Two-dimensional fine particle positioning under an optical microscope using a piezoresistive cantilever as a manipulator

In this paper, a fine particle manipulation system using a piezoresistive microcantilever, which is normally utilized in Atomic Force Microscopy, as the manipulator and force sensor, and a top-view Optical Microscope (OM) as the vision sensor is proposed. Modeling and control of the interaction forces among the manipulator, particle and surface have been realized for moving particles with sizes less than 3 μm on a silicon substrate in 2D. The microcantilever behaves also as a force sensor which enables contact point detection, real-time force measurements, and surface alignment sensing. A 2D OM real-time image feedback constitutes the main user interface, where the operator uses mouse cursor and keyboard for defining the tasks for the cantilever motion controller. Preliminary particle manipulation experiments are demonstrated for 2.02 and 1 μm gold-coated latex particles, and it is shown that the system can be utilized in 2D micro particle assembling.