Something I’ve seen mocked up by AggeIw (https://aggeiw.deviantart.com/art/Give-me-a-Hand-216238791)
It also begs to reason why Vader would even scream over his mechanical arm getting severed. Maybe there were nerves connected during Vader’s suit construction or something?
I am sure the robot parts are connect to nerves. When Luke gets his mechanical hand he showed reactions to getting poked.