Creating large out-of-plane displacement electrothermal motion stage by incorporating beams with step features

Realizing out-of-plane actuation in micro-electro-mechanical systems (MEMS) is still a challenging task. In this paper, the design, fabrication methods and experimental results for a MEMS-based out-of-plane motion stage are presented based on bulk micromachining technologies. This stage is electrothermally actuated for out-of-plane motion by incorporating beams with step features. The fabricated motion stage has demonstrated displacements of 85 µm with 0.4 µm (mA)⁻¹ rates and generated up to 11.8 mN forces with stiffness of 138.8 N m⁻¹. These properties obtained from the presented stage are comparable to those for in-plane motion stages, therefore making this out-of-plane stage useful when used in combination with in-plane motion stages. (paper)