A novel miniature dynamic microfluidic cell culture platform using electro-osmosis diode pumping.
An electro-osmosis (EOS) diode pumping platform capable of culturing cells in fluidic cellular micro-environments particularly at low volume flow rates has been developed. Diode pumps have been shown to be a viable alternative to mechanically driven pumps. Typically electrokinetic micro-pumps were limited to low-concentration solutions (≤10 mM). In our approach, surface mount diodes were embedded along the sidewalls of a microchannel to rectify externally applied alternating current into pulsed direct current power across the diodes in order to generate EOS flows. This approach has for the first time generated flows at ultra-low flow rates (from 2.0 nl/s to 12.3 nl/s) in aqueous solutions with concentrations greater than 100 mM. The range of flow was generated by changing the electric field strength applied to the diodes from 0.5 Vpp/cm to 10 Vpp/cm. Embedding an additional diode on the upper surface of the enclosed microchannel increased flow rates further. We characterized the diode pump-driven fluidics in terms of intensities and frequencies of electric inputs, pH values of solutions, and solution types. As part of this study, we found that the growth of A549 human lung cancer cells was positively affected in the microfluidic diode pumping system. Though the chemical reaction compromised the fluidic control overtime, the system could be maintained fully functional over a long time if the solution was changed every hour. In conclusion, the advantage of miniature size and ability to accurately control fluids at ultra-low volume flow rates can make this diode pumping system attractive to lab-on-a-chip applications and biomedical engineering in vitro studies.
Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University , Houghton Michigan 49931, USA.
Jen-Yung
JY
Chang
Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University , Houghton Michigan 49931, USA.
Shuo
S
Wang
Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University , Houghton Michigan 49931, USA.
Jeffrey S
JS
Allen
School of Mechanical Engineering, Chung-Ang University , 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756, South Korea.
Seong Hyuk
SH
Lee
School of Chemical Engineering and Materials Science, Chung-Ang University , 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756, South Korea.
Suk Tai
ST
Chang
School of Mechanical Engineering, Chung-Ang University , 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756, South Korea.
Young-Ki
YK
Choi
Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University , Houghton Michigan 49931, USA.
Craig
C
Friedrich
Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University , Houghton Michigan 49931, USA.
Chang Kyoung
CK
Choi