Design and Simulation of a New Type of Electrothermal Micro-flat Lens Unit Structure

Based on the principle of electrothermal actuator, this paper designs a new type of electrothermal micro-flat lens unit structure to micro-adjust the phase of the transmitted beam. This structure mainly consists of a micro-flat lens and four symmetrical S-shaped actuators. The lens can realize two motion states, vertical displacement and tilting, by applying voltages to different actuators. Symmetry of actuators avoids the influence of ambient temperature on the tilt of the lens. A positive hexagonal shape of lens provides a foundation for relevant dense array structure with a high filling factor. The natural frequency, displacement and tilting of the structure are simulated by COMSOL. Results show that the electrothermal micro-flat lens unit structure can work normally lower than 5806.8 HZ, and get a large vertical displacement of 166 µm and a tilt of 12° at a low driving voltage of 1.8 V.