CHAPTER 26

MINERAL RESOURCES

NO STONE UNTURNED

A bevy of unfamiliar minerals is crucial for our everyday technologies—but they come with a slew of problems

It’s hard to imagine a future that’s higher tech than the world we live in now, replete as it is with tablets, cell phones, and e-readers. But if you want a glimpse of what such a future might hold, take a peek into Mark Hersam’s lab at Northwestern University in Chicago. The engineering professor has developed a carbon-based material that promises to revolutionize the way we produce energy, not to mention the way we make a whole suite of electronic appliances. Imagine flexible solar tents that provide soldiers in the field with a steady, consistent supply of electric power, or solar-powered clothes that double as “wearable electronics,” and you’ll begin to get a sense of what makes Hersam’s work so exciting.

The carbon nanotubes he’s developed—tiny, tubular-shaped carbon molecules that resemble rolled-up pieces of chicken wire—are poised to replace indium, a naturally occurring element that is growing in demand but is, like many other natural resources, environmentally hazardous to mine. Indium has been the key ingredient in touchscreens and liquid crystal displays (LCDs), as well as in the solar cells that form the basis of solar power. Its exceeding softness and malleability make it ideal for creating thin, transparent semiconductors. But indium is rare in nature, and the explosion of LCD technology has threatened to make it rarer still. Hersam’s nanotubes, which are made of carbon, latex, and polystyrene (all cheap and readily available ingredients), and which conduct electricity as well as indium does, could provide an alternative.