3D Printing a Brain

This was a fun project. It's also funny to me that the first artificial brain I made was 3D printed rather than anything to do with my PhD.

A friend was finishing their PhD in neuroscience and their partner to commemorate their achievements. Doing a neuroscience PhD, my friend had MRI scanned a lot of brains (as you do), including their own.

We got a hold of that scan, and decided to make a little trophy.

The process was this:

1. Convert the DICOM file to a mesh.
2. Clean the mesh manually in Blender to make it watertight and printable in two halves. Handily, brains come ready split into two hemispheres with a flat-ish plane dividing them.
3. Print the halves on a SLA printer. SLA was a good choice as it gives a nice smooth finish. No layer lines. No loosing the will to live sanding a surface covered in folds.
4. Create a negative mold for each half by casting around it with high-temperature silicone (Smooth-On)
5. Melt some pewter, pour it into the silicone molds, leave to cool.
6. Extract the halves, the silicone is flexible enough to allow this even though the brains folds locked into it.
7. Glue the halves together with epoxy.

For the base I started with a piece of stock about the right size and used a profiled router bit on the sides and back edge. I swapped to chamfer bit to do the front. The brain rests on a little 3D printed I just plaque online.

All in all I learned about medical file types, tried several new manufacturing processes, and was pleasantly surprised how polished I got the final result.