The emergence of complex nano- and microstructures is of fundamental interest, and the ability
to program their form has practical ramifications in fields such as optics, catalysis, and electronics.
We developed carbonate-silica microstructures in a dynamic reaction-diffusion system that allow
us to rationally devise schemes for precisely sculpting a great variety of elementary shapes by
diffusion of carbon dioxide (CO2) in a solution of barium chloride and sodium metasilicate.
We identify two distinct growth modes and show how continuous and discrete modulations
in CO2 concentration, pH, and temperature can be used to deterministically switch between
different regimes and create a bouquet of hierarchically assembled multiscale microstructures
with unprecedented levels of complexity and precision. These results outline a nanotechnology
strategy for “collaborating” with self-assembly processes in real time to build arbitrary
tectonic architectures.