The Many Facets of Nanotechnology [Highlights]

I first heard the word "nanotechnology" probably in the late 1980s, when the field was largely unknown and just beginning to sprout. Working with electrochemists in the early 1990s, I stumbled on a process for creating interesting patterns of nanoscale undulations on the surface of a commercially sourced aluminum foil using electropolishing. When the foil is electropolished in a suitable mixture of perchloric acid, butyl cellusolve, ethanol, and distilled water at certain voltages and for certain durations, these patterns spontaneously appear on the surface [1]. Examples are shown in Figure 1. Some of these patterns, like the ones that are formed after electropolishing at 50 V for 10 s, or 60 V for 30 s, are interesting in that they are well-ordered arrays of stripes and mounds. The explanation for their formation is not simple and involves the nonlinear dynamics of chemical processes that were first explained by my colleagues Prof. Albert Miller and Prof. Hseuh-Chia Chang from the University of Notre Dame [2], [3]. These patterns were interesting in their own right but did not immediately lead to anything very useful. However, something else did.