I'm also concerned about how such devices will affect and be affected by cavitation. Cavitation inside the skull has been found to happen in concussion injuries in explosions. It's also thought that it can happen with the smaller impulses coming from punches and everyday impacts. Are the devices subject to cavitation, particularly the long, thin parts, and what happens to those long thin parts inside the brain when they are subjected to cavitation?
EDIT: This device is only penetrating the scalp, but other devices like Neuralink penetrate into the brain.
This particular device doesn’t even penetrate al the way through the scalp, so the skull would likely obliterate these long before they reach the brain.
Motion is a problem for things that are inserted into the brain, but people have been getting DBS and sEEG implants for 30 years, and it’s manageable, though not totally solved.
It's barely even penetrating the scalp. The needles (really better described as spikes, they have a fair amount of draft, about 20°) only puncture the strateum corneum - outer layer of dead skin cells and lipids.
EDIT: This device is only penetrating the scalp, but other devices like Neuralink penetrate into the brain.