A dynamic preferred direction model for the self-organization dynamics of bacterial microfluidic pumpingSvenšek, Daniel (Avtor) Pleiner, Harald (Avtor) Brand, Helmut R. (Avtor) fluid dynamicsmicrofluidicsbacteriaIt is known that some flagellated bacteria like Serratia marcescens, when deposited and affixed onto a surface to form a “bacterial carpet”, self-organize in a collective motion of the flagella that is capable of pumping fluid through microfluidic channels. We set up a continuum model comprising two macroscopic variables that is capable of describing this self-organization mechanism as well as quantifying it to the extent that an agreement with the experimentally observed channel width dependence of the pumping is reached. The activity is introduced through a collective angular velocity of the helical flagella rotation, which is an example of a dynamic macroscopic preferred direction. Our model supports and quantifies the view that the self-coordination is due to a positive feedback loop between the bacterial flagella and the local flow generated by their rotation. Moreover, our results indicate that this biological active system is operating close to the self-organization threshold.20192019-03-06 08:30:32Neznano106572sl