The data-storage capacity of CDs and DVDs is constrained by their size, so a group of researchers has devised a continuous process that makes long sheets of a many-layered optical storage medium.

Kenneth Singer of Case Western Reserve University in Cleveland, Ohio, and his colleagues began by melting and stacking two polymer layers and then pushing them through a series of 'multipliers', each of which doubles the number of layers. After the multi-layer melt was spread into a thin but dense optical-storage film, it could be cut and formed into various shapes and sizes. The team then used a laser to write data on each of 23 layers.

The group hopes that the method will eventually produce low-cost optical data film hundreds of metres long that can store terabytes or even petabytes of data — roughly equivalent to one million DVDs.

Adv. Mater. http://dx.doi.org/10.1002/adma.201200669 (2012)