This paper aims to simulate elastic and elastic-perfectly plastic contact theories for HT29 cancer cell based on atomic force microscopy (AFM). At first, The HT29 cancer cell image were taken using an atomic force microscope. Then, Hertz elastic model, and Chang elastic- perfectly plastic model simulation for HT29 cancer cell were compared to each other. Hertz Theory that the latter is unable to describe the contact behavior of very soft bio particles. Since in most of the work conducted to calculate mechanical properties and used elastic contact theories such as Hertz and JKR for soft particles manipulation, For the first time, Chang theories have been introduced to calculate contact mechanic of bio particles and simulate effective contact mechanics in bio manipulation based on atomic force microscopy. Comparing the results of the two contact theories showed that chang theory are large deformation ones which will resolve defects of previous theories such as Hertz.
