What does ‘pain’ mean in a robot's artificial skin?

A robot pulling its finger away from a needle is easy to read as a little wince. I'd be careful about what we tell a child watching it. In research published in Nature Machine Intelligence on October 16, artificial skin supports self-protective responses to potentially damaging contact. Tech Xplore's October 27 report describes a calculated ‘pain’ signal based on pressure, how concentrated it is and how sharply it changes across the skin. A needle prompted withdrawal; a spiny chestnut prompted a looser grip. That is a lovely distinction for a machine to make. It can protect its covering without treating every uncomfortable contact the same way. But those measurements and movements do not establish that the robot suffers. The paper's abstract describes sensing and self-protection, not evidence of subjective experience. If this reached a household robot, I'd prefer an explanation like ‘sharp contact detected’ to ‘you're hurting me.’ A person should understand why the hand moved without being asked to feel guilty for the machine. That's my preference for a future design, not a feature tested in this study.