| Along with the rapid development of modern optics and optoelectronic technology, photoelectronic equipment and devices have made significant changes. Miniaturization and intellecturalization have been the main building blocks for realizing the change. A new subject, micro-optics, was born. Micro-optical devices have wide application prospects almost in all engineering applications, especially in the area of defense science and technology industry. However, actual production quality lags far behind theoretical design ability. Manufacturing problem becomes a great barrier to its development and applications. Consequently, fabrication technology aiming at micro optical devicess of high efficiency, low cost and volume production has become one of important research domains in the world. As one of precision fluid dispensing techniques, micro-droplet jetting indicates a fabricating process which is used to precisely dispense functional and/or structural materials on a substrate in digitally defined locations. Being a material increase manufacturing (MIM) technology, it belongs to the domains of direct writing technology. It can not only simplify processing steps and improve productivity, but also lower consumption of energy or raw materials. Furthermore, it posess better environmental compatibility. As an additive fabrication technique of data-driven type, it can directly manufacture complicated 3D structures. The progress of the technology meets the needs of environmental protection, material utilization and technical flexibility for the development trend of modern manufacturing process.A pneumatic diaphragm-based Drop-on-Demand (DOD) microdroplet jetting technology with independent intellectual property right is presented in this dissertation. Combining the advantages of piezoelectric and pneumatic generators, the pneumatic diaphragm-based DOD generator has the following key features:simple construction, convenient operation and maintenance, large driving power and robust. The self-developed pneumatic diaphragm-based DOD system is set up and used to complete the studies on principle and fabrication technique of microdroplet jetting. And the main contents are summarized as follows:Firstly, the mathematical model of jetting process of the pneumatic diaphragm actuator is carried out by unsteady Bernoulli equation and mass conversation equation based on analysis of diaphragm modal, load-deflection characteristics and fluid-diaphragm coupling. The relationships between the input pneumatic pulse and diaphragm deformation, internal pressure of chamber, nozzle and throttle outflow velocity were attained. The model and calculation results may be used as theoretical basis for structure and control parameters optimization of jetting generator.Secondly, the pneumatic diaphragm-based DOD microdroplet jetting system is set up, including several units:the generator, solenoid valve driving circurt, pressure control unit, temperature controller, the 3-dimensional working platform and the in situ vision subsystem. The research emphasises on the controllable making method of glass nozzle and the in situ vision system. Delayed external trigger is put to stir up the CCD to capture images. The droplet dimension, flying distance and velolcity can be caculated from these images through digital image processing.Thirdly, in order to discuss the mechanism to form microdroplet, the formative process of primary droplet and satellite droplet is simulated using VOF model by Fluent 6.3. The performance of the generator was studied by adjusting the structure and control parameters. Furthermore, the influence of fluid properties on the droplet ejection process was experimentally investigated.Next, the post-impact micro droplet deformation processes, from spreading and recoiling, to either oscillation of rebound are described in detail and an analytical expression of the energy state at each discrete stage is presented. Bouncing criterion coming from energy conservation can be used to determine the deformation state after impacting through initial condition of microdroplet. Furthermore, the post-impact processes of different physical properties microdroplets on substrate of different wettability were obtained. The influence of micro droplet characteristics and the interaction of micro droplet and substrate on post-impact process afford key theoretical and experimental proof for jetting technology.Finally, micro-lens arrays with 75-400μm in diameter, were produced by UV curing glue. Through testing 9x9 micro-lens array with diameter of 333.28μm, the results indicated that the variation of diameter is about 1.6%, surface roughness is about 0.243nm, the calculated mean focal length is aout 389.07μm, the uniformity error is 1.6%, the measured mean focal length by Porro reticle is 482.04μm, the uniformity error is 1%. The experimental results demonstrate that the jetting technology is a quite potential and very flexible manufacture method for micro-optical devices.In addition, a micro hot embossing technoloty suitable for polymer micro-optical devices replication methods are also studied. Micro grating is fabricated by contact-type embossing method, while micro-lens array is fabricated by contactless embossing process. The results indicate that micro hot embossing technology is an excellent manufacture way in batch quantity with high-efficiency and low cost and shows a good application prospect.
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