2011 Volume 68 Issue 8 Pages 532-539
Colloidal crystals, three-dimensional periodic arrays of monodisperse particles, have received considerable attention with respect to possible applications, particularly as photonic crystals. Colloidal crystals are conventionally fabricated on a substrate, and the film shape and size limits the utility of these crystals for many applications. In this comprehensive paper, a method for fabricating spherical gel-immobilized colloidal crystals using microfluidics is reported. The gel-immobilized colloidal crystal spheres or microcapsules with gel-immobilized colloidal crystal shells can be fabricated through the combination of microfluidics and photopolymerization. The diffraction color or the Bragg wavelength of the gel-immobilized colloidal crystals can be adjusted by varying the particle concentration before gelation and tuned by external stimuli after preparation. The gel-immobilized colloidal crystal shell has a higher sensitivity and wider range in the Bragg wavelength than that displayed by a bulk gel.
