Hu Shuiqing, Raman Arvind
Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
Phys Rev Lett. 2006 Jan 27;96(3):036107. doi: 10.1103/PhysRevLett.96.036107.
Chaotic oscillations of microcantilever tips in dynamic atomic force microscopy (AFM) are reported and characterized. Systematic experiments performed using a variety of microcantilevers under a wide range of operating conditions indicate that softer AFM microcantilevers bifurcate from periodic to chaotic oscillations near the transition from the noncontact to the tapping regimes. Careful Lyapunov exponent and noise titration calculations of the tip oscillation data confirm their chaotic nature. AFM images taken by scanning the chaotically oscillating tips over the sample show small, but significant metrology errors at the nanoscale due to this "deterministic" uncertainty.
报道并表征了动态原子力显微镜（AFM）中微悬臂梁尖端的混沌振荡。在广泛的操作条件下使用各种微悬臂梁进行的系统实验表明，较软的AFM微悬臂梁在从非接触模式到轻敲模式的转变附近会从周期性振荡分叉为混沌振荡。对尖端振荡数据进行仔细的李雅普诺夫指数和噪声滴定计算证实了它们的混沌性质。通过在样品上扫描混沌振荡的尖端拍摄的AFM图像显示，由于这种“确定性”不确定性，在纳米尺度上存在小但显著的计量误差。
