Modeling and analyzing nano-particle pushing with an AFM by using nano-hand strategy

One of the major limitations for Atomic Force Microscopy (AFM) based nanoparticle pushing is that AFM only has one sharp tip as the end-effector. The interaction force between the nanoparticle and the tip is applied through a single point, which often leads the AFM tip to slip-away from the nanoparticle due to their small touch area. Then several minutes is needed to relocate the missed nanoparticle by a new image scan. Moreover, if the nanoparticle is very soft, the sharp tip may damage the particle instead of pushing it away due to the cutting effect of the sharp tip. In this paper, a nano-hand strategy is proposed to resolve this problem. Based on the theoretical analysis to the behavior model of nanoparticle, the pushing points, pushing step-length and pushing speed of AFM tip are planned artfully, through which a multi-tip manipulation effect can be imitated with a single tip. The nanoparticle is pushed as by a virtual nano-hand during manipulation,. In this way, the slip-away problem due to single AFM tip pushing can be get rid of efficiently. The simulation and experiments results show the increased effectiveness of AFM based nanomanipulation.