Nanomechanical Characterization of Tobacco Mosaic Virus Superlattice with Novel Atomic Force Microscopy Methods

Abstract

Tobacco mosaic virus (TMV) has been widely studied due to its excellent properties. In order to utilize TMV superlattice, this thesis initiates the study on its mechanical properties. The elastic modulus of TMV superlattice was first assessed by means of AFM-based nanoindentation and extended JKR model. The consideration of adhesion involved in the interaction of the AFM tip and the surface of the sample results in more accurate measurement. The novel numerical process proposed in this thesis simplifies the fitting procedure. The viscoelasticity of TMV superlattice was also measured. The AFM was for the first time utilized to perform a transient viscoelastic experiment. An adhesive viscoelastic contact mechanics model was developed based on which the elastic moduli E, E2 and the viscosity η (Fig.4.5) are determined to be 3 GPa, 0.0213 GPa and 12.4 GPa.ms, respectively. This thesis can serve as novel examples to characterize the mechanical properties of nano-biomaterials.