Tiny copper wires can be built in bulk and then "printed" on a surface to conduct current, transparently (Image: Benjamin Wiley, Duke Chemistry)
The latest flat-panel TVs and computer screens produce images by an array of electronic pixels connected by a transparent conductive layer made from indium tin oxide (ITO). ITO is also used as a transparent electrode in thin-film solar cells. But ITO has drawbacks: it is brittle; its production process is inefficient; and it is expensive and becoming more so because of increasing demand. One potential alternative is to use tiny copper nanowires and researchers have now perfected a simple way to make these in quantity. The cheap conductors are small enough to be transparent, making them ideal for thin-film solar cells, flat-screen TVs and computers, and flexible displays.