Salad Science: Devices Self-Assemble Using Oil-Water Repulsion
What happens when you add 64,000 tiny components to a base of oil and water? Depending on the nature of the components, you might end up with a delectable vinaigrette. University of Minnesota researchers found something even more tantalizing: a self-assembly method that is particularly effective at joining extremely small components in electronic devices. The U of M crew was attempting to leverage gravity into an active ingredient in self-assembly, dunking pre-etched substrates into liquids and hoping gravity would guide component materials to their proper places. But limited success in coaxing the components into place led to low success rates. So the team hatched a scheme to create a two-dimensional plane of component materials and put them together assembly-line style, and they did it with a little salad dressing science. The team coated the components -- in this case silicon and gold particles just a few tens of millionths of a meter...