Realization of SMA bimorph based composite mirror and actuator in a Stewart platform arrangement for beam steering application

Abstract

This work explores application of NiTi shape memory alloy (SMA) thin film composite structure in a parallel manipulator assembly for laser beam steering. A thin and lightweight NiTi SMA based mirror fabricated by thermal evaporation was manipulated with the help of four bimorph actuators assembled in a Stewart platform arrangement. By utilizing ArUco-based markers and computer vision techniques, the live position of the mirror was monitored. The program analyzed the position and tilt of three ArUco markers on the mirror to determine the tilt of the mirror on actuation. The maximum tilt of the mirror achieved was 28.76° with respect to x direction for an 8 V supply and 0.25 Hz frequency. Moreover, the position of the laser beam reflected from the micromirror was also studied. The maximum deflection achieved for the reflected laser beam was 1.01°±0.18° in x-direction and 0.42°±0.05° in z-direction. © 2025 Elsevier Ltd