Research on controller of active probe of AFM for micro-manipulation

摘要

AFM(Atomic Force Microscopy)has been used in micro-manipulation system of MEMS(Micro-electro-mechanical System)and NEMS(Nano Engineered and Molecular Systems)structure assembly,and biology cell manipulation.Active probe of AFM is a kind of smart structure,and has unique characteristics than common probe.A typical system construction and key technologies of micro-manipulation system based on AFM have been analyzed in this paper.The design methods of controller have also been addressed.It has been presented that adopting active probe is a valid way of precise micro-manipulation.In order to decrease collision force of the tip,and to avoid destroying precise MEMS structure or biology body,the information of position and force should be considered simultaneously.On the basis of studying the existing methods of force/position hybrid control,we find that the method of periodic-output-feedback control based on infinite dimension system is a good way of inhabiting probe vibration and decreasing collision force of the tip.In this paper,the basic principle and key technology of this controller have been introduced,and the validity has been proved through micro-manipulation experiments.The results of this paper are beneficial to the design of common controller of automatic micro-manipulation system and other smart structures.