Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

My co-worker has a formlabs printer, it seems pretty decent... The Z
direction sounds good, but I imagine it could be obviated by the use
of a spin-coater. They say their minimum feature size if 300microns...
I was thinking about this recently actually and ran into the
laserShark galvanometer controller. I think the main thing that would
need to change for great microfluidics with this type of setup is
really just the per-bit voltage-interval... i.e. if the DAC on the
galvanometer controller is 16-bits spanning the form1 build dimensions
of "125 × 125 × 165 mm"... then the range of millimeters spanned needs
decreased. If it's a linear decrease, then if I wanted a max
microfluidic X/Y dimension of 30mm, that's 125/30==4.166 then
300/4.166==72 microns resolution. Maybe their DAC is not enough bits,
or maybe this technique is not optimal, I don't know. It could simply
be that the long path that the beam passes takes, leaving the laser,
bouncing off the galvos, is just too much from a beam divergence
standpoint. To get a small spot size with such focal distances, I
think the laser would need a pretty big beam expander before lensing
onto the first galvo.

On Sat, Feb 28, 2015 at 3:52 PM, Otto Heringer <ottowheringer@gmail.com> wrote:
> I always wanted to print a mold for PDMS microfluidic chips using a "form 1"
> 3D printer (that one who got funded on kickstarter). They say that it have
> 10 microns of resolution on Z axis.
>
> When I was about to try it on a local FAB Lab, the printer got broke! If it
> was worked out, I would suggest to consider a 3D printer for the molds.
>
> I think its about time for people go for digital fabrication methods on
> microfluidics.
>
> Em 27/02/2015 21:17, <scocioba@gmail.com> escreveu:
>
>> This is true, only issue there was when using a syringe to pull from chip
>> to chip, the line would sputter and induce air pockets on top of very swift
>> changes in fluid flow once it gets past the bottleneck that is the chip.
>> There is a lot of resistance since the channel features are so small that
>> manual pull is to quick. Need a syringe pump in reverse that pulls slowly.
>>
>> Like filling a syringe quickly with liquid through a very small needle, it
>> bucks back until the liquid meets the top of the plunger (vacuum until
>> pressure equalizes) so either way fine, non-manual control would be ideal.
>> Backpressure is too high for standard cheap-o eBay peristaltic pumps in
>> either direction. Basically its analogous to electronic theory...small
>> channel, high resistance. Syringe acts as a voltage source trying to pull
>> more than the channel can deliver so its either slow or the channels (or
>> chip) fails structurally.
>>
>> For the few moments when the pdms is perfectly bonded via coronal arch
>> discharge and everything is aligned properly, I did get some plant
>> protoplasts stuck in a T junction for a while while flowing media through.
>> Its possible, just really really finicky.
>>
>> On my laundry list of experiments to run, I'd like to do some data
>> gathering on the characteristics of shrinky dink plastic sheets,
>> temperature, shrink rate (~63%), etc to see if its a viable material for
>> making multiple fairly-identical chips. Basically a datasheet characterizing
>> the material within the scope of microfluidics. May prove useful to people
>> trying to start working with microfluidics.
>>
>> Sebastian S. Cocioba
>> CEO & Founder
>> New York Botanics, LLC
>> Plant Biotech R&D
>> ________________________________
>> From: John Griessen
>> Sent: ‎2/‎27/‎2015 6:46 PM
>> To: diybio@googlegroups.com
>> Subject: Re: [DIYbio] Re: At home fabrication of micron scale
>> microfluidics
>>
>> On 02/27/2015 05:29 PM, Simon Quellen Field wrote:
>> > The alternative that suggests itself is to pull the liquid from one
>> > block to another using a relative vacuum. Now the liquid wants
>> > to go only where you want it to go.
>>
>> because vacuum makes contact seals seal harder, and pressure makes them
>> leak.
>>
>> --
>> -- You received this message because you are subscribed to the Google
>> Groups DIYbio group. To post to this group, send email to
>> diybio@googlegroups.com. To unsubscribe from this group, send email to
>> diybio+unsubscribe@googlegroups.com. For more options, visit this group at
>> https://groups.google.com/d/forum/diybio?hl=en
>> Learn more at www.diybio.org
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "DIYbio" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to diybio+unsubscribe@googlegroups.com.
>> To post to this group, send email to diybio@googlegroups.com.
>> Visit this group at http://groups.google.com/group/diybio.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/diybio/54F102BA.3090401%40industromatic.com.
>> For more options, visit https://groups.google.com/d/optout.
>>
>> --
>> -- You received this message because you are subscribed to the Google
>> Groups DIYbio group. To post to this group, send email to
>> diybio@googlegroups.com. To unsubscribe from this group, send email to
>> diybio+unsubscribe@googlegroups.com. For more options, visit this group at
>> https://groups.google.com/d/forum/diybio?hl=en
>> Learn more at www.diybio.org
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "DIYbio" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to diybio+unsubscribe@googlegroups.com.
>> To post to this group, send email to diybio@googlegroups.com.
>> Visit this group at http://groups.google.com/group/diybio.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/diybio/54f108f9.8157e00a.41bc.0d18%40mx.google.com.
>> For more options, visit https://groups.google.com/d/optout.
>
> --
> -- You received this message because you are subscribed to the Google Groups
> DIYbio group. To post to this group, send email to diybio@googlegroups.com.
> To unsubscribe from this group, send email to
> diybio+unsubscribe@googlegroups.com. For more options, visit this group at
> https://groups.google.com/d/forum/diybio?hl=en
> Learn more at www.diybio.org
> ---
> You received this message because you are subscribed to the Google Groups
> "DIYbio" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to diybio+unsubscribe@googlegroups.com.
> To post to this group, send email to diybio@googlegroups.com.
> Visit this group at http://groups.google.com/group/diybio.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/diybio/CAB%3DC6ZJjwZrt0LUVdhQQTA-s69adh9UbFjmVGLnH0MvSs2Zvnw%40mail.gmail.com.
>
> For more options, visit https://groups.google.com/d/optout.



