Active NIRT: Hierarchical Manufacturing and Modeling for Phase Transforming Active Nanostructures

这项拟议的研究是为了响应活跃的纳米结构和纳米系统倡议，NSF 06-595，NIRT类。在纳米医学、纳米电子学、空间探索、国土安全和国防等领域的广泛应用需要能够驱动和传感的有源纳米结构和纳米系统。来自德克萨斯农工大学和佐治亚理工学院的联合PI集成团队建议，作为一项联合研究工作，在相变磁性形状记忆合金(MSMA)的分层制造和建模方面，一个综合的跨学科计划。技术：该提案的主要目标是建立一个层次化的框架，将MSMA纳米层的制造与纳米线的挤压结合起来。然后，这些单片和混合纳米线将被用于制造光纤，通过同轴电纺，作为可以被温度、应力和远程磁场激活的装置。纳米制造的第一个层次将集中在薄膜上，由纳米到微米尺寸的传统形状记忆合金(SMA)层、磁性材料和使用磁控溅射的MSMA组成。然后，薄膜将作为纳米线制造的先驱，使用成本效益高的液压挤压技术。更高层次的纳米制造将包括使用一种新型的同轴电纺丝，其中纳米线将在选定的基质(如二氧化硅)中排列，以制造生物传感器、遥控纳米/微执行器和活性介孔延性膜。为了支持纳米制造的努力，选择性多尺度模拟将涉及原子模拟以解决纳米尺度上的相变现象，以及基于微观结构机理的连续统级本构模型以解决纳米结构和纳米器件行为的功能。非技术性：拟议的研究将尝试开发一种具有形状记忆和磁性相结合的纳米线的多层次制造方法。这种分层的制造方法将得到并行的多尺度建模工作的辅助，也将得到多尺度最先进的表征技术的帮助。这些独特的多功能纳米线将被用于制造生物传感器，使用一种新的同轴静电纺丝方法。这项拟议的研究具有重要的科学意义，因为它将通过分级纳米制造揭示晶体长度尺度上发生的纳米级现象对更大规模功能的影响。这项研究还将为新型多功能材料和器件带来结构合理的分层制造方法和结构，用于工程应用中的传感器和执行器，促进微执行器、生物传感器、阀门和活性介孔结构的设计。这些研究产生的知识可能会彻底改变有源纳米和微米级系统和部件的设计，这些系统和部件能够经历非常快的可逆变形，并显示出高致动、传感和良好的发电特性。拟议的项目活动将包括开发多功能材料的教学模块，以便纳入本科课程；通过德克萨斯农工大学和佐治亚理工学院之间的夏季合作交流计划，丰富研究生和本科生的研究经验；开发一门关于活性薄膜、纳米线和活性纳米结构的研究生课程；通过参与地区少数族裔服务大学，让未被充分代表的群体参与进来；并在中学教育项目的教材中注入实验室示范模型，该项目将与德克萨斯A&AMP；M新建立的NSF纳米级本科教育(NUE)计划相协调。

This proposed research was submitted in response to the Active Nanostructures and Nanosystems initiative, NSF 06-595, category NIRT. Active nanoscale structures and nanosystems capable of actuation and sensing are needed for a wide range of applications in nanomedicine, nanoelectronics, space exploration, homeland security and defense. An integrated team of co-PIs from Texas A&M University and Georgia Tech proposes, as a combined research effort, a comprehensive interdisciplinary program in hierarchical manufacturing and modeling for phase transforming magnetic shape memory alloys (MSMA). Technical: The main goal of the proposal is to establish a hierarchical framework that will combine the fabrication of MSMA nanolayers with the extrusion of nanowires. These monolithic and hybrid nanowires will then be used in the fabrication of fibers, by coaxial electrospinning, to be used as devices that can be activated by temperature, stress, and remotely by magnetic field. The first level of nanomanufacturing will focus on thin films, composed of nano to micron size layers of conventional shape memory alloys (SMA), magnetic materials and MSMA using magnetron sputtering. Thin films will then serve as precursor for nanowire fabrication by using a cost effective hydraulic pressure extrusion technique. The higher level nanomanufacturing will involve the use of a novel coaxial electrospinning whereby nanowires will be aligned in selected matrices such as silica for the purpose of making biosensors, remotely controlled nano/micro actuators, and active mesoporous ductile membranes. To support the nanomanufacturing effort, selective multiscale modeling will involve atomistic simulations to address phase transformation phenomena at nanoscale, and microstructural mechanism-based continuum level constitutive models to address the functionality of the nanostructures and nanodevice behavior. Nontechnical: The proposed research will attempt to develop a multilevel fabrication methodology for nanowires with combined shape memory and magnetic properties. This hierarchical fabrication methodology will be assisted by a parallel multiscale modeling effort, and also by multiscale state-of-the-art characterization techniques. These unique multifunctional nanowires will be utilized in the manufacturing of biosensors using a novel coaxial electrospinning method. The proposed research is scientifically significant because it will reveal the effect of nanoscale phenomena occurring at crystallographic length scales on larger scale functionality through hierarchical nanomanufacturing. The proposed research will also result in well-structured hierarchical fabrication methodologies and architectures for new multifunctional materials and devices to be used as sensors and actuators in engineering applications, facilitating the design of micro-actuators, biosensors, valves and active mesoporous structures. The knowledge generated from these studies could revolutionize the design of active nano and micro-scale systems and components capable of undergoing very fast reversible deformations, and exhibiting high actuation, sensing and promising power generation characteristics. The proposed project activities will include the development of teaching modules in multifunctional materials for incorporation into undergraduate courses; enrichment of graduate and undergraduate research experiences through summer collaborative exchange programs between Texas A&M and Georgia Tech; development of a graduate course in active thin films, nanowires and active nanostructures; involvement of underrepresented groups through participating regional minority serving universities, and injection of laboratory demonstration models in educational material for secondary educational programs, which will be coordinated with the newly established NSF Nanoscale Undergraduate Education (NUE) program at Texas A&M.