The Design,fabrication And Test Of Microthruster Based On MEMS Technology

With the advantages of low cost,small size,light weight,high integration and short manufacture period,micro/nanosatellites are quite suitable for the small space required and low cost satellites misson.Also because of the properties like light weight,limited space and low power capacity,the micro/nanosatellites can not equip the traditional chemical thrusters and regular electrical thrusters.As for the increasing development and growing maturity of micro-electro-mechanical-system(MEMS)technology,the high reliability and functional microthrusters,especially the cold gas and electro microthrusters,get a booming development to fulfill the requirement of micro/nanosatellites in changing flying attitude like altitude control,orbit keeping and orbit transfer.Despite this,so far,there are no unified conclusion over the characteristic and performance of sub millimeter thruster,particularly in the experiment analysis results.Setting in this technology,the paper is concerned with the microthruster based on MEMS technology,and conduct the research over design,fabrication and test of micro thrust and heating property.In this paper,a multi-physics coupling simulation model is established over MEMS thruster.In addition,an optimal design is proposeed over micro thrust,specific impulse efficiencies and heating performance based on that model.According to the simulation results,a micro thruster is fabricated based on MEMS technology processing and conduct micro thrust test and heating performance test.Work in this paper includes:(1)Theoretical design,simulation optimization and performance test of small scale supersonic nozzleAfter the propellant selection,the flow structural parameters are estimated based on the ideal entropy flow,and the multi-physics coupling simulation model is established.The two dimensional viscosity-heat coupling simulation is completed,and the structural parameters are analyzed and optimized.After the micro propulsion supply and test system building,the designed test and data processing algorithm for that system are completed,and the results are processed.In the end,the orthogonal analysis over structural parameters,pressure sensitivity analysis and the influence of heating performance of the micro thruster.(2)Process exploration and fabrication of MEMS micro thrusterBased on the simulation results,the scheme design of MEMS micro thruster is carried out.Subsequently,according to the scheme design the process design is been done,and the MEMS micro thruster is fabricated through a variety of MEMS process.In the end,the process parameters are fixed,which lays the foundation for the mass production of the thrusters with excellent quality and stability.(3)Simulation optimization and performance test of sub micron mutilayer thin film microheaterThe sub micron mutilayer thin film microheater is analyzed and optimized base on multi-physics coupling simulation.After the stationary and transient test of the microheater based on infrared image,the test results are analyzed through the designed algorithm.Two different structure of sub micron mutilayer thin film microheater’s perfromance are tested over both stationary and transient,and the guidance of this microheater applicated in MEMS micro thruster is given.The paper investigates the MEMS micro thruster based on MEMS technology on theoretical,numerical and experimental front.The work in the paper introduces multi-physics coupling simulation into design and analysis in MEMS thrusters to improve the reality of simulation,which enjoys great significance both for theoretical study and engineering practice.