Since the silicon computer chip was invented in 1961, silicon has been the basis of basically every electronic gadget, from computers to electric cars. And while it helped transform the world, silicon doesn't actually work particularly well—especially when it comes to energy use.
Silicon runs hot, and just keeping the material cool enough for electronics to work ends up using a lot of energy; in a massive data center, around half of the power footprint comes from cooling. In a smartphone or laptop, the parts needed to keep the electronics cool take up so much space that it's hard to keep making gadgets smaller (Moore's Law, the idea that computer chips will pack on twice as many transistors every two years, and become twice as fast, is almost dead in part because of silicon's heat problem).
One startup thinks lab-grown diamonds—which can eliminate 90% of the energy lost by silicon—are the answer. Because a semiconductor designed with diamond instead of silicon can run five times hotter and deliver a million times more electrical current, diamond chips could make devices smaller and lighter, while also saving energy.
The technology could also avoid a large portion of electronic waste by eliminating cooling fans and heat sinks. "Not only do these cooling fans fill up the landfill quite easily, only about 10% to 15% of these materials are actually recycled," says Adam Khan, founder and CEO of Akhan Semi, the diamond-making startup.
Despite the prices at jewelry stores, diamonds actually aren't expensive to make. "A lot of people say silicon is made of sand, sand is very cheap," says Khan. "Well, diamond is made from methane, which is the most abundant molecule in the universe. So it's really because silicon is so utilized worldwide that the costs are so low at the system level."
Because it costs so much to keep silicon cool, Khan says that it's already becoming cheaper to use diamond (and other similar advanced materials, called wide-bandgap semiconductors), instead. And while Akhan currently buys methane to make the diamonds from an ordinary supplier, it may eventually be possible to use wasted methane gathered from farms or other sources of pollution.
Making the diamond chips also uses 20% less water than making a comparable silicon chip.
The startup's first products add diamond components to existing silicon platforms, replacing heat sinks to save space and energy. Eventually, they believe that designers will begin using all-diamond semiconductors.
Khan says that the new chips could also change the type of devices that it's possible to make—like completely transparent electronics. A phone that uses a glass display (or sapphire, like the iPhone 6), could add diamonds to the display instead of using a separate circuit board.
"You're talking about thinner devices, but they're actually more useful in that you're directly displaying images from the material on the glass," he says. "It's not just that we're making existing materials better, but we're also enabling the next generation of design."