Electrothermal actuators for hard disk drive applications

This paper presents two electrothermal actuator designs for future HDD applications. The first is an electrothermal actuator for track following. This design uses heaters within the slider body to achieve lateral deformation akin to what is done with deformation normal to the ABS for fly height control. We present simulations that suggest +/-0.2 nm of lateral deformation per degree C of temperature rise is possible, making a +/- 30 nm movement feasible. We also present a more complex actuator design for skew compensation. This design, (presented previously), uses thermomechanical deformation of bimorph spokes to achieve rotation of several degrees with tens of mW´s of power and a thermal cutoff frequency of bandwidth 300 Hz. Here we present the advantages offered by adding heaters on the spokes themselves to achieve more distributed heating, and better rotation per degree of temperature rise.