Current data storage devices face a primary limitation in terms of the storage space that is allocated within each device. Data storage devices such as multimedia card (MMC), secure digital (SD) card, and extreme digital (XD) card are examples of current data storage devices that face this limitation.
Devices such as these are capable of nonvolatile memory storage as they still retain the ability to store information and data without a constant supply of electrical power. These devices, together with disks used in computers, are very suitable to hold information and data on a long-term basis. However, the storage size limitation still haunts manufacturers.
In this regard, a research team from Rice University has proposed the novel concept of using a strip of graphite approximately 10 atoms thick to form the platform of a new type of memory that would be able to offer massive amounts of storage space. This would serve applications such as computers, mobile phones and digital cameras.
Led by James Tour, professor of mechanical engineering and materials science, the research team has taken advantage of the excellent conducting properties of graphene. Once realised, they believe this memory device will offer significant advantages over Flash memory and the nonvolatile memory devices currently available in the market.
The use of graphene in memory devices is comparatively new, but could prove extremely beneficial. Graphene memory will increase the size of storage in a two-dimensional structure by a factor of five. The use of new switches that are managed by two terminals (as opposed to the conventional three) will also make three-dimensional memory a reality through the multiplication of the chip’s storage capacity.
Primarily a mechanical device, this memory device would consume almost zero power while it keeps data safe. One major significance will be the increase displayed in the on-off power ratio it offers. The current industry ratio is 10 to one – the amount of electrical current the circuit holds when it is on is 10 times the amount when it is off. However, the new invention could have a ratio of close to a million to one. This allows the researchers to create a much larger array, thereby increasing the storage space of the device.
Another significant breakthrough achieved is in the lifetimes of these devices, which are much longer than products available today. This is based on the results of degradation tests, where 20 000 cycles of testing did not damage or decrease the effectiveness of the device.
Application-wise, this invention would be useful for memory storage purposes in any product that requires data storage, such as computers, laptops, mobile phones and handheld game consoles. Ironically, research activities are currently being slowed down because the lab’s testing systems cannot keep up with the speed of the switches.
Commercialisation, together with a pilot plant setup, will take close to several years to materialise as the research team still needs to tweak more elements in the design of this device. Being able to scale up manufacturing techniques is another concern for the researchers, thus they would welcome industrial collaboration with those interested in this graphene-based memory device technology.
The abundance of carbon, and in particular graphene, on earth will aid the production of this memory device as it is not a new material that has to be created from scratch. While fabricating graphene commercially is troublesome, depositing it on a substrate through methods such as chemical vapour deposition (CVD) is an excellent example of processing made easy.
Tests and experiments have demonstrated that this graphene-based memory device can perform under extreme temperatures (based on high- and low-temperature tests) as well as extreme environments (based on results of radiation experiments).
Frost & Sullivan anticipates that as one of the biggest markets available today is the entertainment sector, which is driven by memory-based products such as digital cameras, video cameras and mobile phones, this breakthrough could enjoy significant success if it is successfully commercialised.