Shape memory alloy micro-actuator for handling of head gimbal assembly : manufacturing issues

Abstract

A Shape Memory Alloy micro-actuator has been designed and fabricated for handling of Head Gimbal Assemblyin hard disk drive industry. The micro-actuator consists of finger-like bimorph structures that will upward benddue to the difference in elongation of two materials at high temperature. The simulation results on deformedshape and exerting force are performed, and they reveal a feasibility of using SMA actuators for this kind ofapplication. Prototypes of micro-actuators are fabricated by two processes, i.e. sputtering and lift-off techniqueswith additional sacrificial and protective layers, and individual structure forming and sputtering techniques. Fewunsolved manufacturing issues occurred such as delaminating of material due to poor adhesion, oxidation ofstructures during the crystallization process, and tearing of fixed end of the structure.

Keywords : Head gimbal assembly, Shape memory alloy, Micro actuator, Micro fabrication, Nitinol