Programmable Matter: Control Over Material Behaviour Through Scalable Self Assembly

可编程物质：通过可扩展的自组装控制材料行为

• 批准号: RGPIN-2014-04066
• 负责人: Puri, Ishwar
• 金额: $ 1.82万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=587581
• 关键词: Programmable; Matter; Control; Over; Material

Objects created today are primarily passive, i.e., they are unable to change their form or function after fabrication. One new approach to move beyond this severe limitation is to fabricate 3D objects embedded with functional artifacts that can change properties in response to external stimuli. Magnetostatic interactions among magnetic nanoparticles will be used to produce reversible self-assembled structures in a simpler and more flexible manner than available self-assembly methods. Starting from the same initial magnetic nanoparticle dispersion, variations in an externally applied magnetic field will provide a wide range of geometries that will be captured within composite materials after their surrounding liquid prepolymers are solidified. The different self-assembled microstructure geometries and their long-range organization will enable the design and fabrication of tunable bulk properties in these magnetic nanocomposites, such as their elastic moduli, magnetic susceptibility and remanance, and electrical and thermal conductivities. These properties will be correlated with specific microstructure assemblies, i.e., with the process control variables. This transformative approach will enable the design and fabrication of materials with a desired set of properties stipulated a priori. Theory, experiments and numerical simulations will all inform this investigation. This research will develop scaling laws correlating control variables to geometric features of self-assembled structures and validate them through experiments. Optical microscopy will be used for two-dimensional microscale imaging, X-Ray computed tomography for three-dimensional microscale imaging and transmission electron microscopy for nanoscale imaging. Numerical simulations will use Brownian dynamics providing Lagrangian tracking of individual particles coupled with magnetization dynamics using the Landau-Lifshitz-Gilbert equations to extend the investigation beyond experimental limits. The influence of microstructure on mechanical properties such as elastic moduli will be measured using atomic force microscopy in force volume mode and nanoindentation to record microscale heterogeneities, and tensile tests for determining its influence on bulk elastic moduli and anisotropy. Predictions of remanance will be validated by magnetic force microscopy and spin-polarized electron microscopy. Bulk magnetic properties will be determined using vibrating sample magnetometry. This research will enable design of the microstructure geometry to produce specific bulk material properties. It promises transformational applications spanning multiple disciplines, e.g., medicine (scaffolding methods in tissue engineering and intracellular actuators), device fabrication (MEMS and spintronics devices), and smart surfaces with tunable asperities (for lab-on-chip-devices and droplet-based microfluidics). We will involve four HQP, i.e., two Ph.D. students, an undergraduate student and a postdoctoral researcher, to perform interdisciplinary research spanning magnetics, mechanics, soft materials, nanoscience, and transport phenomena using mathematical modeling, experiments and numerical simulations.

今天创建的对象主要是被动的，即，它们在制造后不能改变其形式或功能。一种超越这种严重限制的新方法是制造嵌入功能性人工制品的3D对象，这些人工制品可以响应外部刺激而改变属性。磁性纳米粒子之间的静磁相互作用将被用于以比现有的自组装方法更简单和更灵活的方式产生可逆的自组装结构。从相同的初始磁性纳米颗粒分散体开始，外部施加的磁场的变化将提供宽范围的几何形状，这些几何形状将在复合材料周围的液体预聚物固化后被捕获在复合材料内。不同的自组装微结构的几何形状和它们的长程组织将使这些磁性纳米复合材料的可调体性能的设计和制造成为可能，例如它们的弹性模量、磁化率和剩磁以及电导率和热导率。这些性质将与特定的微结构组件相关，即，过程控制变量。这种变革性的方法将使材料的设计和制造具有先验规定的一组所需属性。理论、实验和数值模拟都将为这项研究提供信息。本研究将发展控制变数与自组装结构几何特性相关的标度法则，并透过实验加以验证。光学显微镜将用于二维微尺度成像，X射线计算机断层扫描用于三维微尺度成像，透射电子显微镜用于纳米尺度成像。数值模拟将使用布朗动力学提供拉格朗日跟踪的个别粒子耦合磁化动力学使用朗道-Lifshitz-吉尔伯特方程，以扩大调查超出实验限制。微观结构对机械性能的影响，如弹性模量将使用原子力显微镜的力体积模式和纳米压痕记录微尺度的不均匀性，和拉伸测试，以确定其对体弹性模量和各向异性的影响。剩磁的预测将验证磁力显微镜和自旋极化电子显微镜。将使用振动样品磁力测定法确定体磁特性。这项研究将使设计的微观结构的几何形状，以产生特定的散装材料的性能。它承诺跨越多个学科的转型应用，例如，医学（组织工程和细胞内致动器中的支架方法）、设备制造（MEMS和自旋电子设备）以及具有可调粗糙度的智能表面（用于芯片实验室设备和基于液滴的微流体）。我们将涉及四名HQP，即，两个博士学生，本科生和博士后研究员，进行跨学科的研究跨越磁学，力学，软材料，纳米科学和运输现象，使用数学建模，实验和数值模拟。