Microfluidics for Biohacking Hack Chat

Krishna Sanka will host the Hack Chat on Wednesday, July 7 at noon Pacific.

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"Microfluidics" sounds like a weird and wonderful field, but one that doesn't touch regular life too much. But consider that each time you fire up an ink-jet printer, you're putting microfluidics to work, as nanoliter-sized droplets of ink are spewed across space to impact your paper at exactly the right spot.

Ink-jets may be mundane, but the principles behind them are anything but. Microfluidic mechanisms have found their way into all sorts of products and processes, with perhaps the most interesting uses being leveraged to explore and exploit the microscopic realms of life. Microfluidics can be used to recreate some of the nanoscale biochemical reactions that go on in cells, and offer not only new ways to observe the biological world, but often to manipulate it. Microfluidics devices range from "DNA chips" that can rapidly screen drug candidates against thousands of targets, to devices that can rapidly screen clinical samples for exposure to toxins or pathogens.

There are a host of applications of microfluidics in biohacking, and Krishna Sanka is actively working to integrate the two fields. As an engineering graduate student, his focus is open-source, DIY microfluidics that can help biohackers up their game, and he'll stop by the Hack Chat to run us through the basics. Come with your questions about how -- and why -- to build your own microfluidics devices, and find out how modern biohackers are learning to "go with the flow."

[Banner image: Cooksey/NIST]

Event Logs

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Hack Chat Transcript, Part 2
Dan Maloney • 07/07/2021 at 20:09 • 0 comments

John Uskglass12:51 PM
Awesome awesome

Dan Maloney12:52 PM
Yes, a transcript will be posted right after the chat!

isaac12:52 PM
Have you ever tried out methacrylate and a photomask to make molds? It seemed to be in vogue for a while but I found it pretty tough to work with

rkrishnasanka12:53 PM
Lol, I never thought people would come to me for PDMS hookups

isaac12:53 PM
You're our new plug

rkrishnasanka12:53 PM
@isaac no I never heard of methacrylate, but a quick wiki is telling me that it's gonna be a pain

kdharbert joined the room.12:54 PM

kdharbert12:55 PM
Anyone put much effort into frequency tuning a tesla valve?

Les Hall12:57 PM
not here, though this conversation has me all motivated about testing with tesla valves!

kdharbert12:57 PM
I was an hour off on the start time. Bummer. I had some questions regarding surfaces textured with tesla valves.

rkrishnasanka12:57 PM
@kdharbert what do you mean by frequency tuning ?

Inne12:58 PM
I did microfluidics once but it was the other way around (from the IGEM approach ) casting PDMS liquid on a plate with electrospun protrusions to make a cast. Then glue it to a glass plate (with UV epoxy??) and poke holes in the PDMS with tubes, then add tubes for inflow outflow. This was for microscopy. Is this still done or are there easier ways, as the Igem methods, with the same benefits.

kdharbert12:58 PM
According to what I've seen the diodicity increases with higher frequency

Dan Maloney12:58 PM
If you need a reminder email for the Hack CHat, sign up here: http://eepurl.com/cDE5-H

kdharbert12:58 PM
it drops at a low frequency, hence 'slightly leaky'

Dan Maloney12:58 PM
Sends out a reminder 30 minutes before each chat

rkrishnasanka12:59 PM
Also here are my Shameless plugs:

Check out the interactive design tool: https://3duf.org

Stay tuned for a microfluidic hardware description language I'm working on called: LFR (Liquid Flow Relationships) (supported by https://neptune.fluigicad.org)

If you’re doing Academic microfluidics, check out my colleague’s CNC milling paper: https://link.springer.com/article/10.1007/s10404-018-2048-2

Some open source efforts we are putting together for Microfluidics : https://distributeddiagnostics.org/

Chat more about open source microfluidics and join the small community we have on this and look at what we putting together: https://join.slack.com/t/dist-diag/shared_invite/zt-rci22g8h-JnzoZw7liJwFilAFoKu_jg

kdharbert12:59 PM
I suspect they can be shaped to manipulate frequency response.

isaac1:00 PM
What substrate do you use for the channels when milling? Acrylic?

rkrishnasanka1:00 PM
@kdharbert yeah I'm pretty sure they would have a frequency response since most of the cases I considered only continuous flow, so I never thought about that. It should be possible to characterize it though

isaac1:00 PM
If so, any tips on small channels? I've got a 1/100" bit ready to go but I've been to nervous to try it out haha

Dan Maloney1:01 PM
We're at the top of the hour, and while I hate to break off a cool discussion, we have to give Krishna the opportunity to sign off if he needs to. Of course the Hack Chat is always open, so feel free to stay on and keep the conversation going.

