DMREF: Collaborative Research: Design of active ink for 3D printing: integrating modeling and experiments

该奖项支持一个由四名研究人员组成的多学科团队，使用建模，分析，计算机模拟和实验来研究使用活性颗粒悬浮液来增强3D打印应用中油墨的性能。 以合成自推进粒子悬浮液为代表的活性材料从其环境中获取能量并改变周围流体的性质。 它们具有新颖的材料性能和广阔的应用前景。 在这里，介绍了一种用于3D打印的油墨的新概念，称为“活性油墨”。 即使是流体中的一小部分活性自推进颗粒也会导致粘度急剧降低，从而增强通过喷嘴的油墨输送并提高打印速度。 该项目将促进新材料的设计和制造，大大缩短从原型到产品的路径。 这项研究还将为学生和博士后提供高度多学科的培训和教育，他们将学习应用数学和计算的理论技术，以及化学和纳米纤维中采用的实验技术。 除了开发新的3D打印技术外，这项工作还将导致新的数学模型和有效的计算算法。由于合成自推进颗粒的存在，活性油墨的有效粘度将大幅降低，自扩散率将增加。 有效粘度的降低将增强油墨通过喷嘴的输送。 有效自扩散率的增加将使得能够更快地聚合，从而导致分辨率增强和更准确的3D特征设计。 此外，由于它们对所施加的剪切流的根本不同的响应，活性颗粒的使用可能导致具有新颖的颗粒分布的复合材料的设计。 活性颗粒的官能化还将允许调节硬化聚合物的性质。 新的数学模型将开发和分析数字和分析。 他们的预测将得到实验验证。 基于动力学理论的连续介质偏微分方程模型将进行渐近和数值分析。 这里的一个关键挑战是通过采用不动点和拓扑度理论的方法来找到定常流解。 在基于粒子的模型的模拟中，挑战在于准确地捕捉活动棒移动时发生的反应的动态。 连续介质模型模拟的一个困难是将分子尺度的反应纳入到中尺度的方法中。 通过解决这些挑战，这些计算方法的实用性和适用性将得到显着扩展，使它们能够用于模拟广泛的多组件，动态系统。

This award supports a multidisciplinary team of four investigators using modeling, analysis, computer simulations, and experiments to study using suspensions of active particles to enhance the properties of inks for applications in 3D printing. Active materials represented by suspensions of synthetic self-propelled particles harvest energy from their environment and alter the properties of the surrounding fluid. They have novel materials properties and promising applications. Here, a new concept of ink for 3D printing, termed "active ink", is introduced. Even a small fraction of active self-propelled particles in a fluid results in a dramatic reduction of viscosity, enhancing ink transport through the nozzle and increasing printing speed. This project will facilitate the design and manufacture of new materials, significantly shortening the path from prototype to product. This research will also enable a highly multidisciplinary training and education of students and postdocs who will learn theoretical techniques in applied mathematics and computations, as well as experimental techniques employed in chemistry and nanofabrication. Apart from the development of new 3D printing technology, the work will lead to novel mathematical models and efficient computational algorithms.A drastic reduction of effective viscosity and increase of self-diffusivity of the active ink due to the presence of synthetic self-propelled particles will be studied. The reduction of the effective viscosity will enhance ink transport through the nozzle. The increase of the effective self-diffusivity will enable faster polymerization resulting in resolution enhancement and more accurate 3D feature design. In addition, due to their fundamentally different response to applied shear flow, the use of active particles may lead to the design of composite materials with novel distributions of particles. The functionalization of active particles also will allow tuning the properties of the hardened polymer. New mathematical models will be developed and analyzed both numerically and analytically. Their predictions will be experimentally verified. The continuum partial differential equation model based on kinetic theory will be analyzed asymptotically and numerically. A key challenge here is to find stationary flow solutions by employing methods from fixed-point and topological degree theory. In simulations of particle-based models, the challenge is to accurately capture the dynamics of the reaction that occurs as the active rods move. A difficulty in simulations of the continuum model is incorporating the molecular-scale reactions into a mesoscale approach. By addressing these challenges, the utility and applicability of these computational methods will be significantly expanded, allowing them to be used for simulating a broad range of multi-component, dynamical systems.