novelchip

I'm glad to see that also you got nice results with this simple trick. by the way as i understand French I read your results description on your blog. If you try with a needle smaller than 0.6mm you should be also able to get laser-sharp cutting of rubber.

Wow ! Great work!

Gigantic!

well done !

great finish ! Nice work.

you are perfectly right.

Thanks !

There is actually no need to hold it down strongly when using a needle. I simply layed them down on my work surface on which I strap some double side adhesive tape. Another even simpler possibility is to lay the sheet on a another sacrificial rubber sheet. Since the needle cuts really well and I cut down in the material by repeated small steps of 0.1 or 0.2 mm this is sufficient. The forces are so low that allmost no fixing is required.

Thanks a lot for your insightful appreciation ! Yes, PVC rubber cuts quite well also and indeed I am planing to use precisely PVC rubber sheets + commercial precast silicone rubber sheets to make microfluidic devices. This simple trick indeed allows such easy and really ultrarapid complete prototyping of silicone microfluidic circuits that I still can't believe it allmost.

Its ordinary milling work..the needle spins (e.g 16000 rpm) and advances along the toolpath at some 100-200 mm/min. The material is engraved one by engraving deeper and deeper in each pass. I usually set the depth increase between passes around 0.1 to 0.2 mm or in some cases 0.05 mm even though it slows down the work process. Admittedly it is not as fast as cutting with a knife but compared to mold preparation and casting it is hundred of times faster

Thanks ! I had not used any zero helix nor negative heliz tool before. I had used sharp tip single flute PCB V scoring tools before. As the tip is at the center of the tool in this case I also got kind of cutting action rather than milling and of course sidewalls of milled grooves are angled. With the needle as you say I have kind a single flute zero helix angle tool even though a very sharp tipped one with the tip rotating around a circle. Roughness of milled sidewalls is not so exceptional and improving it would not be bad. So I might try also zero and negative angled endmills. Thanks for the suggestion. I have never used dry ice since I don't know where to get it easily from (and possibly at low cost). At the moment I am happy with the result and happy to avoid such complications bu...

Thanks ! I had not used any zero helix nor negative heliz tool before. I had used sharp tip single flute PCB V scoring tools before. As the tip is at the center of the tool in this case I also got kind of cutting action rather than milling and of course sidewalls of milled grooves are angled. With the needle as you say I have kind a single flute zero helix angle tool even though a very sharp tipped one with the tip rotating around a circle. Roughness of milled sidewalls is not so exceptional and improving it would not be bad. So I might try also zero and negative angled endmills. Thanks for the suggestion. I have never used dry ice since I don't know where to get it easily from (and possibly at low cost). At the moment I am happy with the result and happy to avoid such complications but having smoother surfaces of course would be nice. So eventually I'll give it a try.

I'm glad I have suggested you an idea. Good luck !

Fascinating proposal ! Indeed I found that what you are talking about exists as Stirling engine

you can buy them also on e-bay or amazon

Thanks ! Interesting idea.

excellent idea ! yes !

Here is a video of my 4 bit binary fluidic counter made by mixing CPL fluidic logic and resistor transistor fluidic logic. Works like a charm ! https://vimeo.com/231916371

In my opinion it would be even more interesting to try to operate these circuits with pressure instead of vacuum although achieving good sealing will be more difficult.

Finally also my miniatured version (universal gate chip size 8*8mm^2) works as it should using one chip as MUX and the other as buffer. With the circuit connected as shown in the photo and using a syringe as vacuum supply i determined that the circuit consumes 0.3cm^3 per switching operation and i could perform 100 times switching with just 30cm^3 of air!

About the latch circuit besides possible leaks you might consider to insert more resistive feedback channels in the loop since i also could not get it to work unless the feedback loop introduces a sufficient delay as i mentioned previosly. Adding resistance or capacitance in the feedback loop made it work for me and i could cascade several cpl latch curcuits.

Wow! Well done! I like in particular your way to cast the silicone microfluidic layer and will certainly try to replicate the idea using my cnc mill to make such a mold. One question: how well does the glue stick to the silicone. I thought it us hard to glue silicone to a surface.

To help develop microfluidics you may consider to "publish" your chip also on the new "Metafluidics" repository ! https://metafluidics.org/

To help develop microfluidics you may consider to "publish" your chip also on the new "Metafluidics" repository ! https://metafluidics.org/

o help develop microfluidics you may consider to "publish" your chip also on the new "Metafluidics" repository ! https://metafluidics.org/

thanks