MEMS Micromixer for Ultra Fast Mixing of Fluids

Rapid fluid mixing in microchannels has been a perennial quest in microfluidics for over 30 years. Presented here is an ultrafast MEMS-based mixer predicated on a rotating turbine. The turbine is capable of 30k rpm with mixing speeds of $ . The mixer is well suited to any application requiring high speed fluidic mixing but is ideally suited to the study and control of fast sequential chemical reactions, or the synthesis of kinetically controlled, metastable compounds [1]. Here, the preliminary MEMS mixer design, fabrication, and characterization are presented. To demonstrate the utility of the MEMS mixer, stable monodispersed silver nanoparticles, 1.1nm-8.0nm in diameter were synthesized using Ag(NO 3 ) and NaBH 4 to quickly nucleate the nanoparticles. Ligand capping at precision controlled times, 1ms to several seconds after initial nucleation with borohydride, quenched the reaction and produced nanoparticles of controlled diameters and dispersity.