3D tactile rendering based on bi (multi) stable SMA monolithic systems

Tactile interfaces are deformable surfaces that communicate information through the sense of touch. We propose a new concept for a tactile interface based on monolithic SMA actuators with integrated bi or multi stable structures. This concept allows the development of a new generation of tactile matrices with a high density of SMA micro actuators with high efficiency and low power dissipation. This paper addresses the design of a monolithic SMA micro actuator composed of two flat springs in an antagonistic configuration. Design considerations and first experimental results are presented. The heat transfer is minimized between the springs to avoid coupling effects which would lead to an efficient two-way actuator. The optimization design of the actuator which is covered in this work satisfies both thermal and mechanical specifications.