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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610811
• 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.

今天创造的物体主要是被动的，即它们在制造后无法改变其形式或功能。克服这一严重限制的一种新方法是制造嵌入功能工件的 3D 对象，这些工件可以响应外部刺激而改变属性。磁性纳米颗粒之间的静磁相互作用将用于以比现有自组装方法更简单、更灵活的方式产生可逆自组装结构。从相同的初始磁性纳米粒子分散体开始，外部施加的磁场的变化将提供广泛的几何形状，这些几何形状将在其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几何形状及其长程组织将使这些磁性纳米复合材料的可调谐整体特性的设计和制造成为可能，例如弹性模量、磁化率和剩磁以及电导率和导热率。这些属性将与特定的微观结构组件相关，即与过程控制变量相关。这种变革性方法将使材料的设计和制造能够具有预先规定的一组所需性能。理论、实验和数值模拟都将为这项研究提供信息。这项研究将开发将控制变量与自组装结构的几何特征相关联的比例定律，并通过实验对其进行验证。光学显微镜将用于二维微米级成像，X射线计算机断层扫描将用于三维微米级成像，透射电子显微镜将用于纳米级成像。数值模拟将使用布朗动力学提供单个粒子的拉格朗日跟踪，并结合使用朗道-利夫希茨-吉尔伯特方程的磁化动力学，将研究扩展到实验极限之外。将使用力体积模式下的原子力显微镜和纳米压痕来测量微观结构对弹性模量等机械性能的影响，以记录微观尺度的不均匀性，并通过拉伸试验来确定其对体积弹性模量和各向异性的影响。剩磁的预测将通过磁力显微镜和自旋极化电子显微镜进行验证。体磁特性将使用振动样品磁力测定法来确定。这项研究将使微观结构几何形状的设计成为可能，以产生特定的散装材料特性。它有望实现跨越多个学科的变革性应用，例如医学（组织工程和细胞内执行器中的支架方法）、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设备）。微流控）。我们将涉及四名 HQP，即两名博士。学生、本科生和博士后研究员，利用数学建模、实验和数值模拟进行磁学、力学、软材料、纳米科学和输运现象的跨学科研究。