Precision Marangoni-driven patterning.

A Marangoni flow is shown to occur when a polymer film possessing a spatially-defined surface energy pattern is heated above its glass transition to the liquid state. This can be harnessed to rapidly manufacture polymer films possessing prescribed height profiles. To quantify and verify this phenomenon, a model is described here which accurately predicts the formation, growth, and eventual dissipation of topographical features.

Oxygen limitation within a bacterial aggregate.

ABSTRACT Cells within biofilms exhibit physiological heterogeneity, in part because of chemical gradients existing within these spatially structured communities. Previous work has examined how chemical gradients develop in large biofilms containing >10(8) cells. However, many bacterial communities in nature are composed of small, densely packed aggregates of cells (≤ 10(5) bacteria).

Templated evaporative lithography for high throughput fabrication of nanopatterned films.

A new method for the fabrication of well-defined nanostructured deposits by evaporation-driven directed self-assembly of nanoparticles is proposed and studied theoretically. The technique comprises a film of suspended nanoparticles drying with its surface in contact with a topographically patterned membrane which promotes spatially varying evaporation, resulting in a patterned deposit. Membrane thickness and topography (in conjunction with the initial film height and concentration) allow the feature and residual layer dimensions to be controlled independently.