An electro-thermal SU-8 cantilever micro actuator based on bimorph effect

An electro-thermal SU-8 cantilever micro actuator with large vertical motion at low voltage is presented in this paper. It is lower in voltage due to employing SU-8 as functional material because of its high coefficient of thermal expansion. A finite element simulation was utilized to determine the optimal parameter. Windows in the center of cantilever can reduce internal residual stress. And we also added a nickel matrix on surface of support base to enhance bonding force between supportive base and driving section. Then actuators were obtained through Micro Fabrication Technology. Finally the Scanning-electron microscope and WYKO NT1100 optical profiling system demonstrated that the electro-thermal actuator possesses a high quality cantilever. Its stiffness is relative large that is sufficient for application in Micro device proved by Bonding Tester. With applied voltage 0.5V the electro-thermal actuator can generate a vertical displacement of 42.9μm.