Computer hard drives of the future may consist of smart molecules. Researchers have discovered a molecular switch that can act as a transistor and has the potential to store binary information, such as units and zeros, used in classical calculations. It is reported by Angewandte Chemie International Edition.
The size of the molecule is about five square nanometers. This means that more than one billion molecules will be the thickness of a human hair. An international group of scientists behind this breakthrough believes that molecules like the ones they discovered can provide an information density of about 250 terabits per square inch, which is about 100 times the storage density of modern hard drives.
Although researchers do not expect the specific molecules they find to be used in real hard drives, the study is an important proof of concept that brings us closer to the brave new world of real molecular electronics.
During the study, organic salt molecules can be switched using a small electrical input so that they look either bright or dark, providing binary information. It is important to note that this information can be recorded, read, and deleted at room temperature and at normal air pressure. These are important characteristics for the practical application of molecules in computing storage devices. Most of the previous studies in the field of molecular electronics for similar applications have been carried out in a vacuum and at very low temperatures.
“There is a whole list of properties that a molecule must possess in order to be useful as molecular memory. In addition to switching in both directions under environmental conditions, it must be stable for a long time in the light and dark state, and also spontaneously form highly ordered layers with a thickness of just one molecule in a process called self-assembly. For the first time, we combined all these functions in one molecule. ”
Stein Mertens, Senior Lecturer in Electrochemical Surface Sciences at the University of Lancaster
In laboratory experiments, the research team used small electrical pulses in a scanning tunneling microscope to switch individual molecules from bright to dark. They could also read and erase information with the click of a button.
During the switchover, an electrical impulse changes the way the cation and anion in the organic salt are joined together, and this makes the molecule appear light or dark. In addition to the switching itself, spontaneous ordering of molecules is also important: due to self-assembly, they fall into the highly ordered structure of a two-dimensional crystal without the need for expensive production tools.