This third of three volumes includes papers from the second series of NODYCON, which was held virtually in February of 2021. The conference papers reflect a broad coverage of topics in nonlinear dynamics, ranging from  traditional  topics from  established streams of research to those from  relatively unexplored and emerging venues of research. These include·         Complex dynamics of COVID-19: modeling, prediction and control ·         Nonlinear phenomena  in bio-systems and eco-systems   ·         Energy harvesting   ·         MEMS/NEMS           ·         Multifunctional structures, materials and metamaterials ·         Nonlinear waves     ·         Chaotic systems, stochasticity, and uncertainty