A high‐discernment microflow cytometer with microweir structure

Abstract

Using a simple and reliable isotropic wet etching process, we fabricated a microflow cytometer in which cells/particles are concentrated in the center of the sample stream using a 2-D hydrodynamic focusing technique and an microweir structure. Having focused the cells/particles, they are detected and counted using a LIF method. The experimental and numerical results confirm the effectiveness of the hydrodynamic sheath flows in squeezing the cells/particles into a narrow stream in the horizontal X-Y plane. Furthermore, it is shown numerically that the microweir structure results in the separation of the cells/particles in the vertical X-Z plane such that they pass through the detection region in a sequential fashion and can therefore be counted with a high degree of precision. The experimental results obtained using fluorescent polystyrene beads with diameters of 5 and 10 microm, respectively, confirm the suitability of the proposed device for microfluidic applications requiring the high-precision counting of particles or cells within a sample flow.

Miniaturized flow cytometer with 3D hydrodynamic particle focusing and integrated optical elements applying silicon photodiodes

“…Flow cytometry based on optical inspection techniques (Shapiro 2003) has been successfully used for many years due to its distinct advantages in terms of detection sensitivity, versatility, and excellent reliability (Huh et al 2005;Ateya et al 2008;Zhang et al 2009). It offers a wide variety of detection platforms [e.g., fluorescence illumination: Tung et al (2004), Bernini et al (2006), Malic and Kirk (2007), Wu et al (2008), Fu et al (2008); extinction: Fu et al (2004), Kummrow et al (2009); and scattering measurements: Wang et al (2004), Golden et al (2009), Chen and Wang (2009)] to inspect relevant sample parameters. A suspension of particles or cells is introduced into a configurable fluidic system where they are hydrodynamically focused to significantly increase the detection sensitivity.…”

A Magnetic Micropump Based on Ferrofluidic Actuation

“…These devices have emerged as a powerful toolset for miniaturization, reducing power consumption, reducing sample and reagent use, improving sensitivity, improving efficiency, reducing processing times, increasing portability, and allowing for integration with other miniaturized devices. Several functional microfluidic devices have been developed to perform a variety of tasks, including sample pre-treatment and injection, micropumps, micromixers, micro distillation, polymerase chain reactions (PCR), and cell/particle separation and counting [6][7][8][9][10][11][12][13][14][15].…”

A hydrodynamic focusing microchannel based on micro-weir shear lift force

“…[15][16][17][18][19][20] In a typical microflow cytometer, the cells/particles are injected into an electrolyte solution and are then focused in the horizontal plane by two sheath flows such that they pass through the detection region of the device in a single line fashion. 21,22 Fu et al 23 developed an electrokinetically driven microflow cytometer in which the sample was focused in the horizontal a) Author to whom correspondence should be addressed. Electronic mail: loudyfu@mail.npust.edu.tw.…”