Metallic thin film composites with shape memory alloys for microswitches and tactile graphical displays

Issue title: E-MRS Fall Meeting 2005

Article type: Research Article

Authors: Vitushinsky, Roman^a | Khelfaoui, Fadila^a | Schmitz, Sam^a | Winzek, Bernhard^a

Affiliations: [a] Center of advanced european studies and research caesar, Bonn, Germany. E-mail: winzek@caesar.de, vitushinsky@caesar.de

Abstract: A new mechanism to switch thin film actuators between two stable states has been developed. Bistable membrane switches can be realized by snap-dome shaped metallic foils which are coated on opposite surfaces with Ti(Ni,Cu) and (Ti,Hf)Ni respectively whereby the narrow hysteresis of Ti(Ni,Cu) is within the broad one of (Ti,Hf)Ni. If both SMAs are martensitic or both are austenitic, they apply similar forces on the intermediate foil and the shape of the membrane remains constant. However, if one of them is austenitic and the other one martensitic, the austenitic one determines the curvature of the membrane. Switching is possible by two different heat pulses. Therefore, energy is only required to change the state of the membrane. The new mechanism is described and first successful processing steps are presented. The mechanism allows the fabrication of microswitches and tactile displays.

DOI: 10.3233/JAE-2006-720

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 23, no. 1-2, pp. 113-118, 2006