But over the years, their storage capabilities, usually no more than 64 GB, haven't kept pace with all the movies, games, apps and other memory-hogging minutiae of modern digital life.
Many people keep stuff in the cloud, but that requires Wi-Fi access.
It's frustrating to have to delete music or videos every time you want to store something new on your phone. But thanks to some advances in memory design and construction, we may be about to expand our devices in a big way.
At Rice University, a team led by chemist James Tour has developed a breakthrough
in RRAM (resistive random-access memory) technology. Their RRAM uses silicon oxide, one of the most studied and abundant substances on Earth, the stuff of sand and glass.
"Because it's this amazing material, the industry understands it," Tour said, noting that the key to the scalability of the design is industrial availability. Indeed, Rice's RRAM can be manufactured at room temperature and relatively lower voltages compared with other versions.
RRAM is the next step for an industry
that's finding the limits to flash memory. Like flash, RRAM doesn't need continuous power. But it's also much faster, since it can be built into more versatile arrays and stacked into bigger pieces.
"You've got to get into the third dimension to pack up enough density in the memory" in order to keep the capabilities growing, Tour said. Flash memory has kept up with Moore's Law -- the ever-increasing power of microchips -- by giving more functionality to the devices on the chips, he says.
But RRAM does a better and more efficient job.
"It's this insatiable desire for memory that's driving all this," he said.
Tour's team is one of many working on the problem, though he believes his approach has an edge because of its use of silicon oxide instead of more exotic materials. Licensing is under way, he says, and prototypes will be further test the concept's viability.
But if everything pans out, phones with a terabyte of memory
-- that's 1,000 GB, enough to hold hundreds of feature-length movies -- are just the beginning, Tour says.
"Because silicon oxide is glass and it's transparent, we've built these on glass, we've built this on top of plastic, so it can even be part of the coating you're looking at through the screen," he said.
Tour believes it'll be a world like that portrayed in the movie "Minority Report," with flexible, rollable digital "newspapers" and writable smart windows.
Talk about expandable.