Polymer Matrix Nano-Composites By Solid Freeform Fabrication

这项研究的目的是建立一个精确的固体自由形状制造工艺的知识库，该工艺可以产生完全用作梯度折射率透镜的聚合物基纳米复合材料。这种镜片是扁平的，而不是球面的。该项目将寻求确定通过喷墨沉积形成梯度复合材料的原理，以及使用光学透明的光敏化热固性树脂逐层光固化的原理，这些热固性树脂包含各种量的分散良好的纳米陶瓷颗粒。这项工作将包括选择和组合最合适的聚合物和陶瓷纳米颗粒组件，以及确定喷墨加工和固化的最佳条件。它还将把光学设计模型的使用与喷墨工艺结合起来。然后，设计输出将与打印机驱动程序相耦合。这对于制造在不同位置具有粒子浓度的层是必要的，以便产生所需的折射率梯度。如果研究成功，这项研究有可能引入一种经济的新型柔性光学制造。它将提供一个直接生产光学元件的平台，范围从独一无二的原型到完整的生产运行，而不需要研磨或抛光。聚合物梯度透镜可用于透镜系统，以减少25%至50%的元件数量，并显著减轻重量。由于它们将更加精确，它们还可以用于放松光学设计，降低对对准和制造误差的敏感性。定制能力和成本效益的结合可能会为这一工艺带来相当大的市场。此外，该计划中提出的概念将适用于制造其他纳米复合材料系统，特别是用粘土和碳纳米纤维增强的结构复合材料。使用相同的方法和更坚固的基质树脂体系，如航空航天环氧树脂，应该有可能制造出具有增强的弹性、强度和韧性特性的功能先进的纳米复合材料。

The objective of this research is to establish a knowledge base for a precision solid freeform fabrication process that creates polymer matrix nanocomposites that are fully functional as gradient refractive index lenses. Such lenses are flat rather than spherical. The project will seek to determine the principles behind forming gradient composites by inkjet deposition, and photocuring layer-by-layer from optically clear, photosensitized thermoset resins, which contain various amounts of well-dispersed nano-sized ceramic particles. The work will include selecting and combining the most appropriate polymer and ceramic nanoparticle components as well as determining the optimum conditions for inkjet processing and curing. It will also integrate the use of an optics design model in conjunction with the inkjet process. The design output then will be coupled with the printer driver. This is necessary for the fabrication of layers that have concentrations of particles in different locations in order to create the required refractive index gradients.If successful, the research has the potential for ushering in an economical new type of flexible optic manufacturing. It will provide a platform for direct production of optics ranging from one-of-a-kind prototypes to full production runs without the need for grinding or polishing. Polymeric gradient lenses can be used in lens systems to reduce the number of elements by 25 to 50% with significant weight reductions. Since they will be more accurate, they also can be used to relax optical designs, lowering the sensitivity to alignment and fabrication errors. The combination of custom capability and cost-effectiveness may result in a sizeable market for this process. Moreover, the concepts developed in this program will be applicable to fabricating other nanocomposite systems, particularly structural composites reinforced with clays and carbon nanofibers. Using the same methodology with more robust matrix resin systems, such as aerospace epoxies, it should be possible to fabricate functional advanced nano-composites with enhanced modulus, strength and toughness characteristics.