Exploration of the Feasibility of Using Electroosmotic Pumps in Cell Culture

A new continuous perfusion cell culture chip is studied that utilizes electroosmotic pumping to control fluid flow. Electroosmotic flow is not typically used for living cells due to the inherently high electric fields that may harm cells. Problems associated with EOF and cells are solved by incorporating electroosmotic pumps (EO pumps) which generate an induced pressure driven flow in regions with cells. Several advantages of EO pumps include pulse free flow, quick flow control and precise movement of minute volumes of fluid. An ion exchange system consisting of photopolymerized salt bridges are used to separate the media from the electrode reservoirs. However, the high salt concentration in cell culture medium creates significant problems for EO pumps such as decreased flow rate due to low zeta potential, increased electrolysis due to high current draw, significant joule heating, bubble formation and polarization. Attempts to solve these problems with the proposed microfluidic chip are discussed. The pumps are characterized to determine the flow rate for applied currents. Preliminary results with rainbow trout gill cells show that pump can be operated for 5hrs without harming the cells. The work presented here discusses the design and development of the system to this point.