High performance microreactor for rapid fluid mixing and redox reaction of ascorbic acid

A novel micro device with a mechanism of spHt and recombination (SNR) for rapid fluidic mixing and reaction, named a SNR mu-reactor, was designed, fabricated and systematically analyzed. This SNR mu-reactor possessing an in-plane dividing structure requires only simple fabrication. We investigated this reactor and compared it numerically and experimentally with a slanted-groove micromixer (SGM). From the numerical results the mixing indices and mixing patterns demonstrated that the mixing ability of the SNR mu-reactor was much superior to that of the SGM. From a mixing test with phenolphthalein and sodium hydroxide solutions, the mixing lengths of the SNR mu-reactor were less than 4 mm for a Reynolds number over a wide range (Re = 0.1 - 10). From a comparison of mixing lengths, the results revealed also that the SNR mu-reactor surpassed the SGM in mixing performance by more than 200%. As a reaction length is a suitable test of the performance of a reactor, we introduced a redox reaction between ascorbic acid and iodine solutions to assess the reaction capabiHty of these micro devices; the reaction lengths of the SNR mu-reactor were much shorter than those of a SGM. The SNR mu-reactor has consequently a remarkable efficiency for fluid mixing and reaction.