--
-Nathan

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CA%2B82U9%2BVQwrvu2PUbewHiDgnhnYfFL4Lq9Um%3DG20MiwnaN6OBQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

RE: [DIYbio] Re: At home fabrication of micron scale microfluidics

I always wanted to print a mold for PDMS microfluidic chips using a "form 1" 3D printer (that one who got funded on kickstarter). They say that it have 10 microns of resolution on Z axis.

When I was about to try it on a local FAB Lab, the printer got broke! If it was worked out, I would suggest to consider a 3D printer for the molds.

I think its about time for people go for digital fabrication methods on microfluidics.

Em 27/02/2015 21:17, <scocioba@gmail.com> escreveu:
This is true, only issue there was when using a syringe to pull from chip to chip, the line would sputter and induce air pockets on top of very swift changes in fluid flow once it gets past the bottleneck that is the chip. There is a lot of resistance since the channel features are so small that manual pull is to quick. Need a syringe pump in reverse that pulls slowly.

Like filling a syringe quickly with liquid through a very small needle, it bucks back until the liquid meets the top of the plunger (vacuum until pressure equalizes) so either way fine, non-manual control would be ideal. Backpressure is too high for standard cheap-o eBay peristaltic pumps in either direction. Basically its analogous to electronic theory...small channel, high resistance. Syringe acts as a voltage source trying to pull more than the channel can deliver so its either slow or the channels (or chip) fails structurally.

For the few moments when the pdms is perfectly bonded via coronal arch discharge and everything is aligned properly, I did get some plant protoplasts stuck in a T junction for a while while flowing media through. Its possible, just really really finicky.

On my laundry list of experiments to run, I'd like to do some data gathering on the characteristics of shrinky dink plastic sheets, temperature, shrink rate (~63%), etc to see if its a viable material for making multiple fairly-identical chips. Basically a datasheet characterizing the material within the scope of microfluidics. May prove useful to people trying to start working with microfluidics.

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D

From: John Griessen
Sent: ‎2/‎27/‎2015 6:46 PM
To: diybio@googlegroups.com
Subject: Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

On 02/27/2015 05:29 PM, Simon Quellen Field wrote:
> The alternative that suggests itself is to pull the liquid from one block to another using a relative vacuum. Now the liquid wants
> to go only where you want it to go.

because vacuum makes contact seals seal harder, and pressure makes them leak.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F102BA.3090401%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54f108f9.8157e00a.41bc.0d18%40mx.google.com.
For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CAB%3DC6ZJjwZrt0LUVdhQQTA-s69adh9UbFjmVGLnH0MvSs2Zvnw%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

[DIYbio] Re: At home fabrication of micron scale microfluidics

If you don't need microvalves, there is some interesting work being done with low cost laminate microfluidics. The general idea is to laminate together transparencies printed in a laser printer. The toner can act as thermally set glue and thin channels, and thicker channels can be defined via laser cutting. This is low cost, requires reasonably cheap equipment, and uses no wet processes.

 http://diyhpl.us/~bryan/papers2/microfluidics/A%20Dry%20Process%20for%20Production%20of%20Microfluidic%20Devices%20Based%20on%20the%20Lamination%20of%20Laser-Printed%20Polyester%20Films.pdf (Bryan Bishop strikes again)




On Friday, February 27, 2015 at 5:42:56 AM UTC-8, Peter Shankles wrote:
Hello all,

I'm new to the DIYbio community and need your perspective on something. 

I'm working on a project that would make microfluidics available to use at home. Because I'm working on this at a national lab, I can't give too many specifics at this time. With that being said our setup would include software for designing devices and creating a master mold for soft lithography. The resolution would be on the order of 100 um, and the fabrication time would be a couple of hours. 

What I want to know is:
  What types of features and designs would be most important to include?
  How much would you be willing to pay for this functionality (software will be open source, but there is hardware as well)?
  What would you be most interested in using microfluidics for?
  Anything else you can think of. I would appreciate any input you have.

