Some recent results: i) The combined use of atomic force microscopy (AFM) and electron microscopy allowed us to experimentally determine for the first time the reversible pathway and intermediates of assembly and disassembly of a structurally simple spherical virus (Fig.1). ii) Using mutational analysis and the determination of mechanical properties of virus particles by AFM we have discovered a relationship between genetic changes that alter the mechanical stiffness of virus particles and changes in the propensity of the latter to undergo conformational changes related to the infection process (Fig.2). iii) we have characterized the structure, dynamics and mechanical properties of a bidimensional nanocoating made by self-assembly of the HIV capsid protein on a solid matrix. These and other studies by our group have implications for a better understanding of processes essential for viral infection, the design of new antivirals that may inhibit these processes, and the development of nanoparticles and bidimensional biomaterials with improved mechanical properties for applications such as targeted drug delivery or tissue regeneration.