Artificial pain sensors could help robots avoid damaging themselves. It may sound ridiculous and even make someone think about a joke, but it is an interesting concept. The first thing that came to my mind is that this technology may improve prosthetics.
It sounds amazing living without ever feeling pain. However, Congenital Insensitivity to Pain is a serious condition that can lead to premature death simply because who is affected is not stopped by injuries. Anecdotally, who is affected could lean on a stove and severely burn themselves.
Prosthetics able to signal pain to the owner would be a game changer.
For robots, my first thought went to dystopian sci-fi. What if we bake the fear of pain in AI and the AI becomes dangerous to humans for self-preservation? That is basically the plot of Blade Runner, in which the androids don’t want to die and rebel against their creators.