From wikipedia: The progress of millipede storage to a commercially useful product has been slower than expected. Huge advances in other competing storage systems, notably Flash and hard drives, has made the existing demonstrators unattractive for commercial production. Millipede appears to be in a race, attempting to mature quickly enough at a given technology level that it has not been surpassed by newer generations of the existing technologies by the time it is ready for production.
The earliest generation millipede devices used probes 10 nanometers in diameter and 70 nanometers in length, producing pits about 40 nm in diameter on fields 92 μm x 92 μm. Arranged in a 32 x 32 grid, the resulting 3 mm x 3 mm chip stores 500 Mbits of data, resulting in an areal density, the number of bits per square inch, on the order of 200 Gb/in². IBM initially demonstrated this device in 2003, planning to introduce it commercially in 2005. By that point hard drives were approaching 150 Gb/in², and have since surpassed it.
More recent devices demonstrated at CeBIT in 2005 have improved on the basic design, using a 64 x 64 cantilever chips with a 7 mm x 7 mm data sled, boosting the data storage capacity to 800 Gb/in² per square inch using smaller pits. It appears the pit size can scale to about 10 nm, providing an areal density just over 1Tb/in². IBM now plans to introduce devices based on this sort of density in 2007. For comparison, the very latest perpendicular recording hard drives feature areal densities on the order of 230 Gb/in², and appear to top out at about 1 Tb/in². Semiconductor-based memories offer much lower density, 10 Gb/in² for DRAM and about 250 Mb/in² for Flash RAM.
Recently others have found how to reduce friction by 100 times in MEMS devices like Millipede. That can help to improve the reliability and operating life for Millipede devices. If Millipede can be commercialized next year, the cost of AFM and other microscope arrays could come down. The cost reduction would boost the development of more massively parallel arrays of microscopes. That development would boost early molecular nanotechnology capabilities. This is getting more powerful with improvement s to the tips of the microscopes. They have tips that end with one atom, which increases the accuracy and resolution.