Millimeter-scale self-assembly and its applications

Self-assembly is a concept familiar to chemists. In the molecular and nanoscale regimes, it is often used as a strategy in fabricating regular 3D structures-that is, crystals. Self-assembly of components with sizes in the mum-to-mm range is less familiar to chemists; this type of self-assembly may, however, become technologically important in the future. In this size range, self-assembly offers methods to form regular 3D structures from components too small or too numerous to be manipulated by other means, and methods to incorporate function into these structures; it also offers simplicity and economy. This paper focuses on the use of self-assembly to build functional systems of components with sizes in the range from microns to millimeters. It compares the principles of self-assembly at the molecular and millimeter scales, reviews the possible applications of mesoscale, self-assembled systems, and outlines some of the most important issues in the use of self-assembly to build functional systems.