Convective flow reversal in self-powered enzyme micropumps

摘要: Surface-bound enzymes can act as pumps that drive large-scale fluid flows in the presence of their substrates or promoters. Thus, enzymatic catalysis be harnessed for “on demand” pumping nano- and microfluidic devices powered by an intrinsic energy source. The mechanisms controlling have not, however, been completely elucidated. Herein, we combine theory experiments to demonstrate a previously unreported spatiotemporal variation behavior urease-based uncover behind these dynamics. We developed theoretical model transduction chemical into mechanical flow systems, capturing buoyancy effects due solution containing nonuniform concentrations substrate product. find qualitative features depend on ratios diffusivities δ = D P / S expansion coefficients β reaction ( ) product ). If > 1 (or if ), unexpected phenomenon arises: direction reverses with time distance from pump. Our experimental results are agreement show both speed i enzyme activity coverage, ii vary pump, iii evolve time. These findings permit rational design accurately control without external power sources, enabling effective, self-powered fluidic devices.