Analysis of micro-object operation based on the dynamics considering the adhesion under an SEM

Techniques of arranging micrometer-sized objects with high repeatability under a scanning electron microscope (SEM) are required to construct highly functional micro-devices. Since micro-objects tend to adhere to other objects mainly by electrostatic force, the adhesive force is often being considered in basic researches of micro-object manipulation. These techniques, however, still do not achieve the desired repeatability, since many of them are being used just for the empirical effectiveness. Some even include the process of trial-and-error. Thus, we analyze the micro-object operation theoretically by considering the adhesion and rolling-resistance factors in a dynamic system consisting of a sphere, needle-shaped tool, and substrate. Through this analysis, we show that it is possible to control the fracture of the contact interfaces of the system selectively by determining the tool-loading angle appropriately. Based on the analysis, we also propose a practical method for the pick and place operation of a micro-sphere under an SEM