Thanks for your time,
Peter

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/ffc3ebcf-feed-4cc4-beb5-688348691444%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: evaporation losses... was: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

The two terms xs and x are temperature based terms relating temperature to how much the air can absorb.... Something like that.

On Feb 28, 2015 7:18 AM, "John Griessen" <john@industromatic.com> wrote:
On 02/28/2015 03:57 AM, Nathan McCorkle wrote:
perhaps hone the
calculation to get rid of my 'mollier diagram; guesstimation issues?

I did not see temperature in the model, so it seems odd to miss that...

or is it there as a worst case constant somewhere at about 40 deg C?

As evaporation happens from a capillary, the exposed water surface will shrink back into
the capillary and cause evap slow down more because it is in a well where there will be no breeze.

That part seems to become a diffusion calculation that will vary as depth of the "well".

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
--- You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F1DD42.5080405%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CA%2B82U9Jwb2dHUmoLqNAeip5GLRSpoSrBsa0raMdcBi5sx-oEtQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: evaporation losses... was: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

On 02/28/2015 03:57 AM, Nathan McCorkle wrote:
> perhaps hone the
>>calculation to get rid of my 'mollier diagram; guesstimation issues?

I did not see temperature in the model, so it seems odd to miss that...

or is it there as a worst case constant somewhere at about 40 deg C?

As evaporation happens from a capillary, the exposed water surface will shrink back into
the capillary and cause evap slow down more because it is in a well where there will be no breeze.

That part seems to become a diffusion calculation that will vary as depth of the "well".

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F1DD42.5080405%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: evaporation losses... was: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

There was also this answer, which gives a formula if you know the
energy of your heat source:
http://physics.stackexchange.com/questions/91810/how-do-i-predict-volume-loss-due-to-evaporation-when-boiling-water

On Sat, Feb 28, 2015 at 1:51 AM, Nathan McCorkle <nmz787@gmail.com> wrote:
> On Fri, Feb 27, 2015 at 10:08 PM, Mac Cowell <mac@diybio.org> wrote:
>> The capillary design is not as complicated as you make it sound, Cathal. I
>> think evaporation is marginal in open 10 uL tubes, so they don't need to be
>> closed,
>
>
> hmm, this comment really interested me, since I've previously done
> some experiments where I watched evaporation over a few days using a
> nice mettler lab scale with a serial port on it for data collection.
>
> I tried finding out how to calculate for evaporation losses, and found
> an empirical equation for things like swimming pools.
>
> TLDR; the calculation I did (which could be wrong) shows about 2 to 15
> nanoliters PER HOUR of evaporation for a 100 micron diameter capillary
> with no air movement from 25 to ~65 C (but if you're really
> interested, please try to verify this number on your own... and let us
> know). However, if you increase the diameter from 100 microns to 1mm,
> the evaporation seems to be more like 200nL/H to 1.5uL/H (1500nL/H).
>
>
> This is where I got the equation:
> http://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html
>
> which says:
>
> gs = Θ A (xs - x) / 3600
>
> or
>
> gh = Θ A (xs - x)
>
> where
>
> gs = amount of evaporated water per second (kg/s)
>
> gh = amount of evaporated water per hour (kg/h)
>
> Θ = (25 + 19 v) = evaporation coefficient (kg/m2h)
>
> v = velocity of air above the water surface (m/s)
>
> A = water surface area (m2)
>
> xs = humidity ratio in saturated air at the same temperature as the
> water surface (kg/kg) (kg H2O in kg Dry Air)
>
> x = humidity ratio in the air (kg/kg) (kg H2O in kg Dry Air)
>
>
> What I ended up plugging in for numbers, to get my nanoliter values:
> http://www.wolframalpha.com/input/?i=%2825*%28+pi*%2850+%2F1000000%29%5E2%29*%280.02-0.0098%29%29+kilograms+water+to+microliters
>
>
> used this page to try getting some values to plug in for [xs]
> http://www.engineeringtoolbox.com/humidity-ratio-air-d_686.html
>
> Used this hard-to-figure-out chart to try some other values for a
> higher temperature (variable [x]):
> http://www.engineeringtoolbox.com/psychrometric-chart-mollier-d_27.html
>
>
>
>
>
> Can someone verify or disprove the numbers, or perhaps hone the
> calculation to get rid of my 'mollier diagram; guesstimation issues?



--
-Nathan

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CA%2B82U9KZ9j7sfN%3DsB-RnKTRV9S1zSY7OwwYwdpSBw_ZifcLwFQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

evaporation losses... was: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

On Fri, Feb 27, 2015 at 10:08 PM, Mac Cowell <mac@diybio.org> wrote:
> The capillary design is not as complicated as you make it sound, Cathal. I
> think evaporation is marginal in open 10 uL tubes, so they don't need to be
> closed,


hmm, this comment really interested me, since I've previously done
some experiments where I watched evaporation over a few days using a
nice mettler lab scale with a serial port on it for data collection.

I tried finding out how to calculate for evaporation losses, and found
an empirical equation for things like swimming pools.

