Patterned Sol-Gel Structures by Micro Molding in Capillaries

Abstract

AbstractThe development of a variety of micro-optical chemical sensor and biosensor devices will rely on an ability to fabricate and effectively pattern physically and chemically sensitive materials. Toward this end, organically modified sol-gel materials are patterned onto a substrate using a benign technique called micro molding in capillaries (MIMIC). Closely spaced, organically modified silica ridges containing organic dyes are demonstrated. The mold consists of a micro channel-filled elastomeric master in contact with a glass substrate. Liquid sols fill the mold as a result of capillary action. A reservoir-channel system in the mold allows simultaneous casting of sols with different chemical compositions. After gelation, the elastomeric master is removed and sol-gel structures are left on the substrate. Cross-sectional dimensions of the ridges range from one to tens of micrometers, and can be centimeters in length. Because of the mild processing conditions, the method is especially attractive for solgel materials containing sensitive molecules such as indicator dyes and biomolecules. The technique holds promise for microfabricated sensor and integrated optics applications.