Researchers from across Europe have developed a single molecule that can be used for data storage using a scanning electron microscope.
The molecule is around five square nanometres in size which could offer data storage density of around 41Tb/cm 2 (256 Tb/in 2), around 100 times the storage density of current hard drives.
The team from KU Leuven, the Max Planck Institute for Polymer Research, Freiburg Centre for Interactive Materials and Lancaster University, see the paper in the journal Angewandte Chemie as a proof of concept for organic salts. These can be written, read and erased, at room temperature and in normal air pressures.
The lab experiments used small electric pulses in a scanning tunnelling microscope to switch individual molecules from bright to dark (shown above). They were also able to read and erase the information afterwards.
During the switching, the electric pulse changes the way the cation and the anion in the organic salt are stacked together, and this stacking causes the molecule to appear either bright or dark. Apart from the switching itself, also the spontaneous ordering of the molecules is crucial: through self-assembly, they find their way into a highly ordered structure (a two-dimensional crystal), without the need for expensive manufacturing tools.
"There is an entire list of properties that a molecule has to possess to be useful as a molecular memory. Apart from being switchable in both directions under ambient conditions, it has to be stable for a long time in the bright and dark state, and also spontaneously form highly ordered layers that are only one molecule thick, in a process called self-assembly. Ours is the first example that combines all these features in the same molecule," said Dr Stijn Mertens, Senior Lecturer in Electrochemical Surface Science at Lancaster University and lead researcher on the study.
The team includes Kang Cui from KU Leuven and the University of Jinan; Kunal Mali and Steven De Feyter