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

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

1256403 PI: Alexeev The 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.