TLDR; the calculation I did (which could be wrong) shows about 2 to 15
nanoliters PER HOUR of evaporation for a 100 micron diameter capillary
with no air movement from 25 to ~65 C (but if you're really
interested, please try to verify this number on your own... and let us
know). However, if you increase the diameter from 100 microns to 1mm,
the evaporation seems to be more like 200nL/H to 1.5uL/H (1500nL/H).


This is where I got the equation:
http://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html

which says:

gs = Θ A (xs - x) / 3600

or

gh = Θ A (xs - x)

where

gs = amount of evaporated water per second (kg/s)

gh = amount of evaporated water per hour (kg/h)

Θ = (25 + 19 v) = evaporation coefficient (kg/m2h)

v = velocity of air above the water surface (m/s)

A = water surface area (m2)

xs = humidity ratio in saturated air at the same temperature as the
water surface (kg/kg) (kg H2O in kg Dry Air)

x = humidity ratio in the air (kg/kg) (kg H2O in kg Dry Air)


What I ended up plugging in for numbers, to get my nanoliter values:
http://www.wolframalpha.com/input/?i=%2825*%28+pi*%2850+%2F1000000%29%5E2%29*%280.02-0.0098%29%29+kilograms+water+to+microliters


used this page to try getting some values to plug in for [xs]
http://www.engineeringtoolbox.com/humidity-ratio-air-d_686.html

Used this hard-to-figure-out chart to try some other values for a
higher temperature (variable [x]):
http://www.engineeringtoolbox.com/psychrometric-chart-mollier-d_27.html





Can someone verify or disprove the numbers, or perhaps hone the
calculation to get rid of my 'mollier diagram; guesstimation issues?

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CA%2B82U9KEK-0qaxvPyuYJeUk-JePnXnjZcjwnkyKJPPiMgJ_3Lw%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

The capillary design is not as complicated as you make it sound, Cathal. I think evaporation is marginal in open 10 uL tubes, so they don't need to be closed, and if the peltier is ONLY connected to a heatsink, the thermal mass vs surface area ratio is actually really good even without more radiative or active cooling.

Perhaps the conductivity could be enhanced by heating plastic capillaries to 70 C in the sawtooth heatsink and placing temporary pressure on another inverted sawtooth heatsink from above, to force the tubes to confom into a triangular prism sharing more contact area with the bottom groove of the thermocycled heatsink.

Seriously, not many parts needed...

On Fri, Feb 27, 2015 at 6:33 AM, Cathal Garvey <cathalgarvey@cathalgarvey.me> wrote:
Oh, nice idea! I wonder if even plastic capillaries at that scale are conductive enough to work, I could see it being possible to make "pinch-off" capillaries that you fill (by capillary action? :)) and pinch, then lay on your micro-cycler made with a peltier, two heatsinks, an LM35 temp sensor, and an Arduino micro or similar.

As usual with Peltiers, the big ask is current, so the complexity arises from ensuring enough is delivered from a suitable power source through the peltiers.

I wonder if a "constant heat flow" design couldn't be knocked together with a heating element atop the fins on the reaction side, so heat is conducted downwards through the fins to the tubes, and cooling is achieved by ceasing to apply heat and letting the heatsink distribute what remains. But, that's only marginally simpler than fixing up a cooling fan to a simple heat-block anyway and just doing coil-heating-air-cooling, which is possibly as efficient as these things get until you start coming full-circle to convective PCR (pun welcomed but not intended)..

On 27/02/15 08:35, Mac Cowell wrote:
Also, just want to point out that if you fill capillary glass tranfer
pipettes (typically like $20 for 100, with volumes selectable from
0.5-50uL), they fit perfectly in the valleys of many
sawtooth-style sinks (cheap). The surface to volume ratio is such that I
don't think a heated lid is necessary.  Imaging from above is possible,
potentially enabling qpcr-like applications.

They are just a bit of a pain to work with.

But the thermocycler is so simple in this case. Peltier, sawtooth heat
sink with 5-10 ridges, mosfet for switching power, embedded
thermocouple, microcontroller, and 5-10 glass capillaries, one per sample.

Cheers
Mac

On Friday, February 27, 2015, Mac Cowell <mac@diybio.org
<mailto:mac@diybio.org>> wrote:

    The reaction mixture will condense on the coldest part of the pcr
    tube, for instance, any surface not enclosed in the main heated
    block and exposed to ambient air.

    One solution is to establish a temperature gradient from the top of
    the cap to the block by touching the cap with a second hot surface,
    preferably hotter than the main block such radiative and conductive
    heat transfer from the heated lid raises the temperature of all
    surfaces of the pcr tube exposed to air above the current
    temperature of the block.

    But you don't need s Peltier to do this. You just need a heat source
    you can keep at a constant temperature guaranteed to be hotter than
    any of the pcr temps.

