Contributors: J. Taylor, C. L. Ren, G. D. Stubley
The development of Lab-on-a-Chip devices calls for the isolation or separation of specific bio-particles or cells. The design of a miniaturized sorting device for handheld operation must follow the strict parameters associated with Lab-on-a-Chip technology. The limitations include applied voltage, high efficiency of cell-separation, reliability, size, flow control, and cost, among others. Currently used designs have achieved certain levels of success, however, integration of multiple functions onto one single chip has not been fully realized yet. Several ongoing projects are planned in this direction. One example is illustrated below.
This study numerically and experimentally evaluates specific design modifications that contribute to:
i) The reduction of required applied potential aiming for developing portable devices using asymmetry channel width for focusing and injecting channels, respectively.
Asymmetry channel focusing.
Under the same applied potentials, a higher focusing channel width provides stronger focusing.
ii) Improved operation reliability by minimizing induced pressure disturbance when electrokinetic pumping is employed. Shallow channels are used as high flow resistance elements throughout the flow network to suppress induced pressure disturbance.
Fabricated polydimethylsiloxane (PDMS) chip.
With high flow resistance elements.
Without high flow resistance elements.
iii) Directing streams to assist particle flow control.
Dynamic flow switching using a directing stream.
Bibliography
J. Taylor, G.D. Stubley, C. L. Ren, “Experimental Determination of Sample Stream Focusing with Fluorescent Dye (PDF)”, Electrophoresis, 29 (2008) 2953-2959.
30) J. Taylor, C. L. Ren, G.D. Stubley, “Numerical and Experimental Evaluation of Microfluidic Sorting Devices (PDF)”, Biotechnology Progress, 24 (2008) 981-991.