Boffins build Flash-like chip from graphite

Pencilling in a new design

By Tony Smith • Get more from this author

22nd September 2009 19:10 GMT

Scientists as Texas' Rice University have created a Flash-like non-volatile storage chip technology out of the same material used to put lead in your pencil.

Dubbed "graphitic memory", the technique involves placing sheets of graphite between electrodes. Put a specific voltage across the sheet and it cracks. You can use the crack to represent, say, a binary 1, the cracking process therefore being a write operation. If a higher voltage is applied to the sheet, the crack vanishes, so the cell enters a state that represents a binary 0.

Applying a lower voltage across the sheet allows you to detect whether it's cracked or not - in other words to read the memory cell's state.

The work was conducted by Rice chemistry professor James Tour, who revealed to MIT Tech Review that unlike other allotropes of carbon, such as the sheet-graphene or nanotubes, graphite is easy to deposit on silicon.

Since the cell is less complex than the transistors used to store data in Flash chips, graphitic memory could pave the way for cheaper storage too.

And more of it, since both the simplicity of the cell and its flat structure mean that it should be easy to layer cell upon cell to construct highly dense storage chips, Tour said.

The system operates at voltages lower than those used by Flash cells, he added, and graphitic memory's read and write speeds are both comparable to today's Flash equivalents.

That said, it's early days and work will be needed to demonstrate not only consistent behaviour and permanence of data storage, but also that the cell can indeed be used as the basis first of two- and then three-dimensional arrays of memory cells. ®