A Novel Micropipette Robot for Cell Manipulation Based on Dielectrophoresis and Electroosmotic Vortex

Abstract

In the past few decades, various methods have been considered and utilized to demonstrate cell manipulation which is an essential demand in biological research. Some methods using electric field attract a lot of attention as they are label-free and can perform in the aqueous environment. In this paper, we present a micropipette robot for cell manipulation that a low-frequency and low-voltage electric field is applied on micropipette to generate dielectrophoretic effect and electroosmotic vortex around a micropipette tip. The position of the cell relative to the tip opening varies the net force acting on the cell which is high directivity. We demonstrated the successful cell manipulation by the micropipette robot, including trapping, transportation, releasing and patterning. During the manipulation process, the deformation of cell affects the amplitude of the micropipette resistance. By monitoring the micropipette resistance, a high precision cell manipulation method has been proposed and validated with arraying HEK 293 cells. The micropipette robot simplifies the cell manipulation that an electric field (constant square wave) can attract and repel cells at the same time, and the system also monitors the manipulation process accurately. Our study provides a further perspective for cell manipulation that the coexistence of electrodynamics and hydrodynamics can be combined to design and develop easy-to-implement manipulator at nano/micro scale.