How to make Teflon Spacers for your PCBIMS

Our most recent PCBIMS designs utilize Teflon spacers between each electrode and PCBIMS spacer. Once compressed, these Teflon spacers ensure the IMS is gas-tight. We use a Cricut Explore Air 2 to create our Teflon (or Kapton) spacers. Additionally, the Cricut can be used to ensure the fit of the holes for electrodes top board for new electrode/spacer designs by creating a top board from paper before ordering a PCB variant. Below is a tutorial on how to convert PCB designs to cut with a Cricut:

Materials List:

  • Cricut machine/account
  • PCB editing software that supports .brd and .dxf files (we use Eagle autodesk)
  • Roll of Teflon the size of your cricut mats

Teflon:

We typically use a thickness of 0.1 inch ordered from McMaster-Carr:

https://www.mcmaster.com/8569K41

a 12 inch by 12 inch sheet (1 cricut mat) will give 49 spacers. For 1 IMS with a 29 electrode desolvation region and drift region (~10.2cm long for each) approximately 116 Teflon spacers are required plus some tabbed Teflon spacers for the tri-grid gates (3 per gate attached to a pulser, one for a Faraday plate). Thus roughly 3 ft x 1ft are required minimum per IMS.

From the Open Source PCBIMS Link on the Github account, download the respository if you haven’t already
Open the Spacers .brd file and delete spacers (on the top level under lines and holes) so that a 7×7 grid of spacers is present. This will fit onto a 12″ by 12″ Cricut mat. Choose the option to export as a DXF file
Delete the option to fill the areas when saving and make sure the export unit is in inches to match the units for the Cricut software. Choose the file name you want and where to save it.
Load the Cricut design software. Make sure your machine is specified and click on new project
Click upload image and navigate to where you saved your DXF file
Once it is uploaded hit save
Insert the spacers into your new project
Adjust the spacers so that they fit within the 12″ by 12″ square of your mat. Make sure you attach the images in the bottom right corner. Otherwise the shape of the spacers will not be preserved and will be divided into a series of random circles and lines. It will take forever to load and attach the images since it is a large file.

Depending on the type of material and thickness used, you will need to adjust settings on your cricut mat accordingly. We found the green (medium stickiness) works well for 0.05″ or 0.1″ Teflon and the blue (light stickiness) works well for Kapton. We use the cardstock setting on the Cricut air for both materials.