A new type of micromixer for rapid mixing was developed based on mixing by both kinetic energy and molecular diffusion of fluids. The rapid mixing was realized by the collision of micro segments, which were divided into several streams in the radial, at the center of the mixer. The excellent performance of the developed micromixer was confirmed by examining the Villermaux/Dushman reaction and the precipitation of polymer particles by phase separation. From these results, it was clarified that the rapid mixing was driven by both the breaking of micro segments under a high shear rate and instant molecular diffusion between micro segments. In addition, the mixer had a high throughput and corresponded to a wide range of flow rate ratios of fluids. Thus, it is expected that the proposed design concept for micro mixing will give us an efficient micro processing route in the future.

A new type of microreactor for fine particle production was developed to achieve stable continuous production, precise control of particle properties (such as particle size, distribution, and shape), and high throughput. The proposed microreactor, the annular multi-lamination microreactor, had an annular five-layer structure in a column at the center of the microreactor. By utilizing the microreactor, the crystallization of fine silver halide particles was examined under various operational conditions. From these results, optimum structures and operation methods for the high-throughput production of fine particles, which do not cause clogging of the microchannel, were determined. In addition, we give a simple method of equaling-up for industrial production. Thus, it is expected that the concepts of design, operational method, and equaling-up shown here can be incorporated into practical microreaction technology in the industrial field of fine particle production.