Motion Controller for Atomic Force Microscopy Based Nanobiomanipulation
ABSTRACT Nanomanipulation with Atomic Force Microscopy (AFM) is one of the fundamental tools for nanomanufacturing. The motion control
of the nanomanipulation system requires accurate feedback from the piezoelectric actuator and a highfrequency response from
the control system. Since a normal AFM control system for scanning motion is not suitable for control of arbitrary motion,
we therefore modified the hardware configuration to meet the demand of nanomanipulation control. By identifying the necessary
parameters using system identification methods, we built up a new dynamic model for the modified configuration. Based on the
new model and configuration, we designed and implemented a control scheme as motion controller for AFM nanomanipulation operation.
The aims are to analyze various factors in the control of the AFM-based nanomanipulation system. By integrating the original
AFM controller with the external Linux real-time controller, we achieved a stable system with high-frequency response. Several
problems have been addressed based on the new control scheme, such as high frequency response, robust feedback control and
non-linearity, etc. Finally this Multiple-Input Single-Output (MISO) system is validated by a real-time nanomanipulation task.
It is proved to be an effective and efficient tool for the controlling of the nanobiomanipulation operation by cutting the
intercellular junction of human keratinocytes.
SourceAvailable from: Ning Xi[Show abstract] [Hide abstract]
ABSTRACT: Nanomanipulation using Atomic Force Microscope (AFM) has been extensively investigated for many years. However, control of tip position during nanomanipulation is still a major issue because of the deformation of the cantilever caused by manipulation force. The softness of the conventional cantilevers also cause the failure of the manipulation of relatively large and sticky nano-object because the tip can easily slip over the nano-object. In this paper, an active atomic force microscopy probe is used to solve these problems by changing the cantilever’s flexibility or rigidity through different control strategies in imaging and manipulation modes respectively. During imaging mode, the active probe is controlled to bend up with respect to the interaction force between the tip and samples, thus making the tip response faster and increase the imaging speed. During manipulation mode, the active probe is controlled to bend down with respect to the interaction force between tip and the samples; thus increasing its nominal rigidity to avoid tip slipping over object. A detailed model of the active probe is presented in this paper and the controller designed based on the proposed active probe model is also implemented on the augmented reality system, which is an AFM based nanomanipulation system with both real-time visual and haptic feedback. The simulation results for the control strategies and the preliminary experimental results for the AFM based nanmomanipulation verified the validity of the model and effectiveness of the controller.Robotics and Automation, 2005. ICRA 2005. Proceedings of the 2005 IEEE International Conference on; 05/2005
Conference Paper: Modeling and Control of AFM-based Nano-manipulation Systems[Show abstract] [Hide abstract]
ABSTRACT: This paper develops a model and control scheme for nano-manipulation systems based on atomic force microscopes (AFM). The model includes the micro-cantilever's and piezotube actuator's coupled dynamics. An identification-based controller is proposed for piezotube scanner positioning accounting for the piezotube's nonlinear sensitivity and axes coupling. A novel robust adaptive controller is developed to compensate for large parametric uncertainties including time varying and switching parameters due to probe-surface contacts as well as time varying and impulsive forces due to contact and impact. Discussions and simulations are presented for typical nano-manipulation tasks.Robotics and Automation, 2005. ICRA 2005. Proceedings of the 2005 IEEE International Conference on; 05/2005
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ABSTRACT: Nanomanipulation with atomic force microscopes (AFMs) for nanoparticles with overall sizes on the order of 10 nm has been hampered in the past by the large spatial uncertainties encountered in tip positioning. This paper addresses the compensation of nonlinear effects of creep and hysteresis on the piezo scanners which drive most AFMs. Creep and hysteresis are modeled as the superposition of fundamental operators, and their inverse model is obtained by using the inversion properties of the Prandtl-Ishlinskii operator. Identification of the parameters in the forward model is achieved by a novel method that uses the topography of the sample and does not require position sensors. The identified parameters are used to compute the inverse model, which in turn serves to drive the AFM in an open-loop, feedforward scheme. Experimental results show that this approach effectively reduces the spatial uncertainties associated with creep and hysteresis, and supports automated, computer-controlled manipulation operations that otherwise would fail.IEEE Transactions on Automation Science and Engineering 05/2008; DOI:10.1109/TASE.2007.895008 · 2.16 Impact Factor