Analysis and Design of Magnetically Driven Nanomachines

The main aim of this paper is to set the theoretical framework needed for the analysis and design of magnetically driven nanomachines, namely, hybrid nanosystems obtained by assembling macromolecular complexes and magnetic nanoparticles (MNPs), whose functions can be activated and controlled by means of magnetic fields (MFs). Starting from the theoretical models, which describe the dynamics of an MNP in an applied MF, simplified analytical tools enabling to accurately describe the mechanical interactions between the nanoparticle and the applied field are derived. Exploiting these tools, the limits theoretically achievable by using MNPs as nanomotors, as well as the features of the nanoparticle and the MF required for this purpose, are determined. Then, three simple magnetically driven nanomachines of potential practical interest are considered, and their feasibility is analyzed, taking into account the presence of the thermal agitation.