NIRT: Mechanics of NanoTurfs: Multiscale Modeling, Experiments and Characterization

纳米结构的最新发展揭示了一类由无序缠绕的结构单元(纳米线、纳米带、纳米管)形成的泡沫状纳米结构具有特殊的电磁、热和光学性能。这种无序的集合体被称为草皮。应用包括热开关、平板显示器、硬盘驱动器以及化学和生物传感器。尽管机械性能通常不是草坪的主要服务特征，但它们仍然是至关重要的。无论应用如何，TURF经常承受机械载荷，如热开关中的使用载荷，或意外接触载荷。在外力变形下，草皮的纳米拓扑结构发生变化，进而影响所有其他有效特性：电、热、光、传感和渗透性。我们将开发一种综合的方法来解决这个问题：多尺度建模、纳米机械实验和纳米结构表征，目标如下：根据单个单元的物理和几何属性以及它们在组装中的集体行为，理解和量化作为材料的草坪的行为。纳米尺度表征方法的发展，揭示了纳米结构的相关参数。该项目的实际技术影响是，结果将使针对传感器、热开关和其他设备的特定应用而量身定做的纳米草皮的合理设计成为可能。该计划的REU部分是精心构建的，包括评估方法，这些方法是在西苏里州立大学的教学中心开发和验证的。我们的试点学生指导计划将为研究生提供指导经验，这是博士毕业生需要的技能，但在大多数研究生项目中严重缺乏。

Recent developments in nanostructures have brought to light exceptional electromagnetic, thermal and optical properties of a class of foam-like nanostructures formed of disordered intertwined structural units (nanowires, nanobelts, nanotubes). Such disordered assemblies are named turfs. Applications include thermal switches, flat panel displays, hard discs drives, and, chemical and biological sensors. Although the mechanical properties are usually not the primary service characteristic of turfs, they are nevertheless of paramount importance. Irrespective of application, the turfs are often subjected to mechanical loads, either as service load as in thermal switches, or, as accidental contacts. Under externally forced deformation, the nano-topology of the turf changes, which, in turn, affects all the other effective properties: electrical, thermal, optical, sensing and permeability. We will develop an integrated approach to the problem: multiscale modeling, nanomechanical experiments, and, nanostructure characterization, with the following objectives: Understanding and quantification of the behavior of turfs as materials on the basis of the physical and geometrical properties of the individual units and their collective behavior in the assembly. Development of the nanoscale characterization methods that reveal the relevant parameters of the nanostructure. Practical technological impact of the project is that the results will enable rational design of nanoturfs tailored for particular application in sensors, thermal switches and other devices. The REU component of the program is carefully structured and includes assessment methods, developed and proven at the Center for Teaching and Learning at WSU. Our pilot student mentoring program will provide graduate students with mentoring experience a skill that PhD graduates need, but is sorely missing in most graduate programs.