Swarm-inspired transportation of biological cells using saturation-controlled optical tweezers

Transportation manipulation of biological cells, where cells are required to move into a fixed or moving region, has recently attracted increasing attention in bioscience and nanomedicine. Currently, the multicell transportation in practical applications is implemented manually, with low precision and efficiency. This paper presents a swarm-inspired approach to automated transportation of multiple cells using robotically controlled optical tweezers. A swarming controller, where holographic optical tweezers function as end-effectors to manipulate the cells, was developed. To ensure that the cells do not escape from the optical traps, the controller was designed by incorporating a saturation control of the cell offset to the laser center. Because the optical tweezers can only be position-controlled, oscillation may easily occur. This problem was solved by integrating artificial first-order kinematics of the optical tweezers into the controller design. Experiments of transporting multiple yeast cells were performed to verify the effectiveness of the proposed approach.