Silicon computer chips have been on a roll for half a century, getting ever more powerful. But the pace of innovation is slowing. Today the U.S. military’s Defense Advanced Research Projects Agency (DARPA) announced dozens of new grants totaling $75 million in a program that aims to reinvigorate the chip industry with basic research into new designs and materials, such as carbon nanotubes. Over the next few years, the DARPA program, which supports both academic and industry scientists, will grow to $300 million per year up to a total of $1.5 billion over 5 years.

“It’s a critical time to do this,” says Erica Fuchs, a computer science policy expert at Carnegie Mellon University in Pittsburgh, Pennsylvania.

In 1965, Intel co-founder Gordon Moore made the observation that would become his eponymous “law”: The number of transistors on chips was doubling every 2 years, a time frame later cut to every 18 months. But the gains from miniaturizing the chips are dwindling. Today, chip speeds are stuck in place, and each new generation of chips brings only a 30% improvement in energy efficiency, says Max Shulaker, an electrical engineer at the Massachusetts Institute of Technology in Cambridge. Fabricators are approaching physical limits of silicon, says Gregory Wright, a wireless communications expert at Nokia Bell Labs in Holmdel, New Jersey. Electrons are confined to patches of silicon just 100 atoms wide, he says, forcing complex designs that prevent electrons from leaking out and causing errors. “We’re running out of room,” he says.