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

1256403 PI：Alexeev本项目的目标是开发一个微流控平台，用于研究颗粒悬浮液在微通道中的动态行为，微通道的壁被仿生合成纤毛覆盖。微流体平台将用于测试一个假设，即合成纤毛表面可以用来调节悬浮在流动流体中的微观颗粒的运输。计算机模拟预测，合成纤毛可以创建循环的二次流，可以直接微观粒子对纤毛壁或流体动力学排斥他们，这种纤毛行动是由他们的倾斜相对于流动方向定义。响应性顺应纤毛将使用软光刻技术由聚（二甲基）硅氧烷（PDMS）添加磁敏感纳米颗粒制造。在使纤毛响应于磁场的替代方法中，纤毛将首先溅射有非常薄的Ti层，然后它们将使用电镀或电子束蒸发涂覆有Ni。实验将在微通道中进行，微通道具有规则的响应纤毛阵列，这些纤毛可以通过施加的流体流动或外部磁场弯曲。将微流体测试单元中的实验与直接数值模拟相结合，用于探测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。通过创建可以并入微流体设备的合成可控纤毛，该项目将建立一种用于调节微流体系统中微粒运动的新方法。合成纤毛表面可用于涉及通过流体流动的颗粒输送的各种应用中。特别地，纤毛表面可用于选择性地吸引和捕获来自流体的颗粒。这将有助于开发新的过滤和传感方法，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用来创造新的自清洁和自清洁表面。

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.