SEM Image-Based 3-D Nanomanipulation Information Extraction and Closed-Loop Probe Control

To achieve a scanning electron microscope (SEM) and virtual reality-based nanomanipulation system, this paper addresses 3-D nanomanipulation information extraction based on 2-D SEM images, after briefly explaining how to establish the 3-D virtual environment. An image border repair algorithm based on an eight-neighboring method is proposed to obtain the accurate 2-D coordinates of the probe and nanowire even when they are in contact. To determine the coordinates of the Z probe, a method based on the grayscale standard deviation of 2-D SEM images is proposed. Through these converted coordinates, the model can be updated and controlled in a virtual environment. Finally, a fuzzy proportional-integral-derivative (PID) controller is designed to control the actual probe position and to improve the system accuracy. Simulations and experimental results demonstrate that the system exhibits good output characteristics in either dynamic-state or steady-state, when controlled with the fuzzy PID.