Artificial Materials: Fabrication and Property Evaluation

9972620哈洛伦人造材料有可能成为一类具有前所未有性能的新型工程材料。人造材料是一种精心设计的结构，建造在非常精细的尺度上。它由一种或几种普通物质组成，按照复杂的设计排列，从而产生独特的宏观性质。人造材料的设计者承诺“预先确定”的性能。从理论上讲，他们展示了如何选择一个特定的属性张量，并设计一个结构来精确地显示这些属性。这一概念在材料科学领域具有突出的潜力，因为它提供了从普通物质中获得的独特而有价值的新型特性。然而，这种潜力尚未在物理上得到证明。最近，优化设计领域的几位研究人员利用拓扑优化技术，设计出了具有优异性能的人工材料，如零热膨胀或非常高的压电性能。在这个高风险/高回报的项目中，PI将与这些设计师合作，用传统陶瓷制造它们的结构，评估它们的性能，并将实验与理论进行比较。最佳设计的材料是固体和空隙的精细阵列，这需要独特的制造方法，可以形成亚毫米的特征。由PI开发的一项新技术，微加工共挤出，将用于从50微米尺寸范围内的二维设计中生产人工材料。其他制造技术也将被使用：间接陶瓷立体光刻技术用于生产300微米尺寸范围内的三维设计，直接陶瓷喷墨沉积技术用于100微米尺寸范围内的设计。陶瓷-空气复合材料将从PI的合作者那里获得最佳设计，然后确定压电和弹性性能，并与理论预测进行比较。利用陶瓷填充聚合物复合材料制备零热膨胀人工材料，并对其热弹性性能进行表征。该计划的目标是探索拓扑优化优化设计在工程材料中的实际应用，将基于图像的设计技术扩展到材料加工中，并创造独特的压电和热弹性材料。人工材料的概念来自计算设计界。由于制造上的主要挑战，这种类型的材料尚未可用。PI建议使用最先进的陶瓷加工技术，从合作者那里获得设计，以执行这个多学科项目。这一努力将使材料科学更接近“设计材料”的目标

9972620Halloran'Artificial Materials' could become a new class of engineering materials with unprecedented properties. An Artificial Material is a designed structure, built on a very fine scale. It consists of one or several ordinary substances arranged according to a sophisticated design that leads to the unique macroscopic properties. The designers of Artificial Materials promise "pre-determined" properties. They have shown, theoretically, how to choose a particular property tensor, and design a structure that will display exactly those properties. This concept has outstanding potential for Materials Science, since it offers new types of unique and valuable properties, obtained from ordinary substances. However, this potential has not been demonstrated physically. Recently several researchers in the field of Optimal Design, using techniques of Topology Optimization, have designed Artificial Materials that are predicted to have outstanding properties, such as zero thermal expansion or remarkably high piezoelectric properties. In this high-risk/high-payoff project, the PI will collaborate with these designers, and fabricate their structures from conventional ceramics, evaluate their properties, and compare experiment with theory. Optimally Designed materials are fine scale arrays of solid and void, which require unique fabrication methods that can form sub-millimeter features. A new technique developed by the PI, Microfabrication by Co-Extrusion, will be used to produce the Artificial Materials from two-dimensional designs with features in the 50-micron size range. Other fabrication techniques will be used as well: Indirect Ceramic Stereolithography to produce three-dimensional designs with features in the 300-micron size range, and Direct Ceramic Inkjet Deposition for designs in the 100-micron size range. Ceramic-air composites will be fabricated from Optimal Designs obtained from the PI's collaborators and then the piezoelectric and elastic properties will be determined and compared to theoretical predictions. Artificial Materials with zero thermal expansion will be also be fabricated, using ceramic-filled polymer composites, and their thermoelastic properties will be characterized.%%%The objective of the program is to explore the practical application of Optimal Design by Topology Optimization to engineering materials, extend Image-Based Design techniques to materials processing, and create unique piezoelectric and thermoelastic materials. The concept of Artificial Materials came from the computational design community. This type of material are not yet available because of the major challenge in fabrication. The PI proposes to fabricate them using state-of-the-art ceramics processing techniques from designs obtained from his collaborators to perform this multidisciplinary project. This effort will bring materials science closer to the goal of "materials by design."***