CAREER: Engineering Designer Composite Materials -- Magnetically Controlling Filler Alignment of Oblate Spheroids in Novel Thermoset Metamaterials

CBET-1652958 PI：步行者，特拉维斯W.这个职业生涯奖的目标是开发一个综合的教育和研究计划，重点是创造新型超材料，这是先进的复合材料，表现出通常不会在自然发生的材料中发现的属性。 超材料通常是通过将填料颗粒添加到基底（例如聚合物材料）来产生的。 如果可以精确控制填料颗粒的尺寸、形状和取向，则可以以新颖的方式定制材料的宏观性质，例如其强度或刚度。 该项目将使用磁场来控制填充物颗粒，例如已在初步实验中使用的磁性微盘。该项目将开发理论模型，以帮助确定工程复合材料的新策略。实验和理论将验证这样的假设，即通过控制亚微米填料颗粒的排列时间和复合材料的固化，可以在亚微米长度尺度上设计超材料。 该项目的结果可以通过找到在复合材料中改变空间特性的方法来帮助推进增材制造。 该项目将包括为K-12和大学参与者开发新的模块和实践活动，新课程名为“通过实践服务学习探索物理的魔力”。"此外，研究小组将利用实验室的3D打印能力，为高中学生和教师开发3D建模和打印工作坊。复合超材料将通过排列二维磁性颗粒来制造，即，圆盘，在牛顿流体中，同时控制颗粒的质量分布中心。颗粒的尺寸、形状、取向、浮力、磁化率和浓度均预期影响排列动力学和中断的形成，例如颗粒链，这可能导致材料中不希望的异质性。 实验将涉及使用一种新的磁镊子装置，用于研究使用旋转磁场的对齐。 在各种磁场条件下的两粒子相互作用将被检查。 然后，将测量胶体悬浮液的流变特性以确定颗粒形状和取向的影响。 战略将确定磁性排列填料颗粒，同时防止链形成。 然后，将开发一个装置，系统地分析在取向和聚合的块体各向异性复合材料的控制参数。 在体积力存在下，粘性流体中颗粒运动的基于连续介质的理论描述将有助于解释实验数据，为填料颗粒的设计提供见解，并指导先进复合材料的精密工程。 具有精确排列的填料的纳米复合材料将为创造先进的生物材料、光学、电磁和膜技术提供新的创新机会。

CBET - 1652958PI: Walker, Travis W.The goal of this CAREER award is to develop an integrated program of education and research focused on the creation of novel metamaterials, which are advanced composite materials that exhibit properties not usually found in naturally occurring materials. Metamaterials are often created by adding filler particles to a substrate, such as a polymeric material. If the size, shape, and orientation of the filler particles can be precisely controlled, then macroscopic properties of the material such as its strength or stiffness, can be tailored in novel ways. This project will use magnetic fields to control filler particles, such as magnetic microdisks that have been used in preliminary experiments. The project will develop theoretical models to help identify novel strategies for engineering composite materials. The experiments and theory will test the hypothesis that metamaterials can be designed on the sub-micron length scale by controlling the alignment time of submicron filler particles and the solidification of the composite. Results from the project could help advance additive manufacturing by finding ways to vary properties spatially through a composite material. The project will include development of new modules and hands-on activities for K-12 and college participants in a new course titled, "Exploring the Magic of Physics via Hands-on Service Learning." Furthermore, the research team will leverage the use of 3D printing capabilities in their laboratory to develop workshops on 3D modeling and printing for high-school students and teachers.Composite metamaterials will be fabricated by aligning two-dimensional magnetic particles, i.e., disks, in Newtonian fluids while controlling the center of mass distribution of the particles. The size, shape, orientation, buoyancy, susceptibility, and concentration of the particles are each expected to influence alignment dynamics and the formation of disruptions, such as the particle chaining, which could lead to unwanted heterogeneity in the material. The experiments will involve the use of new kind of magnetic tweezer apparatus for investigating alignment using a rotating magnetic field. Two-particle interactions under various magnetic field conditions will be examined. Then, the rheological properties of colloidal suspensions will be measured to determine influences of particle shape and orientation. Strategies will be identified for magnetically aligning filler particles while preventing chain formation. Then, an apparatus will be developed to systematically analyze control parameters during alignment and polymerization of bulk anisotropic composites. Continuum-based theoretical descriptions for particle motions in viscous fluids in the presence of body forces will help interpret experimental data, provide insight into the design of filler particles, and guide precision engineering of advanced composites. Nanocomposites with precisely aligned fillers will offer new opportunities for innovation in creating advanced biomaterial, optical, electromagnetic, and membrane technologies.