New DVD-sized disc to hold 1 to 5 terabytes of data

The optical disc revolution started with CDs and then moved on to DVDs, and we're in the midst of the next-gen battle between HD DVD and Blu-ray. Since the birth of the CD 25 years ago, we've gone from 600MB to a whopping 50GB of storage capacity on these little, convenient and versatile discs.

But for those who desire more space on a highly portable medium, new technology from a company called Mempile in Jerusalem promises to blow these limits away. The company claims that they can store up to 1TB (1,000GB) on an optical disc with the same dimensions—only slightly thicker—than a regular DVD and will be able to store 5TB once the jump to blue lasers is made.

The 1TB disc is divided into 200 different layers, each comprising 5GB of storage space. Unlike standard multilayer DVDs, the layers aren't physically stacked and stuck together. The Mempile discs are solid and use a specially developed variant of the polymer polymethyl methacrylate (PMMA)—a mixture of Perspex, Lucite, and Plexiglass—known as ePMMA. It's this polymer that gives the discs a distinctive yellow color.

When recording data to the disc, the laser focuses on one of the virtual layers and, using a photochemical reaction, modifies only a part of the plastic to represent a "1" or leaves it alone to represent a "0". This approach uses three dimensions in the polymer to store data rather than the two dimensions used by DVD. The technology is currently limited to WORM (write once, read many) although the company hopes to have read/write drives available in the future.

Mempile was incorporated as a company in 2000 in both the US and Israel, and it received an initial funding of $1 million from private investors and $3 million from the investment firm Millennium Materials Technologies. Further funding to the tune of $11.6 million came in 2004 from Kodiak Ventures, Israel Seed Partners, JVP, Hitachi CSK, PortView, and Alta Berkeley, so there is clearly some outside interest in the technology.

However, the key for Mempile will be whether or not the company can get the discs and drives to market in a reasonable timeframe. The idea itself is not new: other firms have been claiming to be developing this sort of technology for a few years now, but Mempile says that its prototypes are reaching 600-800GB now with 1TB coming soon, and it plans to follow the product up with a blue-laser version that could store up to 5TB. According to a company spokesperson, the discs have a life span of 50 years, and the drives themselves could be on the market in two to three years. By that time, either HD DVD or Blu-ray may have captured the optical storage market, so Mempile has its competition cut out for it.