| With the development of MEMS, the requirement for energy and multiple functions has been an important aspect during application. Nano composite energetic materials have become an extensive research subject due to these advantages including higher energy density, faster energy release, and shorter ignition time. It is necessary to integrate nano composite energetic materials with MEMS to meet these higher performances. Nano thermite, which is the most significant kind of nano composite energetic materials, has become the focus of this field for its simpler preparation, higer energy density, and faster release rate. There is the fact that the compatibility with MEMS should be considered and resolved with nano thermites applied to MEMS. There are a number of methods for making nano thermites, such as powder mixing, sol-gel method, layered vapor deposition, self-assembly and arrested reactive milling. Compared to other methods, it is simple and safe to control the composite compotents size using sol-gel method. In this paper the energetic device was fabricated with the help of sol-gel method making nano thermites in the micro pore of Si-MCP. Not only the fabrication and filling of nano thermites but also the fabrication process of Si-MCP was well compatible with MEMS, which made this energetic device could be applied to MEMS field. The detail process was as follows:The Si-MCP was prepared by photoelectrochemical (PEC) process, then making nano thermites Fe2O3/Al in the micro pore of Si-MCP through the sol-gel method. Finally the energetic device was gotten. The energetic device was characterized by SEM, EDS and TG-DSC. Meanwhile, to improve the heat release of energetic devices and increase the gas producing, Si-MCP was filled with organic energetic materials including RDX, HNS, picric acid lead via sol-gel method and dropping under negative pressure, and the energetic devices were also characterized by SEM, TG-DSC. The results shown that:1) Nano thermites Fe2O3/Al with five different molar ratios had been gotten by sol-gel method. The results of SEM and TEM both showed that nano Al was distributed uniformly in the composites system. The experiment results of TG-DSC demonstrated that the best molar ratio for nano thermites Fe2O3/Al was1:3.2and the total heat release was875.87Jg-1. The products after TG-DSC experiment were investigated by XRD, the fact that the thermite reaction between Fe2O3and Al occurred was certified by the formation of Fe.2) The Si-MCP was prepared via photoelectrochemical (PEC) process, the results of SEM showed the microstructure of Si-MCP was periodic and the surface has a regular square morphology, whose pore diameter was about4-5μm. All the microchannels were aligned orderly, paralleled to each other and there were little impurities in the each channel.3) The results of SEM and EDS for Si-MCP energetic device indicated the micro pore of Si-MCP had successfully been filled with nano thermites. The results of TG-DSC about Si-MCP energetic device showed the exothermic reaction started at689.42℃with total heat release being equal to114.42J g-1, which was lower that theoretical value. The reason for this phenomenon was that the quantity of nano thermites in the mirco pore Si-MCP is small. The results of DSC for RDX/Si-MCP energetic device showed that the reaction began at634.42℃, and the total heat release could reach823.22J g-1, which is higher than that of Fe2O3/Al Si-MCP energetic device and HNS/Si-MCP energetic device. The total heat of picric acid lead/Si-MCP energetic device was796.05J g-1. The above work has opened up a new way for preparation of energetic device, increasing functions of MEMS energetic devices. In future efforts in improving the energy density of energetic device will further promote development of this technology. |
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