Apply robot-tweezers manipulation to cell stretching for biomechanical characterization

Robotic manipulation of living cells offers us an ability to study biological cells at single cell level, which has received increasing attention in recent years. Optical tweezers technology is such a powerful tool that can apply force and deformation on a cell with resolution at piconewton and nanometer, respectively. In this chapter, we present an approach to integrating optical tweezers into robotic manipulation for cell stretching, and further, for characterizing biomechanical properties of cells. To extract cell properties from the mechanical responses of cells, a theoretical model is developed to reveal cell deformation behaviors. By comparing simulation results to experimental data, the mechanical properties of cells can be characterized. Further, we apply this established modeling and characterization approach to human blood cells for biomechanics study. Our latest results indicate that the mechanical stiffness of human red blood cells increases with elevation in tonicity of suspended solutions, and myeloblasts from acute myeloid leukemia patients with different immunophenotypes exhibit distinct mechanical properties.