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The US Office of Naval Research has been funding studies into molecular
memory (WO 01/52266). Previous attempts to do this, which used photochemical
dyes to record data, failed because the read/write heads moved too slowly. They
were also limited because the memory could only be stored on a flat film. The
ONR gets round this by sandwiching a layer of polymer between fluoropolymer film
that has a wire grid criss-crossing it. Applying voltages to selected pairs of
wires produces pulses at the crossing points. This oxidises the polymer,
altering the electrical resistance at that point to represent a 0 or a 1. The
process is reversible, and the layers can be stacked to form a block that can be
used like a memory chip.