Enhancing Range of Transport in Optical Tweezers Assisted Microfluidic Chambers Using Automated Stage Motion

In this paper, we present a planning approach for automated high-speed transport of cells over large distances inside an Optical Tweezers (OT) assisted microfluidic chamber. The transport is performed in three steps that combine the optical trap and motorized stage motions. This includes optical trapping and transporting the cells to form a desired cell-ensemble that is suitable for a long distance transport, automatically moving the motorized stage to transport the cell-ensemble over a large distance while avoiding static obstacles, and distributing the cells from the ensemble to the desired locations using OT. The speeds of optical traps and the motorized stage are determined by modeling the motion of the particle under the influence of optical trap. The desired cell-ensemble is automatically determined based on the geometry of the microfluidic chamber. We have developed a greedy heuristic method for optimal selection of the initial and the final location of the cell-ensemble to minimize the overall transport time while satisfying the constraints of the OT workspace. We have discussed the computational complexity of the developed method and compared it with exhaustive combinatorial search. The approach is particularly useful in applications where cells are needed to be rapidly distributed inside a microfluidic chamber. We show the capability of our planning approach using physical experiments.