High-Efficiency Small Sample Microparticle Fractionation on a Femtosecond Laser-Machined Microfluidic Disc

Abstract

The fabrication and testing of microfluidic spinning compact discs with embedded trapezoidal microchambers for the purpose of inertial microparticle focusing is reported in this article. Microparticle focusing channels require small features that cannot be easily fabricated in acrylic sheets and are complicated to realize in glass by traditional lithography techniques; therefore, the fabrication of microfluidic discs with femtosecond laser ablation is reported for the first time in this paper. It could be demonstrated that high-efficiency inertial focusing of 5 and 10 µm particles is achieved in a channel with trapezoidal microchambers regardless of the direction of disc rotation, which correlates to the dominance of inertial forces over Coriolis forces. To achieve the highest throughput possible, the suspension concentration was increased from 0.001% (w/v) to 0.005% (w/v). The focusing efficiency was 98.7% for the 10 µm particles and 93.75% for the 5 µm particles.

Editorial for the Special Issue on Inertial Microfluidics

“…The remainder of this Special Issue includes original research articles on technical innovations of inertial microfluidics for various applications [ 5 , 6 , 7 , 8 ]. Kim et al [ 5 ] report the separation of two freshwater, commercially important, microalgal species, namely, Chlorella Vulgaris and Hematococcus Pluvialis.…”

“…Notably, the horizontal elliptic arrangement of the spinal channel outperformed its vertically arranged counterpart when the identical channel geometry and ellipse aspect ratio were implemented. The report by Al-Halhouli et al [ 8 ] describes the fabrication method and particle concentration performance of the trapezoidal microchambers on a spinning compact disk made out of an inert glass wafer. A femtosecond laser machining was tested as a simpler, alternative fabrication method to soft lithography.…”