Nanometer-scale patterning of hard and soft interfaces: from photolithography to molecular-scale design

Many areas of modern materials chemistry, from nanoscale electronics to regenerative medicine, require design of precisely-controlled chemical environments at near-molecular scales. Most work on high-resolution interface patterning to date has focused on hard surfaces, such as those for electronics. However, design of interfaces for biological environments increasingly requires precise control over interfaces of soft materials, which is in many cases complicated by nano-to-microscale heterogeneity in the substrate material. In this Feature Article, we describe historical approaches to nanoscale patterning on hard surfaces, challenges in extension to soft interfaces, and an approach to molecular-scale hard and soft interface design based on self-assembled molecular networks, which can be assembled noncovalently on hard surfaces to generate nanometer-scale patterns, then covalently transferred to soft materials including PDMS and hydrogels.