Papers Published

  1. Tang, D. and Attar, P. and Li, A. and Dowell, E.H., Complex dynamics of a pyranose ring structure molecule attached to an Atomic Force Microscope, Nonlinear Dyn. (Netherlands), vol. 45 no. 3-4 (2006), pp. 283 - 303 [s11071-006-0508-9] .
    (last updated on 2007/04/10)

    Abstract:
    Dynamic numerical simulations were performed for a pyranose ring structure molecule attached to an Atomic Force Microscope (AFM) using a standard semiempirical potential energy surface model. The fundamental static force-extension behavior was first determined using a slow pulling base excitation at the AFM probe. The static force-extension curve displays a stiffness nonlinearity, both softening and hardening, that depends upon level of the pulling force. For the dynamic analysis, a single harmonic base excitation is applied to the AFM probe. A typical evolution process from periodic to aperiodic or chaotic motion obtained by varying the excitation frequency and amplitude is discussed. A strong chaotic response motion was generated for certain system parameters. The numerical analysis shows this chaotic response arises from a molecular structure conformational change

    Keywords:
    atomic force microscopy;chaos;molecular configurations;nonlinear dynamical systems;numerical analysis;organic compounds;potential energy surfaces;