Has anybody attempted to print microfluidic systems (tiny channels within an object) using FDM machines ?
Was thinking about the possibilities of doing diy printheads for liquid polymer type systems (uv curing for example) that would allow multiple materials/ parallelized printing .
Found a related good read:
and for some informative (and fun !) look into microfluidics:
http://groups.csail.mit.edu/cag/biostream/
If no one has experimented with it, as soon as my Ultimaker is working again I intend to do some tests to see how fine we can go, and IF it would be even possible as an open source/diy alternative to liquid based printing (2d & 3d).
Lots of possibilities !
Yep it’s been done and is being done here too mate : http://www.chem.gla.ac.uk/cronin/
I’ve also seen someone else looking into this on instructables. I’m doing to same but not with FDM as it’s a bit limited, and a bit big.
@nathan_burley thanks for that ! will take a look ! 
When you say “FDM is a bit big” : do you mean the minimal feature size of FDM printers is too big to create channels for microfluidics?
Yeh, that’s what I’m thinking. The guys in Glasgow are using 1.5 mm channels …which are massive relatively speaking.
I’ve managed to get down to 0.3 mm channels but that’s it and this isn’t using FDM either. Have you thought about removing supports etc - FDM’s may have soluble supports in some cases but how do you clear a channel of solid plastic?
ouch , yeah 1.5 mm seems way beyond the recommended sizes for microfluidics!
0.3 mm seems better : what tech did you use for those ?
Not sure supports/soluble supports would help, with fdm it has more to do with “repeatable resolution” and nozzle size. I really need to get my printer running again to test this. (the smallest features I remember doing were around 0.5mm on a huxley, on the x/y axis ).
Changing print orientation might help for FDM though, as the vertical resolution can get way lower than what the x/y axis can do …
well, I look at it like this: it’s above micro fluidics because the strength of microfluidics is that physics acts in odd ways when volumes are so small. What you could look at, what I’m also looking at, is ‘can 3D printing make possible with fluid handling what is not possible with other manufacturing techniques?’.
I think 3D printing has the capability of producing some really novel processes for making fluid handling devices which would be impossible to make in any other way: http://www.youtube.com/watch?v=25ElCGkQLTU like this scaled down?
@nathan_burley totally agreed!
I am still of the mind that 3d printing’s strenght are under-utilized, and the example you mention is one of those things
To be honest I was looking into microfluidics and “fluid” handling devices as call them not necessarily for the very special properties of microfluidics themselves but for two main objectives:
- possibility of bootstrapping alternate methods of 3d printing with greater level of control (material mixing, transparent materials with less issues with crystallization than fdm for optics etc)
- targeted irrigation systems (lab use )/ liquid “control” systems (medical pumps, spray nozzles for moisterization etc)
Also thanks for the link , very nice device, will give it a print!
I totally agree - most of the real advantages of 3D printing are being lost in the message. We’re just scratching the surface of what’s possible even as a general manufacturing technique without bio-printing and the like.
I’m interested in what you come up with to be honest. I don’t want to say too much about what I’ve done already because I don’t want to colour what you’re going to do - you obviously have your own ideas and I’m pretty interested to see what you make.
Optics-wise iMaterialise have a material which is very clear (at least to the naked eye). I tried to print channels in it but a) it’s very expensive and b) I had no luck with printing complex channels it in. It work for more simplistic geometry though, who knows. May be worth a look for optics.
What do you mean by targeted irrigation systems?
Medical pumps might be an issue due to the low pressure 3D printed parts can handle - though I’ve actually not tested the pressure tolerance of my parts yet… might have to get on that.
I think that for fluid control there’s a lot that can be done since the cost of the parts is actually pretty low. If you could replace a lot of different parts using a couple of 3D printed devices then you could make them simpler, smaller, more efficient and possibly cheaper too. Making components for larger pieces of kit also means the number of parts required per year often drops to less than 1000 - perfect for 3D printing!
However, when you get down into the consumer devices (point of care testing kits and consumables like moisturisers) parts need to super cheap and mass produced - 3D printing isn’t great for that (at least not yet).
heh! I wondered how long it would be til you found that photo. That was a while back. I’ve been push to create something really different since then and I’m now at a stage where I have something which could not be produced using any subtractive manufacturing method.
But I haven’t FDM at all yet…!
@Mark_Moissette_ckaos @nathan_burley please post your findings, I’m really interested in it. Maybe we can find some synergies. Want to start with my master thesis in November looking into fluid and viscous stuff.
