| Assembly of nanostructures has gained wide interest in the past decade for its possible applications in chemistry, physics, electronics and medical research. Nanostructures have shown unique properties that may revolutionize future technology, properties that are nearly unachievable at the macro or even microscales. Atomic Force Microscopes (AFMs) are the main instruments that bridge the gap between the nanoscale and the macroscale.;This thesis addresses an important issue in AFM: building precise and dimensionally well-defined nanostructures in a minimum amount of time. The AFM is viewed as an autonomous robot that maneuvers on the sample surface, locates desired nanoobjects, manipulates them into a desired location and meanwhile optimizes its entire task to achieve speed and precision. It is proved experimentally that the assembly of complicated structures consisting of large numbers of nanoobjects, which in the past took an experienced person a whole day to make, now can be built in minutes without any user interaction.;The first part of the thesis addresses the main issues that arise in precisely controlling the position of an AFM's tip with respect to the sample. The existing spatial uncertainties in the AFM range from the nonlinear behavior of the piezo scanner to the thermal drift of the mechanical components. A Kalman filter technique is introduced for the estimation and prediction of the drift effect. The piezo scanner's nonlinearities such as creep and hysteresis are modeled with the Prandtl-Ishlinskii operator and a feedforward controller is designed for compensating these effects. A novel method for the identification of nonlinear parameters is introduced and an integrated compensator for the entire set of AFM's uncertainties is designed and studied.;The last part of the thesis addresses specifically the manipulation dynamics and characteristics in AFM instruments. The issues that are important for achieving a successful automated manipulation are discussed. At the end, an open-ended line of research on the estimation of atomic interaction force using higher harmonics of cantilever vibrations with possible application in imaging biological materials is studied. |
