NONLINEAR MATHEMATICAL MODELING OF VIBRATING MOTION OF NANOMECHANICAL CANTILEVER ACTIVE PROBE

Abstract

NONLINEAR VIBRATION RESPONSE OF NANOMECHANICAL CANTILEVER (NMC) ACTIVE PROBES IN ATOMIC FORCE MICROSCOPE (AFM) APPLICATION HAS BEEN STUDIED IN THE AMPLITUDE MODE. PIEZOELECTRIC LAYER IS PLACED PIECEWISE AND AS AN ACTUATOR ON NMC. CONTINUOUS BEAM MODEL HAS BEEN CHOSEN FOR ANALYSIS WITH REGARD TO THE GEOMETRIC DISCONTINUITIES OF PIEZOELECTRIC LAYER ATTACHMENT AND NMC’S CROSS SECTION. THE FORCE BETWEEN THE TIP AND THE SAMPLE SURFACE IS MODELED USING LEONARD-JONES POTENTIAL. ASSUMING THAT CANTILEVER IS INCLINED TO THE SAMPLE SURFACE, THE EFFECT OF NONLINEAR FORCE ON NMC IS CONSIDERED AS A SHEARING FORCE AND THE CONCENTRATED BENDING MOMENT IS REGARDED AT THE END. NONLINEAR FREQUENCY RESPONSE OF NMC IS OBTAINED CLOSE TO THE SAMPLE SURFACE USING THE DYNAMIC MODELING. IT IS THEN BECOME CLEAR THAT THE DISTANCE AND ANGLE OF NMC, THE PROBE LENGTH, AND THE GEOMETRIC DIMENSIONS OF PIEZOELECTRIC LAYER CAN AFFECT FREQUENCY RESPONSE BENDING OF THE CURVE.