My artificial intelligence Asa H notices when erratic servo rotation occurs (due to worn and/or stripped gears) and unsteady signals are seen from such things as electrochemical sensors. These give Asa a definition for (concept of) "old age."
I have some old BASIC stamp and Lego RCX robotics hardware but most now is Lego NXT or newer. With Asa we can hope to replace all of his aging components, unlike with humans. I hope that artificially conscious agents will suffer less than humans, not more. (Contrary to T. Metzinger's, The Ego Tunnel, Basic Books, 2010)