Hewlett-Packard researchers said Monday that they have built a 64-bit memory chip so small that more than 1,000 of them can fit on the end of a strand of hair.

"We've fabricated what is, at this point in time, the world's highest-density electronically addressable memory," R. Stanley Williams, director of quantum science research for HP Labs, said in a conference call.

By fitting 64 bits of data in one square micron of space, the equivalent of 6.4 Gbits per square centimeter, HP has packed in approximately 10 times the circuit density of the highest-density DRAM currently available on the market, Williams said.

The memory chip consists of an eight-by-eight grid of platinum wires, each only 40 nanometers wide. At each spot where wires intersect, a thin layer of organic molecules is sandwiched between them. By sending current through the wires, the molecules can be given an electrical charge and turned off or on to represent the one or zero in a bit of information.

Sixty-four bits of memory isn't enough for the chip to be used commercially, Williams said. But he predicts that within five years, chips based on the technology will be sold as nonvolatile flash memory for digital cameras and other portable devices, providing far more data storage than today's cards.

Those next-generation chips might even be cheaper to build than today's model, thanks to a new process used to build the prototype, says Phil Kuekes, a member of the HP Labs team that worked on the project. HP used traditional lithography techniques to construct a mold consisting of eight parallel lines. When pressed onto a silicon wafer, that creates a series of trenches, which are then filled with platinum to form the wires. A thin layer of electronically switchable molecules is deposited on top of that. Finally, the mold is rotated 90 degrees and pressed down again, making another eight wires and completing the circuitry.

This technique should let manufacturers quickly and cheaply "stamp out" chips, in much the same way a printing press works. Jokes Kuekes, "This is just nothing other than HP continuing in its role as a printing company."