Frequency-Dependent Effects of Pulsatile Flow on Particle Inertial Focusing and Separation in Sinusoidal...

Area of Science:

• Microfluidics
• Biotechnology
• Particle Manipulation

Background:

• Inertial microfluidics uses hydrodynamic forces for high-speed particle and cell processing.
• Research primarily focuses on steady flows, neglecting real-world pulsatile flow variations.
• Understanding flow pulsation effects is crucial for reliable microfluidic applications.

Purpose of the Study:

• To investigate the impact of flow pulsation on inertial focusing and separation in sinusoidal microchannels.
• To determine the critical frequency influencing microfluidic system performance.
• To analyze the effects of pulsation frequency and amplitude on particle behavior.

Main Methods:

• Hydraulic-electric analogy used to analyze system dynamics and determine critical frequency (∼9 Hz).
• Experimental investigation of microparticle inertial focusing under steady and pulsatile flows.
• Evaluation of pulsation amplitude and frequency effects on particle distribution and binary mixture separation.

Main Results:

• Particle focusing and separation remained stable above the critical frequency (∼9 Hz).
• Performance degraded at lower frequencies; 5 Hz pulsation reduced purity for 15 μm and 10 μm particles.
• Pulsation frequency was identified as a more critical parameter than pulsation amplitude.

Conclusions:

• Flow pulsation significantly affects inertial microfluidic performance, particularly below a critical frequency.
• Pulsation frequency is a key determinant of focusing and separation efficiency.
• Results provide critical insights for designing robust microfluidic devices operating under non-ideal flow conditions.