The Fabrication Of Ordered Colloidal Crystal Microstructures By Soft Lithography

The fabrication of ordered microstructures is of importance to much of modern science and technology, which thus actively drives the development of various patterning technologies besides photolithography. Soft lithography, encompassing many flexible methods, has become one of the most robust and versatile non-photolithographic routes to ordered microstructures. The success of soft lithography relies on the use of a poly(dimethylsiloxane) (PDMS) elastomer as a stamp, mold, or mask, which ensures the conformal contact between surfaces of the PDMS and substrates of interest and the easy release without destroying the formed microstructures. By flexibly applying different methods of soft lithography, a variety of materials (such as organic molecules, proteins, colloids, metals, and polymers) could not only be transferred from the surface of a PDMS stamp to the specific area of a substrate, but also be selectively removed from the substrate surface to the PDMS stamp surface using a lift-up process. Colloidal crystals made of polymer or inorganic microspheres represent a new class of advanced materials that have many potential applications in fields such as photonics, optics, and sensing. Large number of methods have been developed to introduce some specific microstructures into the colloidal crystals for their promising device application. Although some of these methods are efficient in controlling the size, structure, and crystalline orientation of...