    It would be interesting to explore a hybrid design combining
    dynamic conductive heating in the tube block with constant radiative
    heating from a lamp or hot air flow positioned at just the right
    distance, instead of a heated lid in constant contact with the cap.
    Can the radiative heat source be set up to always add +20C to the
    exposed cap and 5-10 C to the reaction mixture? If so, perhaps such
    a design could lead to faster ramp times, by switching the radiator
    off during cooling.

    Does the transparent plastic most pcr tubes are made from absorb IR?

    Or maybe all that matters is if the reaction mixture absorbs the
    radiative energy. Not sure. Would pcr work in a transparent Quartz
    vessel in a freezer that was pulsed by a powerful IR source? Or
    would that be condensation city?

    Cheers
    Mac

    On Thursday, February 26, 2015, Andy Morgan
    <andrew.r.morgan@gmail.com
    <javascript:_e(%7B%7D,'cvml','andrew.r.morgan@gmail.com');>> wrote:

        Thanks for the heads up Josiah.

        That's a bit annoying, I was hoping that I could have the lid at
        the same temperature as the tubes, allowing me to run the whole
        thing off of just the one simple circuit described in the
        original instructable.

        Perhaps I'll look into using one peltier element for the base
        and another smaller one for the lid, although that might mean
        I'd have to hook up a whole other arduino board and solid state
        relay. Not to mention that all sounding a wee bit over my head.
        If I could hook them both up to the one arduino board that might
        be a little bit simpler though.

        I came across this design
        (http://2013.igem.org/Team:Paris_Saclay/PS-PCR/detailed_description)
        that was build (and apparently for only 30 euros!) using peltier
        elements, but the electronic schematics look intense.

        On Friday, February 27, 2015 at 2:12:14 PM UTC+13, Josiah Zayner
        wrote:

            Keeping the lid at a constant temp of ~90C will generally
            suffice. Most PCR machines hold the lid at 90C - 105C.

            I have tried doing the lid at same temperature as the tubes
            but received condensation. I think this might have been
            because of the different heat transfer rates? Maybe you can
            figure it out?

            Looking on eBay these days you can buy most of the parts for
            the Arduino thermalcycler for much cheaper than the $85USD
            pricetag (inexpensive Arduino boards &c). Also, keep on eye
            out on eBay for thermal cyclers. Sometimes people don't know
            what the actual equipment is so they just list it as brand
            and product names so searching directly for brand names
            help. I have found some for under $100 that work great
            though this is from the US, so who knows what you might find?



            Josiah




            On Thursday, February 26, 2015 at 3:02:09 PM UTC-8, Andy
            Morgan wrote:

                Ah it all becomes clear, I was wondering why they listed
                a 12V power supply AND a regular power cable.

                Thanks Simon.

                On Friday, February 27, 2015 at 8:22:16 AM UTC+13, Simon
                Field wrote:

                    I presume the power supply is simply for the Arduino
                    part of the project, which is unchanged from the
                    original. In fact, the only thing that has changed
                    is the heater. It's like swapping a 40 watt light
                    bulb for a 100 watt light bulb. You don't have to
                    change anything else.

                    -----
                    Get a free science project every week!
                    "http://scitoys.com/__newsletter.html
                    <http://scitoys.com/newsletter.html>"

        --
        -- You received this message because you are subscribed to the
        Google Groups DIYbio group. To post to this group, send email to
        diybio@googlegroups.com. To unsubscribe from this group, send
        email to diybio+unsubscribe@googlegroups.com. For more options,
        visit this group at https://groups.google.com/d/forum/diybio?hl=en
        Learn more at www.diybio.org <http://www.diybio.org>
        ---
        You received this message because you are subscribed to the
        Google Groups "DIYbio" group.
        To unsubscribe from this group and stop receiving emails from
        it, send an email to diybio+unsubscribe@googlegroups.com.
        To post to this group, send email to diybio@googlegroups.com.
        Visit this group at http://groups.google.com/group/diybio.
        To view this discussion on the web visit
        https://groups.google.com/d/msgid/diybio/ba876564-210f-4558-8968-78c096bb5d2f%40googlegroups.com
        <https://groups.google.com/d/msgid/diybio/ba876564-210f-4558-8968-78c096bb5d2f%40googlegroups.com?utm_medium=email&utm_source=footer>.
        For more options, visit https://groups.google.com/d/optout.



    --
    Sent from my Rotary Phone



--
Sent from my Rotary Phone

--
-- You received this message because you are subscribed to the Google
Groups DIYbio group. To post to this group, send email to
diybio@googlegroups.com. To unsubscribe from this group, send email to
diybio+unsubscribe@googlegroups.com. For more options, visit this group
at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google
Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to diybio+unsubscribe@googlegroups.com
<mailto:diybio+unsubscribe@googlegroups.com>.
To post to this group, send email to diybio@googlegroups.com
<mailto:diybio@googlegroups.com>.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit
https://groups.google.com/d/msgid/diybio/CA%2BiLdW20HpSQ08Zo1kKnojYSC%2BGhYF_cG%2BkAziQ7kMkKxncoog%40mail.gmail.com
<https://groups.google.com/d/msgid/diybio/CA%2BiLdW20HpSQ08Zo1kKnojYSC%2BGhYF_cG%2BkAziQ7kMkKxncoog%40mail.gmail.com?utm_medium=email&utm_source=footer>.
For more options, visit https://groups.google.com/d/optout.

