姿态控制用微推进系统是微小卫星，尤其是10公斤以下的微卫星研究的薄弱环节。作为基于MEMS的微推进系统的一种，微胶体推进系统具有高比冲、能够产生连续可控的微牛级的推力等突出的特点。围绕微胶体推进系统，本论文主要研究电喷的喷射规律、微结构条件下发生电喷射的最低电压条件、微流量输送的关键器件微泵和微胶体推进器的结构设计和制造、以及高真空条件下微牛级推力的测试等关键性问题。本文以液体表面电荷的对流为研究对象，建立了以驰豫时间常数很短的液体作为工质的微胶体推进器在单喷射状态下电喷射的理论模型；从稳定系统能量的角度导出了微胶体推进器多喷射状态下的电流喷射模型。基于这两个关于喷射电流的理论模型导出了微胶体推进器推力和比冲预计的方程式。利用特殊参数的双曲面组近似微胶体推进器源极和抽取极的结构特征，基于拉麦方法导出了源极顶端电场轴向分量的最大值的估算方程，解决了复杂不对称微结构的静电场分布无法精确求解的问题；与复杂电极形状下的仿真分析相结合， 研究了源极高度、两极中心对准安装误差以及极间的距离对静电场分布的影响。在此基础上，得到了微推进器最低工作电压的理论估计公式。提出了基于体硅工艺的三层结构的微胶体推进器的设计方案和以湿法和干法腐蚀相结合为主要特征的工艺方案，制作了喷口内径在30～100微米、源极突起高度为80微米的微喷口及其阵列。将薄厚度的悬臂梁的振动模态的分析理论应用于微牛级推力测试，通过从悬臂梁振动的微位移中分离掉由悬臂梁自身振动引起的分量的方法实现了高真空条件下的微胶体推进器微牛级推力的测试。结果表明，微胶体推进器起始工作电压为1400伏特，能够输出微牛级推力和微牛秒级冲量，比冲大于125秒。本文还针对微胶体推进系统的要求设计和制造了压电致动微泵；通过对多种溶液的物理、化学性质的分析选定了重量比为30％的碘化钠/甲酰胺作为微胶体推进系统的工质。

Micro propulsion systems are crucial for the attitude control of micro-spacecrafts, especially those with the weight less than 10 kilograms. In recent years, many kinds of micro thrusters, based on different principles, have been developed using micro-system technologies. Among these micro thrusters, micro colloid thruster are getting more and more interests for its high specific impulse, continuous and controllable thrust in the order of mN. In this dissertation paper, several key technologies involved in the development of the micro colloid propulsion system were theoretically and experimentally investigated, which includes the laws of electrospraying, the prediction of the onset operational voltage of the thruster, the design and fabrication of core components such as the micro pump and the micro colloid thruster, and the characterization method of the performance of the thruster.The charge convection in a liquid surface with small relax time constant was first investigated, and a model was built for evaluating the liquid behavior in the phenomenon of cone-jet electrospraying. By the analysis on the energy of a stationery system, another model was built to describe a multi-jets. Based on these two modals, equations for predicting thrust and specific impulse of a micro colloid thruster were then derived. By simplifying the source emitter and the extractor of the micro thruster as two hyperboloids of two sheets of a set of equal-potential surfaces, a model for evaluating the maximum electric field strength between the two electrodes was set up and solved using Lamé method. The onset voltage for the operation of the micro thruster was then proposed based on the maximum field strength. The dependencies of the distribution of the electric field respectively on the surface of the source emitter, the height of the source emitter, mounting errors, or the distance between the source emitter and the extractor were also discussed based on the FEM analysis. Based on MEMS technologies, a prototype of the micro colloid thruster has been designed and fabricated by bulk silicon process. Dry etching and wet etching were employed as major fabrication methods. A micro-nozzles array, with the nozzle in the diameter of the 30-100mm and the height of 80mm was eventually fabricated.An experimental set-up was used to measure the performance of the micro-thruster. the Thrust in the order of μN produced by the thruster was transformed to the displacement of thin cantilever beam. After the noise signal caused by the free vibration of the cantilever beam itself was filtered, the Displacements of the cantilever beam, the measured thrust of the micro thruster can be obtained from the displacements of the cantilever beam. The experimental results showed that a thrust in the order of μN and an impulse bit in the order ofμN.s can be produced by a single emitter, with a starting working voltage down to 1400V and the specific impulse up to 125s. Under the requirement of the micro colloid propulsion system, a piezoelectric driven micro-pump was also developed in this paper. In this study, formamide doped with 30% NaI in weight was used as propellant.