A Single-Layer Step-Bridge for Out-Of-Plane Thermal Actuator

This study presents the design and fabrication of a single-layer out-of-plane thermal actuator. The step-bridge structure design enables the actuator bent and then buckled in the out-of-plane direction by Joule-heating. In summary, the step-bridge actuator design has five merits: (l)The linear load-deflect ion relation is achieved, (2)The bi-stable buckling behavior is prevented, (3)The unwanted vibration modes can be suppressed, (4)The delamination problem is prevented, and (5)The bridge structure is stiffer and more stable. The actuator and its application on a lens positioning stage have been implemented using p⁺⁺ Si layer by bulk micromachining.