Papers by Author: Hua Wei Chen

Abstract: In contrast to microscale method (molecular dynamics) or macroscale method (FEM), multiscale modeling is a new, fast developing and challenging scientific field with contributions from many scientific disciplines in an effort to assure materials simulation across length/time scale. In this paper we propose MPM/MD handshaking method to establish multiscale modeling of thin film formation/nanocutting. First, the detailed handshaking method is presented for large scale simulation along with basic principles of the multiscale approach. Then, quantitative items: flatness, cutting force, adhesion between cluster and substrate, etc. are provided to avoid drawbacks of current qualitative manner. Finally, simulations are carried out to clarify the efficiency of system.

Abstract: One novel long-travel piezoelectric-driven linear micropositioning stage capable of moving in a stepping mode is developed. The stick-slip friction effect between flexure hinge actuation tips with a sliding stage is used to drive the stage step-by-step through an enlarged displacement of piezoelectric actuator. In order to enlarge the travel range, magnifying mechanism is optimally designed by use of flexure hinge and lever beam. Moreover, dynamic model of such stage is proposed by consideration of reset integrator stick-slip model. The simulation results show that the stage has considerable good dynamic properties.

Abstract: Along with the rapid development of semiconductor, photonics and ultra-precision engineering, ultra-precision positioning stages are becoming more necessary than ever. In this study, one novel XY micropositioning stage is proposed, in which bi-axis circular notch flexure and cantilever hinge mechanism are optimal designed as bearing to provide smooth and guided motion. The theoretical stiffness of stage is provided and verified by FEM analysis. Finally, the micro-positioning stage is built and its resolution is experimentally validated to be less than 4nm.