Cilia are microscopic, hair‑like structures found on the surface of many cells in nature. In humans, they line the inner surfaces of the trachea and lungs, where their coordinated motion transports mucus out of the respiratory system. In microorganisms, cilia located on the outer surface generate fluid flow that enables the organism to swim.1
Inspired by these natural systems, researchers have developed artificial cilia to reproduce similar flow‑generation mechanisms for use in microfluidic devices. In our laboratory, we focus on magnetic artificial cilia, whose motion is driven by externally applied magnetic fields. Until recently, most artificial cilia have been designed with simple cylindrical geometries to pump fluid through microfluidic channels. However, the shape of a cilium strongly influences the flow patterns it produces, and therefore its pumping performance. This idea is supported by earlier work from B. Chaichypour et al.2, who demonstrated that the cross‑sectional shape of micropillars significantly affects microstreaming and mixing efficiency. In their study, circular micropillars produced more effective mixing than star‑shaped ones. This project will take inspiration on their work to optimize not mixing, but flow generation by magnetic artificial cilia.
The goal of this project is to better understand how the cross‑sectional shape of artificial cilia influences fluid flow generation. As a student working on this project, you will fabricate cilia arrays embedded within microfluidic channels, using cilia with different cross‑sectional shapes. You will then use a dedicated magnetic actuation system to drive the cilia and establish fluid pumping. This will allow you to systematically compare how different cilia shapes affect fluid velocity and flow patterns.
Figure 1. Description of experimental project, focusing on the effect of different cross-sectional shapes of cilia on flow generation.
References
1 Z. Cui, Y. Wang, S. Zhang, T. Wang, & J.M.J. den Toonder, Miniaturized metachronal magnetic artificial cilia, Proc. Natl. Acad. Sci. U.S.A. 120 (35) e2304519120
2 Chaichypour, B., Jegatheeswaran, S., Salari, A. et al. Microfluidic mixing by micropost-driven acoustic microstreaming: effects of micropost shape, actuation voltage, and fluid flow rate. Microfluid Nanofluid 29, 70 (2025).
