(222j) Study of Cell Viability after Manipulation with Insulator-Based Dielectrophoresis

Food and water safety, environmental monitoring and clinical screening are examples of fields where microfluidic devices or lab-on-a-chip systems can make a significant impact, since in these areas obtaining a rapid response is critical, particularly in analyses involving biological cells. Microfluidics has revolutionized the manner in which many assessments/processes are carried out. Biotechnology is one of the fields that has been most benefited with the marriage of microfluidics and analytical sciences. Many biotechnological applications require fast response methods that are able to handle/analyze high value biological products, such as cells, in a gentle manner, without leading to cell damage.

Insulator based dielectrophoresis (iDEP) is a leading microfluidics technique employed for the concentration, sorting and separation of samples containing cells.  In this technique cells are manipulated inside microchannels by utilizing non-uniform electric fields. Briefly, microchannels for iDEP contain an array of 3-dimensional insulating structures, electric field are across the microchannel by employing electrodes located at the channel inlet and outlet. The presence of the insulating structures creates a non-uniform electric field enabling dielectrophoresis. Many successful studies have been published on the analysis of cell using iDEP. However, during iDEP manipulation cells are exposed to high electric field gradients and Joule heating, which affects cell viability. The present study will quantify the decrease of cell viability after exposure to iDEP manipulation.  Both E.coli and Yeast were tested in identical iDEP microdevices only varying in post geometries. Six different post geometries were analyzed, three cylindrical and three diamond, at three different time durations.