Integrated extended-nano chemical systems on a chip
In a past decade, new research fields utilizing microfluidics have been formed. General micro-integration methods were proposed, and the supporting fundamental technologies were widely developed. These methodologies made various applications in analytical and chemical synthesis fields, and their superior performances such as rapid, simple, and high efficient processing have been proved. Recently, the space is further downscaling to the 101–102 nm scale (extended-nano space). The extended-nano space is located between conventional nanotechnology (100–101 nm) and microtechnology (>1 μm), and the research tools are not well established. In addition, the extended-nano space is a transient space from single molecules to bulk condensed phase, and fluidics and chemistry are unknown. For these purposes, basic methodologies were developed, and new specific phenomena in fluidics and chemistry were found. These new phenomena were applied to unique chemical operations such as concentration and ion selection. The new research fields are now being created which are quite different with those in microspace. In this tutorial review, we focus on the basic researches in extended-nano space and survey the fundamental technologies for extended-nano space and reported specific liquid properties. Then, several unique chemical operations utilizing the properties are introduced. Finally, we show the future perspectives by showing the problems to be solved and illustrating the applications in development and in near future.