EAGER: Microfluidic platform for regulating transport in particle suspensions using synthetic cilia

1256403PI：Alexev本项目的目标是开发一个微流体平台，用于研究具有仿生合成纤毛覆盖的微通道中颗粒悬浮的动态行为。计算机模拟预测，合成纤毛可以产生循环二次流，既可以将微观颗粒引导到纤毛壁，也可以在流体力学中排斥它们，这种纤毛作用是由它们相对于流动方向的倾斜来定义的。在另一种使纤毛对磁场产生响应的方法中，纤毛将首先溅射一层非常薄的钛，然后使用电镀或电子束蒸发在纤毛上涂覆镍。微流控试验室中的实验与直接数值模拟相结合，将被用来探索合成纤毛与流动流体的相互作用，并研究它们如何影响微米级颗粒的沉积。合成纤毛表面可用于各种涉及流体输送颗粒的应用。具体地说，纤毛表面可以用来选择性地吸引和捕获流体中的颗粒。这将使新的过滤和传感方法的开发成为可能，这些方法可以检测和分离特定的合成颗粒和生物细胞。合成纤毛排斥悬浮颗粒的能力可以被利用来创造新的自清洁和防污染表面。

1256403PI: AlexeevThe goal of this project is to develop a microfluidic platform for studying the dynamic behavior of particle suspensions in microchannels with walls covered by biomimetic synthetic cilia. The microfluidic platform will be used to test a hypothesis that synthetic ciliated surfaces can be utilized to regulate transport of microscopic particles suspended in a flowing fluid. Computer simulations predict that synthetic cilia can create circulatory secondary flows that can either direct microscopic particles towards the ciliated wall or hydrodynamically repel them, and this cilium action is defined by their tilt with respect to the flow direction. Responsive compliant cilia will be manufactured from poly(dimethyl)siloxane (PDMS) with addition of magnetically-sensitive nanoparticles using soft lithography technique. In an alternative approach to make cilia responsive to magnetic field, cilia will be first sputtered with a very thin layer of Ti and then they will be coated with Ni using electroplating or e-beam evaporation. Experiments will be conducted in microchannels with regular arrays of responsive cilia that can be bent by either an imposed fluid flow or an external magnetic field. A combination of experiments in the microfluidic test cell with direct numerical simulations will be used to probe the interactions of the synthetic cilia with flowing fluids and examine how they affect deposition of micrometer-sized particles. By creating synthetic, controllable cilia that can be incorporated into microfluidic devices, this project will establish a new approach for regulating motion of microparticles in microfluidic systems. Synthetic ciliated surfaces can be employed in a variety of applications that involve particle transport by fluid flow. In particular, ciliated surfaces could be used to selectively attract and trap particles from fluid. This will enable the development of novel filtration and sensory methods that could detect and isolate specific synthetic particles and biological cells. The ability of synthetic cilia to repel suspended particles could be harnessed in creating new self-cleaning and antifouling surfaces.