Trinity College Dublin researchers produce graphene in quantity using mechanical exfoliation.
Just about everyone knows that the 1-atom thick wonder material, graphene, is poised to take over the world of electronics. Its electrical properties alone would allow manufacturers to build CPUs that could run in the 100GHz range, that’s how unusually great the material is. The only problem is, we do not know when this will happen due in part because it has always been difficult and expensive to manufacture the material in bulk.
Current methods of graphene production include reduction processes (usually in oxide form), sonication (graphene oxide film applied to a DVD and burning it in a DVD writer) and heating silicon carbide to high pressures (among a handful of other methods). The trend of producing graphene using these slow and inefficient methods may be over with, thanks to some clever researchers from Trinity College Dublin’s AMBER department.
Their method of producing the material in bulk is based on the first technique pioneered in 2010- using adhesive tape to grab layers of graphene, otherwise known as the mechanical exfoliation method. Instead of using ‘Scotch Tape’ to grab flakes of graphene, the team used a stabilizing fluid mixed with the material and fed it into a shear-mixer. The mixer shears off sheets of graphene at a sufficient size that qualifies at ‘industrial levels’, claiming that their exfoliation method can be achieved using a few millimeters of liquid up to hundreds of liters and more. This breakthrough could open the door to manufacturing graphene on enormous scales at reduced costs, allowing electronics manufacturers to incorporate the material into their next-gen products.
Will graphene allow us to truly have a flexible phone? Samsung thinks so.
One of those electronics manufacturers is already eying the material for truly flexible electronics. Graphene beats out silicon for electron mobility 100-times over and is more durable than steel, has incredible heat conductibility (meaning it dissipates heat very well) and flexible to boot, which is why Samsung is eyeing it for flexible displays, wearable computing and mobile devices.
The tech giant has collaborated with Sungkyunkwan University to develop a synthesis method of producing the material in bulk. Unlike the AMBER department’s exfoliation technique, Samsung has adopted the multi-crystal synthesis method to synthesis ‘large-area’ graphene into a single crystal on a semiconductor. Multi-crystal synthesis tends to reduce the electrical and mechanical properties of graphene, however the collaborative effort at developing the process of depositing a single crystal on a semiconductor at wafer-scale sizes has allowed the graphene to retain its properties.
To put it simply, their method of fabricating the wonder-material results in sheets of graphene at wafer size, making it possible to mass produce new electronics in the near future rather than decades from now. While the prospects for incorporating graphene into everyday electronics is becoming a reality, powering those devices is a whole different story but may be possible using something the Earth has an abundance of.
Chinese scientists use graphene and saltwater to produce an electrical charge.
Powering our mobile devices is typically done through a rechargeable Li-ion battery but that may soon change, thanks to some ingenious Chinese scientists. Humans have been using water for power as a renewable resource through the use of hydroelectric dams, however to gain a powerful enough charge, the dams need to be large. This presents a problem when the technology is scaled down, as generating electricity at small levels is wholly inefficient.
To that end, scientists have been investigating grabbing a charge at nano-scale levels using nano-structures. Scientists have found that a significant charge could be garnered by passing ionic fluids through a pressure gradient, however even that is limiting due to that pressure gradient needed. As luck would have it, the Chinese science team found that passing a saltwater droplet over a sheet of graphene could produce an electric charge without the need for a pressure gradient.
The team found that when a droplet of saltwater sat static on the material, they carried an equal charge on both sides, however when they slid the droplet from one side to the other, it generated measurable voltage along the way. In fact, they found the faster the droplet moved, the more voltage it creates! While the initial generated charge was only around 30-milivolts, it presents future options to power our mobile devices if it can be refined and developed upon. Until then, we will still have to use the tried and true Li-ion to listen to music, watch our favorite shows and converse with our friends.
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