Effects of light size and intensity on photoconductive effect-based
optically-induced dielectrophoresis for three-dimensional manipulation
Abstract
In this paper, the effect of light size and intensity on photoconductive
effect-based optically-induced dielectrophoresis (ODEP) for
three-dimensional manipulation of cells is studied. The photoconductive
effect-based ODEP enabled the three-dimensional manipulation of multiple
cells, whether normal cells or cancer cells. When the light spot size is
similar to the cell and the photoconductive layer resistance is about
150 MΩ, the spot repels other cells after manipulating a single cell.
When the light spot size is much larger than the cell and the
photoconductive layer resistance is about 120 MΩ, multiple cells are
controlled inside the spot and distributes in the same plane. When the
light intensity is increased and the photoconductive layer resistance is
about 40 MΩ, the cells are manipulated in three-dimensions. Using a
light spot similar in size to the cells to gather specific cells at
different locations into a specific area, and then increasing the light
intensity enabled three-dimensional manipulation. We find that the cells
three-dimensional manipulation by ODEP is achieved only when the
photoconductive effect induced by the light pattern reaches a higher
intensity. The realization of ODEP-based three-dimensional manipulation
is related to the spot size and the photoconductive layer resistance
determined by light intensity.