--
Scientific Director, IndieBio Irish Programme
 Got a biology-inspired business idea that $50,000 -
 & 3 months in a well equipped lab could accelerate?
 Apply for the Summer programme in Ireland:
 http://indie.bio/apply-to-ireland
Twitter:  @onetruecathal
Phone: +353876363185
miniLock: JjmYYngs7akLZUjkvFkuYdsZ3PyPHSZRBKNm6qTYKZfAM
peerio.com: cathalgarvey

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
--- You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F05616.9020302%40cathalgarvey.me.

For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CA%2BiLdW3%2BusCVvWzv1e%2Bm3TjUum1Oc0KQQG_tDshGXRdTy0wDyQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

Not sure it works but a couple of ideas:

1.to reduce the pump pressure of your pump, can you make a T with tubing so one line has much smaller resistance than your chip?
2. Alignment can be a tedious problem, maybe use microscope and a micrometer stage ( http://www.thorlabs.com/navigation.cfm?guide_id=2 ). One chip fixed, other has a 3D control. I used the one on the microscope so I can see and position at the same time.

Yup, it is tricky either way. How did you bind pdms?

On Friday, February 27, 2015 at 6:17:07 PM UTC-6, Sebastian wrote:
This is true, only issue there was when using a syringe to pull from chip to chip, the line would sputter and induce air pockets on top of very swift changes in fluid flow once it gets past the bottleneck that is the chip. There is a lot of resistance since the channel features are so small that manual pull is to quick. Need a syringe pump in reverse that pulls slowly.

Like filling a syringe quickly with liquid through a very small needle, it bucks back until the liquid meets the top of the plunger (vacuum until pressure equalizes) so either way fine, non-manual control would be ideal. Backpressure is too high for standard cheap-o eBay peristaltic pumps in either direction. Basically its analogous to electronic theory...small channel, high resistance. Syringe acts as a voltage source trying to pull more than the channel can deliver so its either slow or the channels (or chip) fails structurally.

For the few moments when the pdms is perfectly bonded via coronal arch discharge and everything is aligned properly, I did get some plant protoplasts stuck in a T junction for a while while flowing media through. Its possible, just really really finicky.

On my laundry list of experiments to run, I'd like to do some data gathering on the characteristics of shrinky dink plastic sheets, temperature, shrink rate (~63%), etc to see if its a viable material for making multiple fairly-identical chips. Basically a datasheet characterizing the material within the scope of microfluidics. May prove useful to people trying to start working with microfluidics.

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D

From: John Griessen
Sent: ‎2/‎27/‎2015 6:46 PM
To: diy...@googlegroups.com
Subject: Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

On 02/27/2015 05:29 PM, Simon Quellen Field wrote:
> The alternative that suggests itself is to pull the liquid from one block to another using a relative vacuum. Now the liquid wants
> to go only where you want it to go.

because vacuum makes contact seals seal harder, and pressure makes them leak.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diy...@googlegroups.com. To unsubscribe from this group, send email to diybio+un...@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+un...@googlegroups.com.
To post to this group, send email to diy...@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F102BA.3090401%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/a5fbfd0f-7ed9-4be4-9ad6-3f3c2f47bbbd%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

RE: [DIYbio] Re: At home fabrication of micron scale microfluidics

This is true, only issue there was when using a syringe to pull from chip to chip, the line would sputter and induce air pockets on top of very swift changes in fluid flow once it gets past the bottleneck that is the chip. There is a lot of resistance since the channel features are so small that manual pull is to quick. Need a syringe pump in reverse that pulls slowly.

Like filling a syringe quickly with liquid through a very small needle, it bucks back until the liquid meets the top of the plunger (vacuum until pressure equalizes) so either way fine, non-manual control would be ideal. Backpressure is too high for standard cheap-o eBay peristaltic pumps in either direction. Basically its analogous to electronic theory...small channel, high resistance. Syringe acts as a voltage source trying to pull more than the channel can deliver so its either slow or the channels (or chip) fails structurally.

For the few moments when the pdms is perfectly bonded via coronal arch discharge and everything is aligned properly, I did get some plant protoplasts stuck in a T junction for a while while flowing media through. Its possible, just really really finicky.

On my laundry list of experiments to run, I'd like to do some data gathering on the characteristics of shrinky dink plastic sheets, temperature, shrink rate (~63%), etc to see if its a viable material for making multiple fairly-identical chips. Basically a datasheet characterizing the material within the scope of microfluidics. May prove useful to people trying to start working with microfluidics.

