Focusing, aligning of particles in flow, serves as a prerequisite step for the downstream detection, separation, and manipulation. Especially, hydrophoretic focusing features easy operation and no need for external actuation since it uses the microstructure-induced pressure to arrange particles to the equilibrium positions, thus holding its potential in microfluidics. Now, we have developed a microchip with the V-shaped pattern by femtosecond laser (fs-laser) processing. When microparticles flow over the pattern, they tend to be focused to the centerline of the microchannel due to the hydrophoretic force induced by the interaction between the fluid and pattern (Fig. 1). In this work, we fabricated a microfluidic device by fs-laser processing and explored fluid dynamics at the pattern in the chip channel.

© 2019 Japan Society of Applied Physics, The Optical Society (OSA)

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