ThinCert (Ø 24 mm) Membrane Cutter

This is possibly the silliest idea I have ever had for 3D printing a tool, but it is also the one that will probably save me the most time and frustration!

Our laboratory uses Greiner ThinCert inserts [6-well, Ø 24 mm, cat # 657638 (1)] as build surfaces for 3D bioprinted tissues created with our Aspect Biosystems RX-1 Bioprinter (2). We often want to be able to drop the membrane and tissue out the bottom of the holder, which is very difficult if the membrane is completely intact, we need to keep things sterile, and if the tissue is fragile. After trying various methods, the easiest way seems to be to pre-perforate the membrane by 'tapping' with the pointed tip of a scalpel blade. But this is time consuming and subject to a lot of variation - sometimes you cut too much that the membrane fails, sometimes you cut too little that it is still difficult to remove.

This tool is designed to pre-cut the membrane quickly, reliably, and consistently. Four # 11 scalpel blades (3) are glued into the holder at 90° increments, and there are three sets of channels for the tabs on the ThinCert at 30° increments. Together, pushing the ThinCert into the holder 3 times gives 12 cuts.

The images above show you how to get it all done. Briefly, to glue the scalpel blades in place, slide them into the channels a little past where they need to be (something under the tool to raise the top seems to help), place a drop of cyanoacrylate glue behind the blade, then push the blade backwards into position (watch your fingers!). Wait for this to cure, and add a bit more glue to the front/top of the blade. Repeat for the remaining 3 blades. Sterilise the whole unit by soaking in EtOH, and you are good to go! The cutting happens by just dropping the membrane into the holder three times, once into each set of channels - but do note that the ThinCert has one thick and two thin tabs, so make sure you insert it the right way!

1. Greiner Thincert Inserts, 657638
2. Aspect Biosystems RX-1 Bioprinter
3. Scalpel Blades - #11

If you use this design in a scientific manuscript, I only ask that you please state the design was received from Dr. Adrian West, cite this webpage, and send me a link to your published paper!

Print Settings

Printer: Ultimaker S3

Rafts: No

Supports: No

Resolution: 0.1 mm

Infill: 30% cubic

Filament: BASF Ultrafuse PET Black

This is a very easy print, but tolerances are critical for the blade channels and the channels that guide the ThinCert membrane. I suggest using horizontal expansion in increments of ±0.1 mm to get things exactly right. Material is not important, but it needs to adhere well with cyanoacrylate or similar glue. I like PET(x) for superior chemical resistance.