Storing bits of memory in nanotube switches.
The world of computer memory has been approaching an interesting crossroads. Most people are aware that we are rapidly approaching fundamental limits with both magnetic storage mediums like the hard drive, and in the fabrication of transistors through photolithography, which yields RAM and flash memory. Several areas of research, including fields like phase change momory
, may provide the opportunity to move away from both magnetic domains and transistors. To explore a different route to future memory systems, researchers went high-tech and put multiwalled carbon nanotubes (MWCNTs) to use—only to discover that they work through a surprisingly retro mechanism.
The researchers fabricated a device that was rather simple compared to the usual carbon nanotube fare that we cover in Nobei intent a single MWCNT was spread across a silicon substrate between two platinum electrodes. Although producing these devices is delicate work, it is a far cry from depositing the multiple layers of exotic materials that make up today's field-effect transistors. When a voltage was swept from negative to positive across the nanocable device, a clear transition between conductive and nonconductive states was observed. This transition proved to be nonvolatile; that is, they didn't have to apply a constant voltage in order to maintain the conductive or non-conductive state.
Obviously, this binary state behavior could act as the foundation for computer memory, so the researchers went to work exploring the properties of the device. Read/write operations were stable over thousands of cycles, and the state of the nanocable could read without changing it, meaning the storage of a bit was stable.
Moving into other performance metrics, they found that the MWCNT device was stable at ionizing radiations that cause normal electrical devices to fail, pointing to potential applications in extreme environments, like space. They remained stable over the course of several weeks in both vacuum and atmospheric conditions, and operated at temperatures that, if present in your laptop, would sear your favorite OEM's logo into your flesh. Read more at the source