I'll just put the official wrap on this chat with a big thanks to Krishna for his time today, and to everyone for a great discussion. Thanks all!

rkrishnasanka1:01 PM
@isaac we have all the settings for Polycarbonate, and all the methodologies, characterization / test files if you want to figure out the feeds and speeds for acrylic or any other material

dominguesallysson joined the room.1:01 PM

kdharbert1:02 PM
@rkrishnasanka Right, once that is dealt with vibration at the right frequency should be able to drive fluid uphill.

rkrishnasanka1:02 PM
@isaac 1/100 is super easy, its what they let me mill with, in the lab :P (I'm not allowed to use the <100um endmills)

rkrishnasanka1:04 PM
I should be online for a little longer if you all have any more questions,...
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Hack Chat Transcript, Part 1
Dan Maloney • 07/07/2021 at 20:08 • 0 comments

Dan Maloney12:00 PM
OK, people are still coming in and I see a LOT of new names, which is great. Let's get started! Welcome to Hack Chat, I'm Dan and I'll be moderating along with Dusan who'll be along a bit later. Today we welcome Krishna Sanka, who's doing some cool work with microfluidics for biohacking.

Hi Krishna! Can you start us off with a little about your background?

makingofamaker joined the room.12:02 PM

empil12:02 PM
there no sound in this chat?

Dan Maloney12:02 PM
No, this is a text chat, like a reddit AMA

empil12:03 PM
thanks

rkrishnasanka12:03 PM
Hi All ! My name is Radhakrishna (aka Krishna). I'm currently a Ph.D. candidate at Boston University working on how we can simplify and automate the design of microfluidic devices for applications in synthetic biology and beyond. What this roughly translates to is that I create a whole bunch of CAD tools and go about telling microfluidics designers that they're going about everything the wrong way :D

Nicolas Tremblay12:04 PM
So you're an engineer

bluevex joined the room.12:04 PM

rkrishnasanka12:04 PM
Before coming into the world of microfluidics I spent some time designing electronics, software and photonics. So I have a bunch of experience on using CAD tools.

bluevex12:04 PM
hello! What kind of devices are you working on now?

rkrishnasanka12:04 PM
@Nicolas Tremblay yes I'm an engineer !

Inne12:06 PM
Microfluidics has appealed to me for quite some time. But I always wondered what I, a hobbist Maker, could apply it to. Since Microluidics is your Hammer do you see a lot of nails. Any unexpected stuff you suddenly realized could be done via it??

Michael joined the room.12:06 PM

dE3OB2 joined the room.12:06 PM

rkrishnasanka12:07 PM
@bluevex my colleagues and collaborators are working :

1) Droplet based devices for yeast and ecoli

2) Droplet based devices for microbiome

3) Single Cell imaging (e.coli)

L29Ah joined the room.12:07 PM

L29Ah12:08 PM
@rkrishnasanka are the CAD tools you develop these days open source?

radiologyrocks joined the room.12:08 PM

rkrishnasanka12:08 PM
Over these projects, we end up fabricating microfluidics via:

1) CNC milling

2) Laser Cutting

3) Photolithography

rkrishnasanka12:08 PM
Yes, they are open source!

Les Hall12:09 PM
not 3d printing?

Dan Maloney12:09 PM
Any "cultural" issues between you as an engineer and the scientists you work with? My background is in biology, so I could see where there might be some friction.

radiologyrocks12:09 PM
You mentioned the CAD tools - which ones do you use? Also, tell us more about the pitfalls of the microfluidics designers you describe above.

John Uskglass12:09 PM
I have been deep diving into consumer/lab microfluidic devices for constant delivery microfluids. (For my purposes I am colouring forsting. ) Have you looked at peizoelectric micro pump delivery systems?

Les Hall12:09 PM
even on formLabs with all their detail?

rkrishnasanka12:10 PM
@Les Hall not yet, we are hoping to have some collabs by the end of the year with 3d printing

worm959 joined the room.12:10 PM

Les Hall12:10 PM
ty

rkrishnasanka12:11 PM
@Dan Maloney yup, we face this a lot. Scientists care about the single killer experiments (in biology) or the n-th unique variation of a microfluidic geometry. They don't care about building working replicable systems.

Inne12:11 PM
Are there any development with metal 3D printers making the molds for the, what do you call those cubes, chips, chambers, channels?? Since metal 3D printing is done via laser sintering

rkrishnasanka12:12 PM
I don't really blame them because you won't get your nature paper with just reliable microfluidics, its not boogie enough for that

rkrishnasanka12:13 PM
@John Uskglass yes the new pumps look really cool. I, unfortunately, haven't had a chance to play with those yet.

rkrishnasanka12:13 PM
I'd love to use them for some of my next hardware projects, right now I'm grinding out software

rkrishnasanka...
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