Stanford engineers have demonstrated a number of post-silicon memory materials and technologies based on graphene. According to Ramin Skibba of Stanford News, the materials are capable of storing significantly more data per square inch – all while sipping a fraction of the energy consumed by current memory chips.
Image Credit: Stanford News
“A purified relative of pencil lead, graphene is formed when carbon atoms link together into sheets just one atom thick,” Skibba explained. “Atom-thin graphene is stronger than steel, as conductive as copper and has thermal properties useful in nanoscale electronics.”
Eric Pop, associate professor of electrical engineering at Stanford, described graphene as the “star” of the research, which comprised three separate experiments.
“With these new storage technologies, it would be conceivable to design a smartphone that could store 10 times as much data, using less battery power, than the memory we use today,” he confirmed.
Professor H.-S. Philip Wong expressed similar sentiments, noting that post-silicon memory chips may also transform server farms tasked with storing and delivering quick access to the vast quantities of data stored in the Cloud.
“Data storage has become a significant, large-scale consumer of electricity and new solid-state memory technologies such as these could also transform cloud computing,” said Wong.
One of the above-mentioned graphene-based experiments outlined in Nature Communications involved working with resistive random-access memory, or RRAM. More specifically, Wong, together with postdoctoral fellow Seunghyun Lee and PhD candidate Joon Sohn, demonstrated the potential of constructing non-volatile RRAM – while densely storing data without consuming more energy.
The two other graphene-based experiments – described in Applied Physics Letters and Nano Letters – involved phase-change memory.
“[In the Applied Physics Letters experiment] they used ribbons of graphene as ultra-thin electrodes to intersect phase-change memory cells, like skewers spearing marshmallows,” Skiba reported. “This setup also exploited the atomically thin edge of graphene to push current into the material, and change its phase, again in an extremely energy-efficient manner.”
In the Nano Letters paper, Pop and Wong included both the electrical and thermal properties of graphene in a phase-change memory chip. Interestingly, the two scientists used the surface of the graphene sheet to contact the phase-change memory alloy. Essentially, the graphene worked to prevent the heat from leaking out of the phase-change material, creating a more energy-efficient memory cell.
These studies, say Skibba, illustrate why graphene is far from just a laboratory curiosity.
“The material ‘s unique electrical, thermal and atomically thin properties can be utilized to create more energy-efficient data storage. Such properties do not exist in the silicon world, yet could potentially transform the way we store and access our digital data in the future,” he concluded.