Vibration control of AFM tip for nano-manipulation using combined sliding mode techniques

Atomic force microscope (AFM) can be used as nano-robotics manipulation tool for nanoparticle positioning, pushing, indenting, cutting and etc. control the vibration behavior of AFM and make the microcantilever tip track specified trajectory is very crucial to appropriately manipulate particles in nanoscales. The novel combined sliding mode approach has been investigated in this paper to obtain robust nonlinear control scheme for nano-manipulation. First (classical) and second order (SOSM) sliding mode techniques have been developed and applied to nonlinear dynamical and uncertain model of AFM cantilever beam to track the desired trajectories. The simulation results show chattering in reaching phase of classical sliding mode and undesired trajectory twisting in sliding phase of SOSM. Hence, combined first and second order sliding mode is proposed to achieve robust chattering-free vibration control of AFM tip.