NER: Using Surface Interactions and Continuum Models to Develop New Modes of Nano-Device Operation

本提案强调了四个利用表面相互作用的探索性纳米级设备。第一种方法是使用晶格注册来制造具有可调旋转和平移运动的纳米器件。其他人则利用纳米管的双稳定性（管/带），由表面粘附和原子尺度注册引起，以开发具有独特机械性能的纳米泵、恶习、开关和互连网络。为了确定这些装置的可行性，必须开发新的多尺度建模技术。这些模型必须包含从量子力学到结构学各个层面的重要物理学。pi的综合专业领域涵盖了整个范围，使他们能够仔细决定在每个尺度上必须包括哪些物理以及可以忽略哪些物理。Crespi博士新近开发的原子尺度注册和表面相互作用的潜力将被整合到Mockensturm博士利用所谓的Cosserat连续介质力学开发的非线性结构理论中。用分子动力学对这些装置进行理论研究是困难的，计算成本很高，使用连续统模型变得可行。无论这些推测设备的最终成功与否，新开发的建模技术将为进一步发现设备提供基础。随着尺寸减小到原子尺度，表面相互作用发挥了更重要的作用，以至于它们可以诱导新的和宏观上特殊的行为。在纳米结构的极限下，基本上每个原子都有可能在表面，特别是在碳基纳米结构中，它可以具有二维晶体结构（石墨，而不是金刚石）。因此，远程表面相互作用是纳米级器件的基本机制，在宏观世界中很少重要，通常被忽略。在纳米尺度上，范德华的相互作用使器件表现得好像涂上了一层厚厚的糖蜜。这些表面相互作用使碳纳米管具有两种稳定状态。最常见的是管状。然而，所谓的纳米带只是纳米管的另一种稳定（坍塌）状态。在这项研究中，研究人员将利用这种双稳态行为来开发纳米器件的新操作模式。具体来说，将研究具有独特机械性能的纳米泵、恶习、开关和互联网络的可行性。

Four exploratory nano-scale devices that take advantage of surface interactions are highlighted in this proposal. The first uses lattice registry to make nano-devices featuring tunable rotary and translational motion. The others use the bistability (tube/ribbon) of nanotubes caused by surface adhesion and atomic-scale registry to develop nano-pumps, vices, switches, and interconnected networks with unique mechanical properties. To determine the feasibility of these devices, new multi-scale modeling techniques must be developed. These models must incorporate the important physics at every level from quantum mechanical to structural. The combined areas of expertise of the PIs covers this full range, allowing them to carefully decide what physics must be included and what can be neglected at each scale. Dr. Crespi's newly developed potential for atomic-scale registry and surface interaction will be integrated into the nonlinear structural theories developed by Dr. Mockensturm using so-called Cosserat continuum mechanics. Theoretical studies of these devices which are difficult and computationally expensive using molecular dynamics become feasible using continuum models. Regardless of the ultimate success of these speculative devices, the new modeling techniques developed will provide a foundation for further device discovery.As sizes decrease to the atomic scale, surface interactions take on a more important role, to the point where they can induce novel and macroscopically peculiar behaviors. At the ultimate limit of a nanostructure, it is possible for essentially every atom to be at the surface, particularly in carbon-based nanostructures which can have a two dimensional crystalline structure (graphite, not diamond). Long-range surface interactions are, thus, a fundamental mechanism in nano-scale devices that are rarely important in the macroscopic world and typically ignored. At the nano-scale, van der Waals' interactions make devices behave as if they are coated with a thick layer of molasses. These surface interactions allow carbon nanotubes to have two stable states. The most commonly seen state is tubular. However, a so-called nano-ribbon is just another stable (collapsed) state of nanotubes. In this research the investigators will use this bi-stable behavior to develop new modes of nano-device operation. Specifically, the feasibility of nano-pumps, vices, switches, and interconnected networks with unique mechanical properties will be studied.