Experimental study of the interaction of near-wall flow with flexible polymers at micro-scale

该项目是亚琛工业大学空气动力学研究所与海德堡大学Spatz教授和萨尔布尔<s:1>肯大学Zimmermann教授组成的研究小组合作的一部分。实验研究的目的是详细分析在确定的剪切流中，聚合物锚定在柔性微柱顶部的近壁流动与聚合物的相互作用。微合成弹性柱用于将大分子定位在规定的壁距内，并通过柱的弯曲来测量聚合物的变形力。利用微尺度粒子成像测速和延时显微镜技术，详细研究了微柱和锚定聚合物与流动的相互作用。实验研究可以详细分析流场是如何使聚合物变形的，以及聚合物的存在是如何改变流场的，这两个问题都是由合作伙伴之一的Zimmermann教授从理论上研究的。此外，流场的详细知识对于理解剪切诱导的运输和生化反应是很重要的，Spatz教授的团队用类似的装置进行了研究。他们使用微柱表面作为力测量装置，用于研究生物分子网络上的生化反应。

The proposed project is part of a cooperation of the Institute of Aerodynamics, RWTH Aachen with the research group of Prof. Spatz, Univ. Heidelberg and Prof. Zimmermann, Univ. Saarbrücken. The aim of the experimental study is the detailed analysis of the interaction of near-wall flow with polymers anchored on top of flexible micropillars in a defined shear flow. The micro-fabricated elastomeric pillars are used to position the macromolecules in a defined wall distance and to measure the deformation forces of the polymers via the pillar bending. The interaction of the micro-pillars and the anchored polymers with the flow is studied in detail using Particle-Image Velocimetry measurements at microscale (micro-PIV) and timelapse microscopy. The experimental study allows a detailed analysis how the flow field deforms the tethered polymers and how the flow field is modified by the presence of the polymers, both issues of which are theoretically studied by Prof. Zimmermann, one of the cooperating partners. In addition, the detailed knowledge of the flow field is important to understand shear induced transport and biochemical reactions investigated with a similar device by the group of Prof. Spatz. They use the micropillar surface as a force measurement device for the study of biochemical reactions on networks of biomolecules.