Control of an atomic force microscopy probe during nano-manipulation via the sliding mode method

Nowadays, designing a reliable controller for an Atomic Force Microscope (AFM) during the manipulation process is a main issue, since the tip can jump over the target nanoparticle and, thus, the process can fail. This study aims to design a Sliding Mode Controller (SMC) as a robust chattering-free controller to push nano-particles on the substrate. The first control purpose is positioning the micro cantilever tip at a desired trajectory by the control input force, which can be exerted on the micro cantilever in the YY direction by an actuator located at its base. The second control target is the micro-positioning stage in XX, YY directions. The simulation results indicate that not only are the proposed controllers robust to external disturbances and nonlinearities, such as deflection of the AFM tip, but are chattering free SMC laws that are able to make the desired variable state to track a specified trajectory during a nano-scale manipulation.