Manipulation of colloidal particles in a microchannel using inertial microfluidics

• Main Author: Dhamiri Zulhusmi Thahir
• Other Authors: Yang Chun, Charles
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/78536
• Institution: Nanyang Technological University

The precise control and manipulation of small particles in the microscale using inertial flow has various applications such as in high-throughput separation and filtration of biological cells. In inertial microfluidics, fluid is flowed through microchannels at intermediate Reynolds number of (~1 to ~100) where both viscosity and inertia are finite. In an inertial flow, several hydrodynamic forces exist that acts on particles which causes them to migrate to the same final equilibrium states called inertial focusing. In this study, investigation of the factors affecting focusing behavior of particles were done and to ultimately achieve filtration. Parameters such as using straight versus a sinusoidal channel were experimented on to observe particle focusing behavior. Particle concentration was also tested to see its effects on focusing. It was found that a sinusoidal channel with low concentration was optimum for focusing. A range of Reynolds number was experimented on a trifurcation channel to see at which range separation occurs. Next, the experiment was scaled down to study the effect of increasing channel aspect ratio on particle focusing. Microchannels with aspect ratio of 12 was seen to display inertial focusing near its side walls. Another trifurcation channel was fabricated with the same aspect ratio and collected the data to be quantified against its Reynolds number to see which gives the best separation efficiency.