Document Type : Research Paper
Robotic Research Laboratory, Center of Excellence in Exprimental Solid Mechanics and Dynamics, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, I. R. Iran
Contact mechanics is related to the deformation study of solids that meet each other at one or more points. The physical and mathematical formulation of the problem is established upon the mechanics of materials and continuum mechanics and focuses on computations involving bodies with different characteristics in static or dynamic contact. Contact mechanics gives essential information for the safe and energy efficient design of various systems. During manipulation process, contact forces cause deformation in contact region which is significant at nano-scale and affects the nano-manipulation process. Several nano-contact mechanics models such as Hertz, DMT, JKRS, BCP, MD, COS, PT, and Sun have been applied as the continuum mechanics approaches at nano-scale. Recent studies show interests in manipulation of biological cells which have different mechanical properties. Low young modulus and consequently large deformation makes their manipulation so sensitive. In this article small deformation contact mechanics models are used for biological cell, in air and liquid environment, then results will be compared with Tatara contact mechanics model which has been developed for hyperelastic materials with large deformation. Since biological cells are mostly modeled as viscoor hyper-elastic materials, this model will be more compatible with their condition. FE simulation has been done to investigate the applicability of these models and finite element approach in different ranges of deformations.