Design,Modeling,Analysis And Applicaion Of Piezoelectric-Driven Nanopositioning Stages

Providing nano-scale resolution and accuracy,nanopositioning stages have been widely used in various fields(e.g.,integrated-circuits(IC)manufacturing,ultra-high precision manufacturing).Driven by piezoelectric actuators and guided by compliant mechanisms,nanopositioning stages are used as an essential component in high precision positioning applications(e.g.,scanning probe microscopy(SPM),nano imprint lithography).Design of compliant stages,system modeling and identification considering nonlinear hysteresis and coupled dynamics,time-delay control for naopositioning,and the application of nanopositioning stages in nanoimprint lithography are studied in this dissertation.Firstly,a design and analysis method is proposed based on the Castigliano’s second theorem.With the statics analysis,the stiffness matrix of a compliant stage can be analytically expressed.Dynamic analysis and parameter optimization are subsequently developed.A 2 degree-of-freedom(DOF)nanopositioning stage with 100μm×100μm range and 323 Hz resonant frequency is then presented.Secondly,a decoupled identifcation stratege is proposed based on rate-independent assumption.A Direct integration method(DIM)is proposed to solve the Bouc-Wen nonlinear equation,gradient of the identification error with respect to(w.r.t)identifcation parameters is subsequently derived,the steepest descent method is then used for identifcaiton.The harmonic linearazation method is then used for lienar parameters identification.A proportional-integral-retarded(PIR)time-delay controller is proposed for trajectory tracking and positioing of the nanopositioning stage.Based on the proposed DIM,the stability analysis of the closed-loop system is developed.Simulation and experiments varified that the computational efficiency can be significantly improved.Based on the stability ananlysis,a gradient based optimization method is used to find the optimal controller parameter.Finally,a prototype of nanoimprint lithography(NIL)tool is presented.With the designed flexure based active orientation adjustment mechanism and a 6–DOF nanopositioning stage,a minimum of 30 nm pattern transfer capability and < 15 nm parallelism error are demonstrated by nanoimprint experiments.