Those are some significant issues. If I’m getting this all right, the implants can grow out if the skin isn’t sealed around the object or it being solidly anchored in some way. Infection happens by ‘stuff’ building up and not being able to be washed away from an opening in the skin (ie not completely sealed). And transdermals/microdermals can be painful/ripped out by catching on stuff.
I’m probably way off base, but off the top of my head something like graphene could theoretically be integrated by the body and treated like natural tissue. This could solve the issues at the cellular level of creating a theoretical ‘perfect seal’ around the implant. If there’s a perfect seal then gunk and cells can’t build up - they could be washed away in the shower. This would be easier if the surface of the implant was smooth or typically had some sort of cover to prevent ingress into a socket (magnetic coupling ala Volta cables.
The implants could be anchored either to internal structures like bone or cartilage, or perhaps have a design similar to drywall anchors to prevent growing out. I don’t know if this would work or not, but I’m just spitballing.
And with regards to bumping on things and it being painful - to a certain extent that’s life. I’m sure we’ve all stubbed our toes or jammed our fingers in doors or drawers. It’s painful and we learn to be more careful and have better self-awareness. This could be theoretically improved by having some level of sensation on the implant (especially if it’s extruding from the body a lot), or if the implant is effectively flush with the skin (like in the Cyberpunk screenshot I shared) then the chances of bumping against anything is relatively minimal. Yes, something like the iron mohawk would be a problem, but I’m thinking of more functional than aesthetic implants here.
So in summation we need some anchoring structure like osseointegration, a chemical structure that the body tries to integrate such as graphene, and a functional design that is as close to flush with the skin as possible to minimise accidental bumps and knocks. This is all theoretical of course, but it’s fun to think about and imagine.
~ Jamie