Storage Industry News

IBM's Millipede Demonstrates Terabit Storage Achievement

June 2002: The thermomechanical storage project code-named Millipede by IBM has demonstrated a data storage density of 1 trillion bits per square inch, the company announced – 20 times higher than the most dense magnetic storage currently available. To put Millipede's density into perspective, IBM has demonstrated enough storage space on a surface the size of a postage stamp to put 25 million printed textbook pages.

Millipede uses thousands of nano-size tips arranged similar to an atomic force microscope (AFM) to punch indentations into a thin plastic film coating a silicon substrate only a few nanometers thick. The indentations represent individual bits. In a way, Millipede rejects commonplace magnetic or electronic storage methods for an improved, updated version of the old "punch card" system of data processing developed more than 100 years ago.

Millipede offers two advantages over its punch card ancestor, however: 1) by making a series of offset pits that overlap so closely that their edges fill in the old pits, the Millipede concept can effectively erase unwanted data and become re-writeable, and 2) because of its nanoscale, it can store 3 billion bits of data in the space occupied by just one hole in a standard punch card.

IBM researchers, including Nobel laureate and IBM fellow Gerd Binning, are now exploring how low they can go. "Since a nanometer-scale tip can address individual atoms, we anticipate further improvements far beyond even this fantastic terabit milestone," Binnig said. "While current storage technologies may be approaching their fundamental limits, this nanomechanical approach is potentially valid for a thousand-fold increase in data storage density."

To demonstrate the terabit of storage, IBM researchers employed a single tip making indentations only 10 nm in diameter. While the concept has been proven with an experimental setup that used 1,024 tips, the team is building a prototype, due to be completed early next year, which deploys 4,096 tips working simultaneously over a 7 mm-square field.

Such dimensions would enable a complete high-capacity data storage system to be packed into the smallest format used now for flash memory. But while flash memory is not expected to surpass 1 to 2 gigabytes of capacity in the near term, Millipede could pack 10 to 15 gigabytes of data into the same tiny format, without requiring more power for device operation.

"The Millipede project could bring tremendous data capacity to mobile devices such as personal digital assistants, cellular phones and multifunctional watches," said Peter Vettiger, Millipede project leader. "In addition, we are also exploring the use of this concept in a variety of other applications, such as large-area microscopic imaging, nanoscale lithography or atomic and molecular manipulation."

While much of the work on the Millipede project came out of IBM's Zurich, Switzerland, Research Laboratory, the use of an AFM tip for the reading and writing of topographical features for data storage was pioneered in the early 1990s by researchers at the company's Almaden Research Center. At the time, reading and writing were demonstrated with a single AFM tip in contact with a rotating polycarbonate substrate.