Design And Driving Characteristics Of Electrothermal Micro-actuator For Optical Fiber Alignment

Based on the MOEMS fuse safety system of laser initiation,a silicon-based electrothermal micro-actuator for optical logic control was designed.As the driving device of optical logic control,the silicon-based electrothermal micro actuator has lots of advantages,such as simple structure,small size,easy to integrate with the recoil safety mechanism,low driving voltage,high reliability and small electromagnetic interference,etc.,which satisfies the development trend of modern fuse.Through the construction of electrical-thermal-mechanical model and the research method of combining FEM with experiments,the design of micro actuator was conducted and the driving characteristics were investigated.The adopted research methods and obtained research results lay a foundation for the study of large displacement electrothermal micro-actuators,which has certain research and engineering significance.Based on the Joule effect and the thermal expansion effect,the driving principle of the electrothermal micro-actuator was illustrated.The electrical-thermal-force mathematical model was built,meanwhile,the temperature distribution equation and the end displacement expression of electrothermal actuator were acquired.The FEM software was used to conduct the simulation analysis of the multi-physics coupling of electro-thermal-force.The correctness of the electro-thermal-force model is verified by the steady-state FEM analysis of the actuator.In the transient FEM analysis,the dynamic characteristics of the actuator were analyzed,and the variations of the temperature,displacement and stress of the actuator with time were summarized.In addition,the variations of driving characteristics of the actuator during power off period were summarized by FEM analysis.Based on the DRIE method,the processing technology was developed and the principle prototype was produced,meanwhile,the package scheme and the resistivity measurement method of the principle prototype were proposed.The high overload environmental adaptability of the silicon-based electrothermal actuator in a fuze safety system was studied,and the impact resistance of principle prototype was tested with the hammer tester.The test results show that the actuator is capable of resisting high impacts of 11000 g and 1.1ms.The experiment platform of the driving characteristics of the electric actuator was built.The displacement of the electrothermal actuator is calculated by the method of image edge detection on MATLAB software.The experimental results show that the driving displacement is 57.83?m when the driving voltage is 12 V.Finally,the GUI program is written with the code of image edge detection method.Based on BP algorithm,a three-layer forward neural network model was established to optimize the geometric parameters of the electrothermal micro actuator.In the model,the hot arm width,cold arm width,cold and hot arm gap,and flexible arm length are used as the input signals of the neural network,and the end displacement is used as the output signal.Using the obtained FEM results by the MATLAB-ANSYS platform as samples data for training and testing neural networks.The trained neural network was used to predict the displacements of1000 actuators with different geometrical dimensions.In the end,the geometrical dimensions of one electrothermal actuator with the maximum displacement were obtained.Compared with the initial designed actuator,the drive displacement of the actuator is improved by 28.4% at 10 V after optimization.