For the design of micro reactors, dimensionless numbers have a prominent role. The various Damkhler numbers are among the most important since they allow us to evaluate residence time, mixing, fluid heating, and heat transfer. According to the design principles for micro reactors: Dal=ReLcdhkcm1=ConvectivecomponentincreaseChemicalcomponentincrease=tReactiontreactor>1DaII=2Dmksdh=diffusivecomponentincreaseChemicalcomponentincrease=tReactiontmixing