The Influence of Electric Parameters on the Manipulation of Biological Cells in a Microfluidic System Using Optically Induced Dielectrophoresis

The integration of optically induced dielectrophoresis (ODEP)-based cell manipulation in a microfluidic system has been actively proposed for various biomedical researches. To realize ODEP-based cell manipulation for a special application, the selection of an appropriate ODEP operating condition is critical. The magnitude and frequency of the exerted electric voltage in an ODEP system are the two commonly-used working parameters. Although several studies had explored the influence of electric conditions on the cell manipulation using ODEP, few of them further considers the other co-existing phenomena which might affect the intended application of ODEP-based cell manipulation. To address this issue, this study has investigated the influence of electric parameters [i.e., magnitude and frequency of electric voltage: 1-10 Vpp and 1 kHz - 10MHz, respectively] on the ODEP-based cell manipulation. Results revealed that cell lysis could occur under low electric frequency (e.g., 1 kHz). Moreover, most of the cells were not effectively manipulated when the electric frequency was lower than 100 kHz due to cell adhesion on substrate surface. Conversely, most of the cells were effectively manipulated when the electric frequency reached 200-300 kHz. However, these manipulated cells tended to aggregate. This phenomenon could be prevented when the electric frequency was higher than 1 MHz. At a given electric frequency of 1 MHz, furthermore, the magnitude increase of electric voltage (2-8 Vpp) did not cause the unwanted phenomena aforementioned but increase the maximum velocity of a dynamic light image that can manipulate cells. At a given magnitude of electric voltage, conversely, further increase (higher than 1 MHz) of electric frequency might compromise the maximum velocity of a dynamic light image that can manipulate cells. Overall, all these information is important for scientists to select appropriate electric parameters for the cell manipulation using ODEP.