RE: Microfluidics Chat Thread WAS: [DIYbio] Paper request

See attached photo for an example of my crappy attempt at making pdms more hydrophilic using a UV sterilizer (the breadbox type). 30 minute exposure on both a piranha-treated microscope slide (15min in a solution of 3:1 h2so4:h2o2 *dangerous, corrosive, always use appropriate PPE*) and a freshly minted pdms chip. I dried the slide with a kimwipe and used scotch tape to remove residual dust from the feature side of the pdms chip. Then I just laid the slide and pdms chip (feature side up) into the chamber and set a timer for 30 minutes. Then quickly place the pdms chip feature side down onto the slide and apply gentle pressure around the features. Be sure to not squash the channels.

PDMS was the knock-off ML Solar brand from eBay. 10:1 mix by weight. Degassed in a desiccation chamber to 25+inHg twice and incubated at 60c for 1hr.

Pdms chip was casted in a plastic Petri dish on a shrunk shrinky dink printed using graffix brand shrinkable sheet (white not clear!). Something funky about the clear version. Sticks to everything when in the oven, got better results with white sheets. Printed with a standard brother monochrome laser printer (toner). Chip design taken from template PowerPoint slide from this site:

http://chemistry.beloit.edu/Edetc/nanolab/shrink/index.html

Its a simple gradient generator. Still not as fluid and wettable as I'd like it to be. I used a straw to mouth-vacuum from the outlet port. Aside from some funky phenomena on the rightmost channel, it did seem to separate decently. I used food coloring as the indicator.

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

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From: Nathan McCorkle
Sent: ‎12/‎29/‎2014 3:21 AM
To: diybio
Subject: Re: Microfluidics Chat Thread WAS: [DIYbio] Paper request

On Sun, Dec 28, 2014 at 8:47 PM, Nathan McCorkle <nmz787@gmail.com> wrote:
> On Sun, Dec 28, 2014 at 8:45 PM, Nathan McCorkle <nmz787@gmail.com> wrote:
>> https://raw.githubusercontent.com/nmz787/microfluidic-cad/master/implicitCAD/output/tobacco_mesophyll_protoplast_fusion_device.jpg
>
> and yeah I know I need to improve the funnel-of-posts angle so the
> edges follow the pitch of the posts, so i.e. cells don't get stuck.

Which is demonstrated on the macroscale with marbles:
https://www.youtube.com/watch?v=03tx4v0i7MA