A new nanotechnology take on the old punch-card storage system has enabled IBM Corp. researchers to demonstrate a data storage density of 1 trillion bits (1T bit) per square inch — 20 times higher than the densest magnetic storage currently available, IBM said in a statement Tuesday.

That density equates to storing 25 million pages of data on a surface the size of a postage stamp, or 15G bytes into a wristwatch-sized device, IBM said.

The system-code named Millipede-does away with magnetic or electronic means of data storage. Instead, Millipede uses thousands of sharp molecular-size tips to punch indentations representing individual bits into a thin plastic film. The indentations are just 10 nanometers, or millionths of a millimeter, in diameter. The technology used resembles that used in the atomic force microscope, invented in 1986 by IBM researcher Gerd Binnig, co-designer of the Millipede technology.

While resembling a tiny punch-card system, the Millipede indentations can be erased and rewritten a large number of times-tests have involved hundreds of thousands of write/erase cycles, IBM said.

Punch-card technology, invented over 110 years ago, was used to tabulate the results of the 1890 U.S. census. The new Millipede nanotech punch cards can pack 3 million bits into a hole the size of that used to store a single bit in the 19 th-century version.

Millipede technology, developed at IBM’s Zurich research laboratory, could begin replacing the current silicon-based flash memory cards in handheld computers and mobile phones by the end of 2005, but IBM said it has not yet decided on plans to release products based on the Millipede technology.