High-speed pulsed mixing with high-frequency switching of micropump driving and its application to nanoparticle synthesis

In this study, we proposed a novel mixing method using alternate pulsed flows from three inlet channels with piezoelectric valveless micropumps. It was experimentally and analytically confirmed that the proposed pulsed mixing of two solutions increased mixing speed with increasing the switching frequency of up to 400 Hz. The mixing time of 3.6 ms for 90 % mixing ratio of two solutions was achieved experimentally at the switching frequency of 400 Hz. The further increase in the mixing speed up to 800 Hz was analytically confirmed. As its application, gold nanoparticle was synthesized using the proposed method and the uniformity of particle sizes increased with the mixing speed.