncured silicone. Peel off the silicon layer and sandwich between
2 glass slides.

You can also use double-sided sticky tape, a laser cutter, and some
plastic or glass slides. Tape is around 30 or 40 microns thick I
believe, normal stuff works, or they sell engineering-grade tapes with
more chemically resistant/compatible adhesives or bulk plastic.

Often oxygen plasma is used to bond glass and silicones, you can make
a plasma bonder easily with a hand vacuum pump, an oxygen cylinder, a
home food microwave, and some HomeDepot/hardware-store PVC pipe and
rubber gasket sheeting:
Homemade Oxygen Plasma Etcher & PDMS to Glass Bonding Test - Black Box Labs
http://www.youtube.com/watch?v=N-R0_nXpc7I

If you're talking software, get AutoCAD, inventor doesn't work well
with Microns as units... with AutoCAD comes this, though it could
probably be hacked into something open-source:
http://groups.csail.mit.edu/cag/micado/
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Nathan McCorkle

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Nov 21, 2013, 10:29:07 PM11/21/13
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I forgot to mention this regarding the double-sided sticky tape:
https://www.youtube.com/watch?v=igqv5dtiv6g

On Thu, Nov 21, 2013 at 3:02 PM, <scoc...@gmail.com> wrote:
>

John Griessen

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Nov 22, 2013, 10:29:59 AM11/22/13
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On 11/21/2013 05:44 PM, Nathan McCorkle wrote:
> I got some eBay photoresist for PCBs and got a local
> photoresist manufacturer to do some simulations for me to get the
> right curved channels with their product. Another thing I'll try is
> the dry photoresist films they sell for PCBs, just heard today that
> they're likely 50-100 microns thick. Getting curved channels often
> requires defocused exposure and some combination of lower-temp/longer
> post exposure bake and/or incomplete develepment.

What width channels are you aiming for?
Is the defocusing to blur jaggies from the DLP or
are you talking curved in cross section?

If curved in cross section, that is crossways with the intent
of a photomask -- usually that wants "gone where light hits"
so all the way through.

Are you wanting to cut trenches in photoresist instead of make
it "go away all the way through where light hits"?

For that, you could mix some light absorbing dye or pigment in with it
so the exposure light would not go all the way through.

Sebastian Cocioba

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Nov 22, 2013, 1:28:26 PM11/22/13
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Would a sub-$1k laser like this be of use for microfluidics fab a la
acrylic and tape?

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D From: John Griessen
Sent: 11/22/2013 10:30 AM
To: diy...@googlegroups.com
Subject: Re: [DIYbio] DIY Microfluidics Device Manufacturing
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Sebastian Cocioba

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Nov 22, 2013, 1:29:02 PM11/22/13
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http://m.ebay.com/itm?itemId=200988809156

Forgot to link.

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D From: Sebastian Cocioba
Sent: 11/22/2013 1:28 PM
To: diybio
Subject: RE: [DIYbio] DIY Microfluidics Device Manufacturing

Nathan McCorkle

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Nov 22, 2013, 2:04:12 PM11/22/13
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Yep! That's what the cuvette in the video I linked to was made with. Spot size is limited by the CO2 laser's wavelength, 10.6 Microns, but also by how well manufactured the laser tube is within some exact integer value of the wavelength, any imperfect lenses or mirrors or focus adjustment. Average for these desktop laser cutters is 100-500 microns. Focusing is hard because you can't see the beam with your eyes, using a piece of heat sensitive receipt paper is how I've done it, they also sell reusable heat sensitive (liquid crystal filled?) Index card sized things, pretty cheap... Like a 'mood ring' sort of effect.  Having the optical movement axes not perfectly parallel with the build surface could be an issue for larger devices.

On Nov 22, 2013 10:28 AM, "Sebastian Cocioba" <scoc...@gmail.com> wrote:

Dieter

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Nov 22, 2013, 10:08:43 PM11/22/13
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Not all fluidics are created equally. I think you'd have a hard time creating a chemostat with a milled fluidic system. What are you trying to do?

BioBot

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Nov 24, 2013, 9:31:21 PM11/24/13
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Maybe easiler just to print it using 3D printer and use it as a master...
Robo

Nathan McCorkle

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Nov 24, 2013, 10:35:10 PM11/24/13
to diybio, Jordan Miller
On Sun, Nov 24, 2013 at 6:31 PM, BioBot <ccha...@gmail.com> wrote:
> Maybe easiler just to print it using 3D printer and use it as a master...
> Robo

Hmm, you certainly wouldn't be able to get channels closely spaced
together, based on the diameter extruded. Section 3.5 is on FDM (fused
deposition modelling):
http://diyhpl.us/~nmz787/pdf/A_review_on_3D_micro-additive_manufacturing_technologies.pdf

Also, Dr. Jordan Miller would probably be the most experienced here on
the list. I'll cc him.

>
>
> On Friday, November 22, 2013 10:08:43 PM UTC-5, Dieter wrote:
>>
>> Not all fluidics are created equally. I think you'd have a hard time
>> creating a chemostat with a milled fluidic system. What are you trying to
>> do?
>>
>> On Thursday, November 21, 2013 3:02:54 PM UTC-8, Sebastian wrote:
>>>
>>>
>>> You guys and gals know of anyone working on micro-cnc designs or
>>> Microfluidics channel layout making protocols. Something like resin casting,
>>> cnc milling, etc. I had a project on the backburner and wanted to give some
>>> chemostat-esque apparatuses (aparati?) a shot. Just got a hankering for
>>> making tiny channels in plastic and playing with chemostats. Thanks!
>>> Sent from Windows Mail
>>>
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--
-Nathan

Nathan McCorkle

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Nov 24, 2013, 10:47:31 PM11/24/13
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http://envisiontec.com/products/3d-bioplotter/

MakerBot says 2.5 micron Z and 11 micron XY resolution, but I know
most people use 100 micron setting for the Z, so I'm not sure if
anyone has used it at the limit. A quick google doesn't anything much
for 'microfluidics makerbot' (without the quotes).

These caught my eye, but only lead me to the previously posted links.

http://www.reddit.com/r/3Dprinting/comments/1do7pm/recommendations_for_a_high_resolution_3d_printer/
http://www.practicalmachinist.com/vb/general/3d-printing-makerbot-replicator-2-way-could-actually-useful-252817/index3.html
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Sebastian Cocioba

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Nov 25, 2013, 12:56:47 PM11/25/13
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I wanted to mess around with the old shrinky dink-pdms route. End goal
is just a learning experience and potentially something to test
protoplast turgor in real time. Not trying to do anything fancy, thanks
a ton for the huge post and effort, Nathan! It would also be
interesting to stream line small volume plant hormone mixes via
gradient diffusion and use the resulting batch of gradient samples in
protoplast growth and regeneration experiments. Time to dig up ye olde
shrinky dink kit. :P Shooting for semi-micro fluidics on the order of
tens to hundreds of uL and cells roughly 50um in diameter.

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D From: Nathan McCorkle
Sent: 11/24/2013 10:47 PM
To: diybio
Subject: Re: [DIYbio] Re: DIY Microfluidics Device Manufacturing
https://groups.google.com/d/msgid/diybio/CA%2B82U9%2B3aJpTrQX2YE16p0_%2B_Pn8Ua1y_Z1FDZjc4KRuqb9cvA%40mail.gmail.com.
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