@nathan_burley sorry about the late reply, had a very busy week.
Glad we agree:)
Sadly , don’t hold you breath for what I may come up with, I have very little time to move this project forward as much as I would want.
But the initial experiments I started / wanted to explore more was along the lines of 3D printed peristaltic pumps + valve systems with a “plugable” system of channels .
I also looked a bit into what easilly available 3d printed materials are chemically neutral : there was an article a while back about a lab trying out 3D printed tools as reactors (in the bio lab sense). I’ll try to find it again.
targeted irrigation system : close to the roots delivery of nutrients for hydro/aeroponics systems (for the later, a replacement for the piezo nozzles would be a neat thing).
I also wanted to experiment with a way to add “open” channels on the surface of “template” 3d printed objects to allow for growth of mycelium as a way to produce “organicly grown” parts. (mycelium has a lot of very interesting mechanical /thermal etc properties)…
Thanks for the info about the i materialise material !
What kind of 3D printer are you using (judging from the picture in question, resin/uv curing / dlp)
For optics, I still am unsure of how things would work given the “layers” generated by 3d printers.
Are you sure about the issues with pressure in 3D printed parts ? What little I did experiment with (pumps), I found parts very sturdy.
The thing is, if you combine the flexibility given by 3d printing and things such as parametric modelling etc, you could really work around the higher “price per unit” (or something like that).
What were those 3d printed “hydraulic” parts for ? (if you don’t mind sharing ?)
@Henrik_Peiss will gladly share whatever I can
And would love to spend more time and “find synergies” (as you say on this !
Have you decided if you are going with “bio” production of plastics etc that we discussed or something else ?
@Mark_Moissette_ckaos hoped to see you on the +OS3DPC in FFM for discussing more about our ideas and find maybe synergies.
Just sketching out different routes and the needed equipment for realisation, decision within the next weeks
Hi guys, sorry I’ve been out for a while (busy week for me too!).
+Mark Moissette I have seen 3D printed DC motor driven pumps which could easily be incorporated into fluidic devices when scaled down: http://blog.ponoko.com/2010/11/23/3d-printed-water-pump/
I’ve also seen a 3D printed stepper motor too which might be incorporated into something like this…it’s a bit big at present though 
: http://www.youtube.com/watch?v=paT63-8DLbs
I love the mycellium idea - that’s pretty sweet. So would you be looking to create some sort of 3D printed ‘jig’ which you could grow a mycellium superstructure around? If so, are you thinking of something like the dual material FDM printers where you could print the ‘jig’ in PVA, grow the mycellium part and then dissolve the jig afterwards? Have you considered growing polymers…?!
RE: pressure: Well I currently work with HPLC systems and they run into the 1000’s of psi!! I’m doubtful the 3D printed parts are capable of that but then, for the most part the systems I’m thinking of would operate at or around atmospheric pressure, so that’s not an issue really.
I’ll be honest and say that I’m massively conflicted about talking about what I’ve been doing and working on for the past few months; On the one hand, I LOVE Open Source and I recognize it’s enormous value. I also recognize that money can still be made when working with open source tech. On the other hand, a lot of the principles I’ve been working deliberately rely on resources so freely available that literally anyone could use them to replicate my work… in very little time. I’ve spent a good 6 months dreaming about doing this and the last 3 months actually working on it - despite it being such an arcane and obscure niche that most of the people I talk to about it say they have no idea what it might be useful for… there are days even I wonder whether it will be useful.
However, I’ve been told by a uni professor that I should do an MSc by research as I’m basically doing it in my own time anyway. As a result, I’m not sure I want to just give away all my work and let someone else write it up first (certainly no offence intended @Henrik_Peiss but I’m sure you see where I’m coming from). What I do want is cooperation though, and I’m keen to offer help and lots of ideas where I can. I am keen to explore how we might be able to all work together though so I’m more than happy to talk it through.
I will say that the parts I pictured are printed via an SLA type method and they contain channels as small as 0.3 mm in diameter. Having no practical way of testing such small volumes at home I’m not sure of the accuracy of those channel sizes but I can say for sure that the smaller I design them, the smaller they come out: 0.2 mm channels are not full proof. Also, I’ll say that that photo was taken a long time ago and I’ve definitely taken some big steps since then…!
@nathan_burley - got your point relating information sharing. Will answer more detailed on the weekend.
For measuring your channels sizes: maybe use a Object-Micrometer / stage micrometer 1 and a hacked webcam microscope 2 . Didn’t check the spects in detail, but should work.
