Fundamentals of Viscous Withdrawal, Flow-Focusing & Light-Driven Jetting

提案编号：CBET-0730629 主要研究员：ZHANG, WENDY W. 机构：芝加哥大学 粘​​性提取、流动聚焦和光驱动喷射的基础知识 新的工程流程可以准确、快速地操纵少量液体。这些技术使得纹理控制在微米到亚微米尺度的新材料成为可能。理论/数值分析将阐明整体流动和界面变形之间的相互作用。重点将放在三个示例问题上：粘性夹带、细胞封装和光诱导喷射。这三者都具有直接的技术相关性。可以控制粘性液体的夹带来产生薄而稳定的微米尺寸的喷嘴。这是纤维和线材制造中的关键步骤。细喷嘴还可以均匀地涂覆不规则形状的固体颗粒。特别是，它目前封装了产生胰岛素的胰岛，以努力开发 I 型糖尿病的移植疗法。光诱导喷射提供了一种完全利用激光束发出的光来生产和运输少量液体的方法，无需预制微通道。 PI 将在描述粘性流和表面变形之间相互作用的通用框架内分析这些问题。基于先前成功模拟会聚流产生的界面变形的工作，将有助于开发简单的渐近过程模型以及用于与实验进行定量比较的数值模型。更广泛的影响包括对动力学进行定量分析，以确定液体衬里管中气泡上升所达到的速度，这对于气道闭合医学治疗的发展以及当前微流体装置的发展发挥了重要作用。从该分析中获得的结果可能与电纺丝中复合纤维的形成、通过微流体通道中的流动聚焦制造液滴、胶囊和光子带隙材料有关。这项研究还将纳入几个不同层面的科学教育。模拟结果的分析，特别是模拟结果与实验测量之间的比较，将成为芝加哥大学物理系赞助的暑期本科生/高中生研究计划的一部分。这项研究提出的一些更广泛的问题，特别是基础流体动力学与生物医学工程和纳米技术中的技术挑战之间的联系，将在研究生和本科生流体动力学课程中进行探讨。

PROPOSAL NO.: CBET-0730629 PRINCIPAL INVESTIGATOR: ZHANG, WENDY W. INSTITUTION: UNIVERSITY OF CHICAGO FUNDAMENTALS OF VISCOUS WITHDRAWAL, FLOW-FOCUSING & LIGHT-DRIVEN JETTINGNew engineering processes can manipulate small amounts of liquid with accuracy and speed. Such techniques make possible new materials whose textures are controlled on micron to sub-micron scales. A theoretical/numerical analysis will elucidate the interaction between bulk flow and interface deformation. Focus will be on three example problems: viscous entrainment, cell encapsulation and light-induced jetting. All three have direct technological relevance. The entrainment of a viscous liquid can be manipulated to create thin, stable micron-sized spouts. This is a crucial step in the manufacture of fibers and wires. Thin spouts can also coat irregularly-shaped solid particles uniformly. In particular, it currently encapsulates insulin-producing Islets in an effort to develop a transplant therapy for type I diabetes. Light-induced jetting offers a way to produce and transport small amounts of liquid using entirely light from a laser beam, without the need of pre-fabricated microchannels. The PI will analyze these questions within a common framework characterizing the interaction between viscous flow and surface deformation. Building on prior work successfully modeling the interface deformation produced by a converging flow will help develop simple, asymptotic models for the processes and also numerical models for quantitative comparisons to experiments. Broader impacts include quantitative analyses on the dynamics to determine the speed attained by a rising bubble in a liquid-lined tube has been instrumental in the development of medical treatments for airway closure, and in current development of microfluidic devices. Results obtained from this analysis are likely to be relevant to formation of compound fibers in electrical spinning, the manufacture of droplets, capsules and photonic band gap materials via flow-focusing in microfluidic channels. This research will also be incorporated into science education on several different levels. The analysis of simulation results, in particular the comparison between the simulation results and the experimental measurements, will be part of the summer undergraduate/high-school student research program sponsored by the Physics department at the University of Chicago. Some of the broader issues raised by this research, in particular the connection between fundamental fluid dynamics and technological challenges in bio-medical engineering and nanotechnology, will be explored in the graduate and undergraduate courses on fluid dynamics.