Robot-aided optical manipulation of cells with a unified controller

In cell manipulation with optical tweezers, it is required that the cell must be located within the optical trap. Due to the lack of a control technique that can automatically locate the cell within the optical trap while controlling the cell motion, the cell will easily escape from the optical trap and hence the manipulation task is failed. Therefore, development of a unified controller that can control both cell trapping and cell motion simultaneously has received increased attention in optical cell manipulations. In this paper, we addressed this challenging problem by developing a novel visual based control method that controls both cell positioning and cell trapping simultaneously. We first established a new geometric model aiming for confining the cell within a local region near the optical trap, and then formulated a so-called Cell-Tweezers Coalition (C-T Coalition). We secondly developed a potential field function based controller to drive the C-T Coalition to the desired position while avoiding collisions with any other obstacles in environment. Finally, we performed experiments of transferring yeast cells to demonstrate the effectiveness of the proposed approach.