Study of microscale hydraulic jump phenomenon for hydrodynamic trap-and-release of microparticles

Abstract

Easy trap-and-release of microparticles is necessary to study biological cellular behavior. The hydraulic jump phenomenon inspired us to conceive a microfluidic device for the hydrodynamic trap-and-release of microparticles. A sudden height increase in a microfluidic channel leads to a dramatic decrease in flow velocity, allowing effective trapping of the microparticles by energy conversion. The trapped particles can be released by stronger inertial force based on simply increasing the flow velocity. We present a systematic, numerical study of trap-and-release of the microparticles using multiphase Navier-Stokes equations. Effect of geometry flow velocity, particle diameter, and adhesion force on trap-and-release was studied.

Figure 1

Hydrodynamic trap-and-release phenomenon from hydraulic jump in nature; (a) circular hydraulic jump and hydraulic jump in nature; (b) hydrodynamic trap-and-release in hydraulic jump cavity; and (c) streamline comparison between flow and particle.

Figure 2

Geometric effects and flow velocity on hydrodynamic trap-and-release; (a) the η_trap and the η_release as a function of H at D_p=0.5 at Re=10⁻³; (b) the η_trap and the η_release as a function of Re at H=5.0,L=6.5, and D_p=0.5.

Figure 3

Particle size for trapping and η_trap as a function of adhesion force; strong (500–900 N∕m²) and weak adhesion force (100–500 N∕m²).