The idea of sealing the drive [8] and controlling the atmosphere within has long been seen as an inevitable evolution of HDD technology. There are numerous potential advantages such as immunity to altitude changes and reduced susceptibility to corrosion, but the ‘holy grail’ has always been a helium-filled drive. Helium offers several advantages arising from its very low density and very high thermal conductivity. It takes much less power to run the spindle; cooling of the VCM and preamp is greatly improved; and temperature differentials within the drive almost disappear. The most important gain is from the reduction of internal turbulence and buffeting of the actuator and disks. This dramatically improves the track-following stability and accuracy. Helium, however, is monatomic, fast moving, and non-reactive, and has a tiny atomic radius—all contributing to its reputation as the ultimate ‘escape artist’. Successful helium containment can certainly be achieved, but commercial implementation of sealed-drive technology still awaits an economically attractive solution.