Ancient Engines by Michael Swanwick

A 1999 short story that was nominated for the Hugo award, "Ancient Engines" explores the idea of robots that are so self preserving that they actually purchase replacement parts for themselves in a bid to live forever. Non-Spoiler Summary In A Nutshell: The story begins as a drunken human insults a mech (robot) in a bar, and nearly dies because of it. As the triumphant mech makes to leave, he is invited to chat with an old man and his granddaughter - who question the mech's ability to live forever. They embark on a discussion of what it would take to create a robot that could live not just for a long time, but until the very end of the universe - several billion years from now. "What is it you want to talk about, Mr. Brandt?" His voice was audibly less hostile now, as synthetic counterhormones damped down his emotions. "Immortality. I found your ambition most intriguing." "What's to say? I take care of myself, I invest carefully, I buy all the ugrades. I see no reason why I shouldn't…