We chose to reproduce the human brain using 3D printers. We found a brain model on Thingiverse to use for the project. The two iterations of the prints were completed using a Stereolithography (SLA) printer and a Fused Deposition Modeling (FDM) printer.

Our first print utilized the Formlabs Form 4 printer, which prints the models with resin. The initial step involved uploading the left half of the brain into the PreForm slicer to properly scale, orient, and add supports for the print. We used the auto-scale and auto-orient functions to ensure the brain size would fit the platform and produce a quality print. Tree supports were added at the base of the left brain and in some crevices due to the blood vessel structures. After proper arrangement, we calculated the brain would require about 580mL of resin. With the assistance of a lab assistant, we installed the clear resin (Clear V4) into the printer, sliced the left brain in the software, and sent the file to the selected printer. The preparation time took about 30 minutes.

The left brain printed in 22 hours. Next, we carefully removed the model from the silver tray and placed it in the IPA Formlabs washer for 20 minutes. We cleaned the silver and black tray used for the initial print with IPA to break down and remove any remaining resin. Afterward, we cured the left brain print for 2 hours at 60° C until the resin model had no sticky regions. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Next, we printed the right side of the brain using the same Formlabs Form 4 printer and clear resin, following all the same steps as for the left side.

This required using the Bambu Studio slicer for sizing, adding supports, and generating estimated print times, similar to the PreForm slicer for the resin printer. The FDM print had a 15% infill with a grid pattern, tree supports, and a layer height of 0.12 mm. We used ruler and caliper measurements from the resin prints to properly scale the FDM models. Next, we prepped the platform with glue to ensure the filament sticks. After preparing everything, we sent the prints to the Bambu printer, which took just under ten hours for each of the two halves (left and right). We used PLA filament for this print, and preparation took about 15 minutes.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Both the resin and PLA prints required sanding. The tools used to sand include sandpaper (torn off), hand sandpaper, and a Dremel. The resin model required the most time for sanding to remove tree supports between the blood vessel details and to ensure the two brain parts would sit flush together. Post-processing the prints with sanding took about 35 minutes in total.

Due to the size of the brain, the right and left brains were printed separately and glued together using super glue. This part took about 30 seconds for each model to stick together.

The next step in post-processing was painting. Both prints were spray painted with primer, followed by 2 coats of candy pink after the necessary dry times. After allowing the brain models to dry, we painted the blood vessels red. The last step was to lightly spray-paint the brain models in the same pink to give a more realistic look to the pinkish-gray look of brains and the multiple blood vessels. 

 

Cost analysis of 3D-printed brain models

Below is a photo attached of our clean workspace after we cleaned up.