This book elucidates information regarding the low Reynolds number aerodynamics. It discusses the recent advancements and trends in the low Re number aerodynamics, transition from laminar to turbulence, unsteady low Reynolds number flows, experimental studies, numerical transition modelling, control of low Re number flows, and MAV wing aerodynamics. It includes contributions by fluid mechanics and aerodynamics scientists and engineers proficient in their respective fields. The studies included in the book demonstrate significant new methods for the realization of the functions of MAV and wind turbine blades.