Actuated Surface Attached Post Systems for Microscale Fluid Dynamics

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

PI: Superfine, Richard Proposal Number: 1437751 Myriad biological propulsion and mixing systems operate efficiently even in highly viscous or viscoelastic fluids. In all of these cases, nature has developed a common solution: the cilium. The goal of the proposed study is exactly this: to investigate the role of cilia in propulsion and mixing of fluid flows at the microscale. Results of this work will be applicable to problems of interest in biological and technological contexts in microfluidic applications. Pumping and mixing are the most critical technological challenges in current microfluidics. Since the flows are in the very slow, turbulent fluid motion cannot be supported, and consequently fluid mixing is very slow. The proposed research will answer interesting questions in how mechanical cilia can transport viscoelastic fluids, which may have large impacts on the field of microfluidic/lab on a chip technologies. Biomimetic representations of cilia in the form of microscale surface attached post (ASAP) arrays will be employed to pump and mix Newtonian and viscoelastic (VE) fluids. These posts will be actuated to respond to the flow. Though modeling work has been done for viscous fluids, very little experimental or theoretical literature exists for microactuator driven pumping in non-Newtonian fluids. The questions to be answered through this research are what forces are required for pumping or mixing, what beat shape is most effective and how does the beat frequency affect pumping? These questions will be answered in relation to hypotheses and theoretical considerations, and will be related to the rheological properties of the viscoelastic fluid.