IBM RACETRACK MEMORY: stores data in a magnetic pattern on a nanowire such as the one shown. Pulses of electrical current use the spin of electrons to move the entire data pattern along the wire as though on a racetrack. Current passing across the wire (green arrow) is used to read or write data.
Courtesy of IBM Almaden Research Center

Gadget buyers today can purchase PCs, cell phones and mp3 players with significantly more memory than their predecessors for just a few dollars more than they paid a few years ago. To wit: you can purchase an 80-gigabyte iPod today for the same price (around $250) you paid for one with just 30 gigabytes of memory two years ago. But consumers are in for a rude awakening if technology makers fail to find a way to shrink memory components enough to continue packing more of them into ever-tinier gadgets.

Computers and other electronic devices use different types of memory to perform different functions. PCs use a hard disk drive, for example, to store large amounts of data for the long term and Random Access Memory (RAM)—also called "solid state" memory—to retain data outside the hard drive, where it can be accessed quickly and repeatedly. In an attempt to ensure that memory is not sacrificed with size, however, device makers are eyeing an experimental approach called "universal memory," which not only takes up less space but is also faster than the RAM now available.  Currently only a handful of companies are investing in the budding technology, but that could change as new forms of universal memory emerge, most notably IBM's "racetrack" memory and Nantero, Inc.'s nano RAM (NRAM).

These join slightly more mature—yet still unproven—universal memories such as magnetoresistive RAM (MRAM), which uses magnetic polarization to store information permanently on a device's microprocessor, and "phase change" memory, which stores data in a glassy substance called chalcogenide as it is heated and its atoms are rearranged.

Each type of solid-state memory (which includes static RAM, dynamic RAM and flash) has its benefits and drawbacks. "Because of cost, it's often impractical to have all three, so the designer needs to make hard choices and sacrifice something (such as speed, battery life, et cetera) and go with only one or two out of the three memory types," says Greg Schmergel, Nantero's co-founder, president and chief executive officer.

SRAM, often used for cache memory in microprocessors, can rapidly read and write data without sucking up a lot of power, but it cannot hold as much data as DRAM. DRAM, however, is slower than SRAM and requires more power, making it impractical for portable devices running on batteries. Flash's main advantage is that it retains information (such as an address book in a cell phone) even when the device is powered down, but it is not as fast or as durable as its counterparts, which means too much use will cause it to wear out and lose data.

To create NRAM, Woburn, Mass.–based Nantero places billions of carbon nanotubes on a silicon chip to store data. When an electrostatic force is applied, the carbon nanotubes move up and down to represent the 0s or 1s of data. The company has demonstrated, Schmergel says, that NRAM's approach has the speed and capacity to surpass other memory types and that it can be manufactured in existing chip-making facilities (called fabs). The question is whether major chipmakers such as Intel, Micron or Samsung can be persuaded that NRAM can be efficiently and reliably manufactured in high volume.