0
Technical Briefs

# A Microfluidic Manipulator for Enrichment and Alignment of Moving Cells and Particles

[+] Author and Article Information
Hsiu-hung Chen, Dayong Gao

Department of Mechanical Engineering, University of Washington, Seattle, WA 98195

Bingbing Sun, Kenny K. Tran, Hong Shen

Department of Chemical Engineering, University of Washington, Seattle, WA 98195

J Biomech Eng 131(7), 074505 (Jun 04, 2009) (4 pages) doi:10.1115/1.3127258 History: Received September 16, 2008; Revised February 20, 2009; Published June 04, 2009

## Abstract

Grooved structures have been widely studied in particle separation and fluid mixing in microfluidic channel systems. In this brief report, we demonstrate the use of patterning flows produced by two different sorts of grooved surfaces: single slanted groove series (for enrichment patterns) and V-shaped groove series (for focusing patterns), into a microfluidic device to continuously manipulate the flowing particles, including microbeads with $6 μm$, $10 μm$, and $20 μm$ in diameter and mouse dendritic cells of comparable sizes to the depth of the channel. The device with grooved channels was developed and fabricated by soft-lithographic techniques. The particle distributions after passing through the single slanted grooves illustrate the size-dependent enrichment profiles. On the other hand, particles passing through the V-shaped grooves show focusing patterns downstream, for the combination effect from both sides of single slanted grooves setup side-by-side. Compared with devices utilizing sheath flows, the focusing patterns generated in this report are unique without introducing additional flow control. The alignment of the concentrated particles is expected to facilitate the visualization of sizing and counting in cell-based devices. On the other hand, the size-dependent patterns of particle distributions have the potential for the application of size-based separation.

<>

## Figures

Figure 1

Schematic of grooved channels with suspended particles. (a) Evenly distributed particles are introduced to the area with a set of rectangular grooves on the bottom of the channel. The coordinate system (x,y,z) and (x′,y′,z) defines the principle axes of the channel and the grooves, respectively. Flow direction is parallel to x-axis. The average flow profile in the y-z cross section without the grooves is drawn schematically at the top-right corner. The streamlines of the transverse flow in the y-z cross section without the grooves is shown at the bottom-left corner. (b) The particles are continuously biased toward the positive y-axis. The angle α defines the orientation of the grooves with respect to the channel. The depth and width of the grooves are h and +, respectively. The diameter d of the particles is smaller but comparable to the depth of the channel, H. (Reprinted from Chen and Gao (34), with permission)

Figure 2

Experimental data for 6 μm, 10 μm, and 20 μm particles (data from (34)) and mouse dendritic cells. (a) Snapshot of mDCs at the observation area downstream display a clear pattern of the enrichment to the right. (b) Distribution line associated with 6 μm, 10 μm, and 20 μm particles and mDCs show size-dependent distribution profiles after passing through the microfluidic channels with single slanted grooves. The scale bar represents 50 μm.

Figure 3

Experimental results associated with V-shaped grooves. (a), (b), and (c) are snapshots for the cases of 6 μm, 10 μm, and 20 μm particles, respectively, at the observation area downstream. Arrows indicate the flow direction. (d) Distribution profiles for 6 μm, 10 μm, and 20 μm particles show clear focusing patterns after passing through the microfluidic channels with V-shaped grooves. The scale bar represents 50 μm in (a), (b), and (c).

## Discussions

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections