Neuralink builds patient-specific brain implants in two steps: machining a custom skull cap from plastic, then casting a hydroshell component from a mold made from the patient's MRI data the night before.
Step 2 would be the skull cap. We actually machine skulls out of a block of plastic. You'll see the machinist go in and an anatomically accurate skull come out of a chunk of plastic. Third step will be assembling the brain. That starts actually the night before, where we will pour a custom hydroshell into a proxy mold, and the mold is built from the MRI of the patient that we're building the brain from.
