Fabrication of thin film metallic glass (TFMG) pipe for a cylindrical ultrasonic linear micro-actuator

Thin film metallic glass (TFMG) is characterized by high strength and a high elastic limit due to its amorphous nature, and the high glass formability of palladium-based (Pd-based) metallic glass allows the formation of large structures. With all of these properties, TFMGs are considered to be ideal candidates for micro-electromechanical systems (MEMS) and 3D micro-forming. In this paper, a hollow pipe structure made of Pd-based TFMG applied on a PZT pipe is introduced for use in a cylindrical ultrasonic linear micro-actuator (CULMA). The fabrication process of CULMA using a rotating sputtering system is presented. Using the PZT pipe as a vibration generator, the TFMG is forced to vibrate, and the vibration property is measured. From experiments, the stiffness of the TFMG pipe is confirmed, and the annealing influence of the fabrication process on the stiffness is discussed.