A Study Of New-type Micro Electro-thermal Actuator

Micro actuator is characterized as having great potential market and promising future application companying the development of Industry and Engineering. Micro electro-thermal actuator has advantages such as small size, light weight, cheaper and more stable process flow, compared with the traditional actuator. Its study is becoming a hot topic in Micro electrical and mechanical Systems research.A new-type micro electro-thermal actuator was presented in this study that was composed by cantilever, electrical circuit and base. Furthermore one kind of relay named magnetic-latched relay was explored based on the micro electro–thermal actuator. Theoretical computation and simulation were utilized to obtain optimal parameters and fabrication process to produce magnetic-latch relay. We also obtained some achievement in this study, such as the fabrication process of sacrificial layer, the fabrication process of high quality cantilever and three-mode magnetic-latch relayThe fabrication process of micro electro-thermal actuator was studied in the thesis. The fabrication processes employed new-type technique of fabrication of SU-8 and nickel. The thesis discussed the process in fabrication including coating, thermal treatment and expansion in etching solution. Also micro-plating technique was utilized to fabricate other structure like base and sacrificial layer. The fabrication process of the micro electro-thermal actuator has been studied. SU-8 is a kind of polymer which is higher in thermal expansion coefficient that can generate larger thermal tensile while also can produce unexpected deformation. Therefore its process was a critical step in entire fabrication process. A proper thermal treatment was carry out to modify its quality . A proper process of SU-8 cantilever was found through proper heat treatment. Besides fabrication process of SU-8 cantilever, some key parameters in fabrication process of nickel were discussed. We closed proper plating solution and plating current density to produce nickel with low internal residual stress in cantilever. These two key steps can dramatically impact the quality of cantilever. Finally micro actuator was fabricated successfully.The property of the micro electro-thermal actuator also was measured. The experimental results indicated that it was much more reliable to build a model that can be easily integrated in other devices and system. Its stiffness is enough for application in micro-relay. It can generate large displacement with low voltage and power consumption compared with other actuators. Based on the fabrication process of micro electro-thermal actuator, magnetic-latch relay also was fabricated tentatively.