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D

From: John Griessen
Sent: ‎2/‎27/‎2015 6:46 PM
To: diybio@googlegroups.com
Subject: Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

On 02/27/2015 05:29 PM, Simon Quellen Field wrote:
> The alternative that suggests itself is to pull the liquid from one block to another using a relative vacuum. Now the liquid wants
> to go only where you want it to go.

because vacuum makes contact seals seal harder, and pressure makes them leak.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F102BA.3090401%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

On 02/27/2015 05:29 PM, Simon Quellen Field wrote:
> The alternative that suggests itself is to pull the liquid from one block to another using a relative vacuum. Now the liquid wants
> to go only where you want it to go.

because vacuum makes contact seals seal harder, and pressure makes them leak.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F102BA.3090401%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Re: At home fabrication of micron scale microfluidics

It would seem to me that the main problem in transferring liquid from one block to another is basically the problem of pushing on a rope. The liquid will try to go everywhere except where you want it.

The alternative that suggests itself is to pull the liquid from one block to another using a relative vacuum. Now the liquid wants to go only where you want it to go.


-----
Get a free science project every week! "http://scitoys.com/newsletter.html"


On Fri, Feb 27, 2015 at 3:09 PM, <scocioba@gmail.com> wrote:
I'm my attempts at making modular units, transfer of discrete liquid packets or even continual flow  is tough when you need to move from one chip to another. Alignment, pressure tolerance, hydrophobicity, etc all play a role in getting things up and through.

I tried using tubes as connections and found that slurping and sputtering happens. Aligning chips is a whole other can of grief if you want to make continual modular chips. The Lego based chips seen here:

http://www.redorbit.com/news/science/1113239467/lego-inspired-microfluidics-092214/

Need a very high degree of hole punch, die cutting and overall "machining" to mate well. ShrinkChips are variable during shrink and can lead to small defects. Connecting "millifluidic" chips involving >500um features but at super low volume pressure is an issue. If you don't have a coronal treater or rig a microwave to oxidize the pdms, pressure becomes even more of an issue. I've been spattered with food coloring trying to get a simple 100um T junction working...soooo....yeah. I'm very very interested in alternatives but if the kit is SU-8 at home, I'm out. Its so expensive and the overhead to do it well may be a bit much for the first time lab builder. Just my 2¢...

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D

From: GO
Sent: ‎2/‎27/‎2015 1:22 PM
To: diybio@googlegroups.com
Subject: [DIYbio] Re: At home fabrication of micron scale microfluidics

Can you make lego kind of system? For example, make separate components: channels, valves, chambers with different functions and then sell those? The purpose is that anyone can then assemble a desired system easily since PDMS can be bonded. Otherwise your resolution is my problem and also hydrophobicity of pdms. 
Legos can be easier to sell and manufacture too. I would buy some components for ~$100 but for <20 microns resolution. The purpose would be to embed side electrodes for detection and play with that. 

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/df206d22-90f2-4299-bdac-b9ee6c815bd5%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54f0f91c.36208c0a.3fb0.54ee%40mx.google.com.

For more options, visit https://groups.google.com/d/optout.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CAA0yOM6dZzFd917McYCcCcJ2MgKUdXV92zvkc_WvMz3P5zD0WQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

RE: [DIYbio] Re: At home fabrication of micron scale microfluidics

I'm my attempts at making modular units, transfer of discrete liquid packets or even continual flow  is tough when you need to move from one chip to another. Alignment, pressure tolerance, hydrophobicity, etc all play a role in getting things up and through.

I tried using tubes as connections and found that slurping and sputtering happens. Aligning chips is a whole other can of grief if you want to make continual modular chips. The Lego based chips seen here:

http://www.redorbit.com/news/science/1113239467/lego-inspired-microfluidics-092214/

Need a very high degree of hole punch, die cutting and overall "machining" to mate well. ShrinkChips are variable during shrink and can lead to small defects. Connecting "millifluidic" chips involving >500um features but at super low volume pressure is an issue. If you don't have a coronal treater or rig a microwave to oxidize the pdms, pressure becomes even more of an issue. I've been spattered with food coloring trying to get a simple 100um T junction working...soooo....yeah. I'm very very interested in alternatives but if the kit is SU-8 at home, I'm out. Its so expensive and the overhead to do it well may be a bit much for the first time lab builder. Just my 2¢...

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D

From: GO
Sent: ‎2/‎27/‎2015 1:22 PM
To: diybio@googlegroups.com
Subject: [DIYbio] Re: At home fabrication of micron scale microfluidics

Can you make lego kind of system? For example, make separate components: channels, valves, chambers with different functions and then sell those? The purpose is that anyone can then assemble a desired system easily since PDMS can be bonded. Otherwise your resolution is my problem and also hydrophobicity of pdms. 
Legos can be easier to sell and manufacture too. I would buy some components for ~$100 but for <20 microns resolution. The purpose would be to embed side electrodes for detection and play with that. 

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/df206d22-90f2-4299-bdac-b9ee6c815bd5%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

[DIYbio] Re: At home fabrication of micron scale microfluidics

Can you make lego kind of system? For example, make separate components: channels, valves, chambers with different functions and then sell those? The purpose is that anyone can then assemble a desired system easily since PDMS can be bonded. Otherwise your resolution is my problem and also hydrophobicity of pdms. 
Legos can be easier to sell and manufacture too. I would buy some components for ~$100 but for <20 microns resolution. The purpose would be to embed side electrodes for detection and play with that. 

