Method to study the single cell's time-variation adhesion strength during the manipulation inside ESEM

The cell adhesion force to the substrate is important for the cell manipulation. In our previous work, the maximum cell adhesion force during the manipulation has been studied. However, the relation ship of the force virus time was still not clear. In this paper, a method to measure the time-variation adhesion force during the manipulation was proposed. A hybrid laser sensor and nanorobotic manipulation system was build inside an environment scanning electron microscope (ESEM). A micro putter was fabricated from an atomic force microscope (AFM) cantilever through focused ion beam (FIB) etching technique. The laser head and the micro putter were assembled and fixed to the nano manipulator inside ESEM chamber. The displacement between the micro putter and the laser head can be measured by the laser sensor system. The relationship of the deflection of the micro putter and the applied force was calibrated by nanorobotic manipulation approach. The single cell's time-variation adhesion force to substrate surface was measured based on this hybrid system. The result indicates that both the dynamic data and precise observation can be achieved owing to the combination of the advantages of AFM and ESEM nano robotic manipulation system.