|
چکیده
|
The advent of miniaturization and transition from the macro world to the micro/nano world has brought into existence materials with more ratio of area to volume. In transition from the macro world to the micro/nano world, surface forces such as friction and adhesion that were formerly less significant or even negligible are under solemn scrutiny. In this respect, various friction models have been developed by numerous researchers in an effort to model the governing conditions in the micro/nano manipulation. In this paper, nanoparticle displacement dynamic modeling and simulation in AFM-based manipulation is addressed using advanced friction models in the nano scale including HK and LuGre which are both on the basis of true contact surface. Moreover, the effect of accurate modeling on the process of manipulation is compared with the results of the previous model. In addition, critical force and time variations by using different friction models are analyzed under the influence of model parameters. Previous research entailed a simplification of nanoparticles manipulation modeling using modified Coulomb friction model and assuming apparent contact surface while in reality, true contact surface is much less than apparent contact surface due to the raggedness of surfaces. This causes a significant decrease in friction force and hence manipulation critical parameters. Implementing an accurate friction model upgrades the precision of the prior less complex models. Simulation results show that the predicted critical force necessary for the initiation of particle movement by HK and LuGre models are reduced by 15.87% and 22.22% respectively and the critical time by 50% and 75% respectively compared to Coulomb model.
|