Stress-modulated tilt actuator for tunable optical prisms

• Published in: Sensors and actuators. A. Physical. Vol. 266; pp. 328 - 337
• Main Authors: Leopold, S., Paetz, D., Sinzinger, S., Hoffmann, M.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.10.2017; Elsevier BV
• Subjects: Actuation; Actuator; Aluminum; Aluminum nitride; Beams (radiation); Deformation; Field of view; Fluids; Mathematical models; Mechanical properties; Micro-optics; Nitrides; Prisms; Stresses; Thermo-mechanical; Tunable; Tunable; Micro-optics; Thermo-mechanical; Aluminum nitride; Actuator
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2017.09.021

•Thermo-mechanical actuation can be used for a ±90° rotation of MEMS.•Aluminum nitride offers high displacement and driving force simultaneously.•Its geometry and residual stress define static and dynamic actuator properties.•Actuation enables droplet deformation and a prism with a tunable wedge angle. A tunable optical prism MOEMS based on the deformation of a liquid droplet is presented. An aluminum-nitride membrane is tilted by a novel type of thermo-mechanical actuator. The actuation principle is based on a thermo-mechanical modulation of the intrinsic stress in aluminum-nitride beams. Based on an analytical model, the key parameters of the actuator are optimized. Furthermore, the influence of the intrinsic stress on the actuator properties is investigated. These dependencies and the model are verified by mechanical characterization of samples. Operation in air and with ambient fluid has been confirmed. An image shift of 30 mm is found in a microscopic setup which corresponds to 19 % of the field of view.