  DNA-coated colloids can self-assemble into an incredible diversity of crystal
structures, but applications of this technology are limited by poor
understanding and control over the dynamical crystallization pathways. To
address this challenge, we use microfluidics to quantify the self-assembly
dynamics of DNA-programmed colloidal crystals, from thermally-activated
nucleation through reaction-limited and diffusion-limited phases of crystal
growth. Our detailed measurements of the temperature and concentration
dependence of the kinetics at all stages along the crystallization pathway
provide a stringent test of classical theories of nucleation and growth. After
accounting for the finite rolling rate of micrometer-sized DNA-coated colloids,
we find that modified versions of these classical theories quantitatively
predict the absolute nucleation and growth rates. We conclude by applying our
model to design and demonstrate protocols for assembling large single crystals,
including crystals with pronounced structural coloration, an essential step in
the creation of next-generation functional materials from colloids.