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/df206d22-90f2-4299-bdac-b9ee6c815bd5%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] At home fabrication of micron scale microfluidics

On Fri, Feb 27, 2015 at 8:59 AM, <scocioba@gmail.com> wrote:
> Would this beat shrinky dink microfluidics? I've managed to make features
> using shrink sheets printed using a standard toner printer and pdms at
> around 100-150um

That was my first thought.... the scale is quite large when you start
thinking of doing cellular operations that are anything more than an
incubation chamber.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CA%2B82U9%2BAHh5y7zGncxhJrUPtT%2BqoJxcOdd21GHfN9oV-5p2NJQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] At home fabrication of micron scale microfluidics

Thus far we have been casting PDMS in thicker slabs. I'll look into possibly adapting it to use with a spinner. Would this be for control valves?
-Peter

On Friday, February 27, 2015 at 10:02:27 AM UTC-5, Bryan Bishop wrote:
On Thu, Feb 26, 2015 at 2:32 PM, Peter Shankles <pshan...@gmail.com> wrote:
  How much would you be willing to pay for this functionality (software will be open source, but there is hardware as well)?

So the hardware would include a spin coater? You haven't given me much detail to work from, here.

- Bryan
http://heybryan.org/
1 512 203 0507

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/8176eeb5-f336-492f-bccb-5c774da53bea%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

On 02/27/2015 05:33 AM, Cathal Garvey wrote:
> h, nice idea! I wonder if even plastic capillaries at that scale are conductive enough to work, I could see it being possible to
> make "pinch-off" capillaries that you fill (by capillary action? :)) and pinch, then lay on your micro-cycler
+1

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F0A396.8060401%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

On 02/27/2015 02:35 AM, Mac Cowell wrote:
> But the thermocycler is so simple in this case. Peltier, sawtooth heat sink with 5-10 ridges, mosfet for switching power, embedded
> thermocouple, microcontroller, and 5-10 glass capillaries, one per sample

Would work fine with forced air heat and cool also. What is a good way to seal ends of capillaries so
they stay pure, yet are easy to unload? Maybe some high melting point wax, (above PCR temps)? Hot glue plastic?

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F0A35F.4030802%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

RE: [DIYbio] At home fabrication of micron scale microfluidics

Would this beat shrinky dink microfluidics? I've managed to make features using shrink sheets printed using a standard toner printer and pdms at around 100-150um and tested with plant protoplasts. With soft lithography, would you use SU-8 or some other material type? How will your software compare to other free CAD programs like draftsight? Will it be photolithography for the master mold production?

Price I would personally pay depends on functionality vs cost. If you can really deliver a simple system (or any system) for production that isn't as finicky as shrinkydinks I'd pay decently for it. It would dave so much time and wasted effort. So much time spent watching templates warp in the toaster oven and whatnot. Also, how will you overcome the hydrophobicity of pdms? I use a corona arch wand but that's not cheap and the microwave method needs a good two stage vacuum pump (also not cheap) so I'm super interested in alternatives.

If the end material is glass or pmma (acrylic) that would be great too. Any thoughts on chip connection and reusability?

Sebastian S. Cocioba
CEO & Founder
New York Botanics, LLC
Plant Biotech R&D

From: Peter Shankles
Sent: ‎2/‎27/‎2015 8:42 AM
To: diybio@googlegroups.com
Subject: [DIYbio] At home fabrication of micron scale microfluidics

Hello all,

I'm new to the DIYbio community and need your perspective on something. 

I'm working on a project that would make microfluidics available to use at home. Because I'm working on this at a national lab, I can't give too many specifics at this time. With that being said our setup would include software for designing devices and creating a master mold for soft lithography. The resolution would be on the order of 100 um, and the fabrication time would be a couple of hours. 

What I want to know is:
  What types of features and designs would be most important to include?
  How much would you be willing to pay for this functionality (software will be open source, but there is hardware as well)?
  What would you be most interested in using microfluidics for?
  Anything else you can think of. I would appreciate any input you have.

Thanks for your time,
Peter

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/edcfcfd1-a71b-4a33-8d2c-f512d7010557%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS

Re: [DIYbio] Electronic requirements for redesign of Arduino PCR thermal cycler

On 02/27/2015 02:29 AM, Mac Cowell wrote:
> It would be interesting to explore a hybrid design combining dynamic conductive heating in the tube block with constant radiative
> heating from a lamp or hot air flow positioned at just the right distance, instead of a heated lid in constant contact with the
> cap. Can the radiative heat source be set up to always add +20C to the exposed cap and 5-10 C to the reaction mixture?


Sure, and with a little fan to help cool. It will be tough to make them always add +20C passively, but it is
easy to use the micro and feedback loop to control it actively.

--
-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
---
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at http://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/54F0A26B.4070903%40industromatic.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS