Nanotube memory

Working with an international group of researchers, Prof Gehan Amaratunga from Cambridge University has produced a novel memory device that is set to rival transistor-switched silicon-based memory.

The most common type of memory in use today is volatile random-access memory (volatile RAM), which requires a power source to store data. Volatile RAM may be divided into two types: dynamic and static (DRAM and SRAM). In DRAM each memory cell can consist simply of one capacitor and one transistor. The capacitor holds the bit of information, the transistor acts as a switch, letting the control circuitry on the chip read the capacitor or change its state.

Reading the state of the capacitor destroys the information in it and so the read operation must be followed by a write operation in which the state of the capacitor is restored. The capacitor consists of two charged layers separated by an insulator. The capacitor leaks charge and the information eventually fades unless the capacitor charge is refreshed.