I would never have guessed how much thermal expansion had to be compensated for in modern hard drives, I would have assumed they were built such that no degree of precision that required accomodating changes in physical parameters was attempted, and/or that materials science had found an ideal set of alloys for the case, the platters, the magnets, arms etc, that all behave in a predictable way under a given thermal map, so that addressing the surface was nearly always a deterministic process.

Have there been attempts to use active cooling/heating (i.e. thermal sensors combined with piezoelectric effect elements embedded in the housing) to maintain a precise, consistent reference internal operating temperature, as a means of eliminating the need to accomodate thermal-induced drift in tolerances?