Robotic manipulation of human red blood cells with optical tweezers for cell property characterization

Cell manipulation has received considerable attentions in recent years. Most of cell manipulations are performed manually without guarantee of high precision and high throughput. This paper reports our latest research on integrating robotics technologies into optical tweezers system for manipulation and biomechanical characterization of human red blood cells (RBCs). We first demonstrate the effectiveness of the robot-tweezers system in manipulation of micro-beads, which is followed by stretching RBCs to different levels of deformations. The whole manipulation process is conducted with visual guidance and position feedback control, where the cell stretching direction is determined automatically through image analysis. The relationship between the stretching force and the induced deformation is obtained through force calibration and image processing. To characterize the mechanical properties of RBCs from the obtained experimental results, a mechanical model based cell property characterization strategy is introduced. Comparing the modeling results to the experimental data, the mechanical properties of human RBCs are characterized. In conclusion, this study demonstrates that the robotic manipulation technology with optical tweezers can be used to manipulate biological cells, and further, to characterize the biomechanical properties based on the cell mechanical model.