Understanding Instabilities of TFC Femto-Slider and Pico-Slider via Surface Force Theory

We formulated the surface pressure of a disk surface that consists of three layers of diamond-like-carbon (DLC) as well as bonded and mobile lubricants based on the asperity adhesive contact theory. We demonstrated that this surface force could well evaluate the touchdown behaviors of a thermal fly-height control (TFC) slider. This theory shows that the touchdown behaviors of a current TFC femto-slider are mainly governed by the asperity meniscus force rather than the van der Waals force (vdW). However, it is shown that the static instability of a pico-slider was generated from the vdW force. Moreover, it is estimated that the dynamic instability of the pico-slider was mainly caused by the meniscus force rather than the vdW force. This surface force theory can allow us to understand consistently various phenomena of slider dynamics.