@Henrik_Peiss yeah , really too bad we won’t meet live to discuss these things (and more !) 
Not enough time & money sadly.
perhaps we could do a hangout to discuss things a bit ?
@nathan_burley
those have been on my “to print” list for a while now They are damn cool!
The “scaling” down is a bit problematic though, from experience : I had some issues with printed “tubing connectors” that were just meant to plug in to standard size aquarium vinyl tubing, but that was way back (I did buy a few tiny motors to test things out further).
mycellium: multiple ways to go about this: either print a structure in a material that can be completely absorbed (used as nutrient etc) by the mycellium , or , exactly as you said, a 3d printed jig .
There are some interesting properties of mycelium when grown into silica rich materials (temperature resistance / fire proofing etc). (see here for example : http://www.ecovativedesign.com/)
Growing polymers would be fantastic ! (don’t even get me started on interfacing electronics with a “grown” upper layer for sensing…
sadly I don’t have access to lab equipment to really do some interesting stuff.
Pressure: wow , ok , 1000’s of psi is way beyond the range I was thinking of so yeah in that case, “basic” printed parts won’t work indeed!
I can understand your inner conflict, it is not always easy to choose going fully open source but frankly, I have been there, and now I regret not open sourcing things straight away, as it would have helped some of my projects from dying of when hitting a roadblock , or a period of “doubt” as you put it. But no need to force yourself into releasing something if you don’t feel ready for it (I HATE releasing stuff I feel is not ready for external consumption).
So collaboration , discussion at your own pace is fine by me: I am already juggling full time job/family life/ too many projects, so I am not exactly in a hurry to add more, however interesting haha
pics/parts : @Henrik_Peiss is spot on I think , and perhaps 3d scanning could help as well ?
Have you perhaps got more recent pictures if things are much improved? (if you don’t want to share publicly , I’ll drop you a mail)
Offline email between the three of us sounds good - for no other reason than this post is getting long and this skinny tab isn’t great to type into!
@Henrik_Peiss good call on the home brew microscope stage! I was wondering whether the one below might be enough …that sure won’t take an MSc in engineering to build lol!: http://www.youtube.com/watch?v=fHieORuEsnQ
Was thinking that I could use the lens from the DVD drive I ripped to bits the other week - I was looking to use the stepper motor and stage as a means of driving pistons into these types of devices but the stepper just doesn’t have the torque to work even pumping at atmospheric pressure.
The parts are getting pretty thick in places too so I’ll need some good back lighting. Though I try and keep the main layer at 3 mm, I’ve got plenty of surface features working like Luer Locks, push-fit barbs and piston housings working now, those’ll get in the way a bit.
I was thinking originally about volume measurements rather than doing things this way but even with access to low volume positive displacement pipettes I can’t measure them easily; Since a PD pipette will only dispense the volume you set it to, and since if you dispense the calculated volume of the pipette (say 10 ul) and you overfill the channel, you still don’t know how much you’re over shooting by…
@Mark_Moissette_ckaos I’m away with work this week but I will have plenty of pictures next week once I’m home again. I’m currently working on Arduino control for a mini dilutor / mixer / incubator device just as a proof of concept really.
I’ve been looking at making devices in ways which don’t require a lab or any kind of high tech equipment at all. Microfluidics is an AMAZING suite of technologies but for most people (me included) it’s out of reach due to the chemicals and equipment requirements. My current method requires none of the above… although I am playing around with something a bit nasty at present, I’d like to replace that with something more freely available!
The Open Source thing is really about credit if I’m honest. It sounds ridiculous, and incredibly vain but I cant deny it. You two guys among the VERY few people actually looking at this and thinking…‘why has no one else figured this out yet?’ For a long while I thought I was missing something obvious, but the more I thought about it the more I was convinced it was possible. I put up some of my own cash up and tested out some ideas. My fist experiment in SLS was an out and out flop but the photo of the channel matrix was my third ever printed part. There have been plenty of low moments working through the various issues though which, let’s face it just comes with the turf. I really want people to bash ideas around with; I’m an ideas guy - never happier than when I’m problem solving - but, I also really want the recognition for being in early (“vanity, definitely my favorite sin”) even if it is just a journal article lol!
oh btw if you haven’t checked out this link on my page, it’s pretty cool! He’s still using some hard to get stuff though and the process takes a long time but you can’t deny the results are impressive!
http://www.instructables.com/id/FluidBricks/