Hey everyone. I saw a prior thread discussing a 3D printed ETC chamber and would like to jump in with my own contribution. I've also been working on a 3D printed design for a couple of months and it is finally at the point where I'm comfortable offering it for others to use. The key difference between this chamber and other 3D printed chambers is that it's made from glazed ceramic. I decided to go with this print material instead of extruded thermoplastic for a number of reasons:
1) heat tolerant;
2) chemically resistant;
3) mechanically stronger (no warping under pressure);
4) 100% water proof;
5) 100% light proof to protect photosensitive samples;
6) much better resolution and tolerances (negligible variability between prints)
I've printed and mechanically tested various prototypes (lab is setting up to run the full CLARITY protocol but not quite ready yet) and can say that it is water tight under typical ETC pressures. I'd love for someone who is already up and running with the CLARITY protocol to try clearing a brain in it!
The current design has some nice features and optimizations (see photos on Flickr at
http://flic.kr/s/aHsjH3Q3MC):
1) chamfered internal edges to minimize trapped bubbles;
2) use of a flat rubber gasket instead of an o-ring to provide a reliable water tight lid seal;
3) parallel electrode ports to make electrode insertion easier;
4) adjustable/replaceable electrodes w/ custom gaskets to prevent leaking;
5) simple and foolproof lid securing system using two rubber bands
The chamber is available on Shapeways (
http://tinyurl.com/m2qjana) in multiple colors. In the spirit of open hardware you can freely download the .stl file from that site as well if you want to try printing it on your own. I can't host the original design files on Shapeways, but if you'd like access to those just shoot me a message.
Full disclosure: you'd save about $7 by printing it yourself from the .stl file, but that little extra helps me design and pay for prototypes to improve this design and develop other awesome open science projects.
Hope you guys like it!
Comments
After testing various systems, the best performance was achieved using nested silastic tubing and a PVC wire cap.
The 0.5 mm platinum wire is initially inserted into a silastic tube (0.6 mm i.d. x 1.0 mm o.d.).
This is then inserted into a larger silastic tube (1.0 mm i.d. x 2.0 mm o.d.).
This is then inserted into a PVC cap that serves two functions: 1) maintain electrode alignment; 2) provide a convenient point for handling the electrode assembly.
The electrode insertion points in the 3D printed ceramic ETC chamber are sized to give a water-tight fit when the electrode assembly is firmly in place. To remove the electrodes just pull on the PVC cap and the entire assembly will come out replacement / readjustment.
The silastic tubing should be pretty easy to acquire, but the PVC caps might be more elusive.