Development of Viscoelastic Contact Theory for Cylindrical and Biological Micro/Nanoparticles

In the most contact theories such as Hertz, DMT and JKR, which are the most practical contacts models, biological particles are considered as a spherical elastic particle, which is not the best assumption. In this assumption, the history of loadings are not considered in that the history of strains and stresses will not analyzed properly. Therefore, in the first part of this paper, three models of elastic in spherical geometry have been developed to the viscoelastic models. By simulations and comparing the results with the experimental data of MCF-10A (breast-cancer cell), which is derived by Atomic Force Microscopy, it is revealed that viscoelastic models are more accurate than elastic models in the force-indentation curves. Then, according to the fact that most bacteria's geometry is cylindrical, contact theory for a sphere and cylinder have been developed and simulated for three groups of nanobacteria (Epidermidis, SallyVirus, and Aureus). By comparing simulations results with experimental data we observe that elastic models are not reasonable and contacts radius in viscoelastic model are smaller than they were for elastic models.