Researchers over at Stanford University have managed to assemble transistors out of Graphene using DNA as a template thereby bringing the magic material closer to practical implementation in electronics products.
Team led by Zhenan Bao, a chemical engineering professor at Stanford, has established through their research that Graphene could indeed be used to make transistors that would pave a way through the clouded future of semiconductor based electronics. Silicon has been the default material for building electronic chips and to build more and more powerful chips, vendors have shrunk the size of the heart of these chips – transistors – to a size where heat and other interference will eventually start affecting and disrupting the inner workings of these chips.
This is where Graphene may come to the rescue as it has been proved that the material can be used to build smaller transistors that can operate consuming a lot less power as compared to silicon – however the problem here is cost-effective and efficient way of producing the material in bulk.
Bao and the other researchers believe that ribbons of Graphene would behave as semiconductor circuits if laid side-by-side. However, the main hurdle is to find a way to make one-atom think ribbons which are just 20 to 50 atoms wide. This is where the ingenuity of the process devised by the researchers at Stanford gets highlighted – using DNA as a template to build Graphene ribbons of required dimensions.
Why DNA? If looked at the physical properties of DNA, strands of DNA are long, thin and roughly of the same dimension of the Graphene ribbons that researchers wanted to assemble.
Using DNA’s physical and chemical properties researchers managed to build Graphene ribbons that could perform electronic tasks. Researchers used a solution of DNA derived from bacteria and dipped into it a tiny platter of silicon – a substrate for the experimental transistors – and combed the DNA into straight lines. These lines of DNA were exposed to copper salt solution and thanks to its chemical properties, the DNA absorbed the copper ions from the solution.
After this the silicon platter was heated while being bathed into Methane containing carbon atoms. Because of the chemical reaction induced by the heat, some of the carbon atoms were freed from both the DNA as well as the methane. These free atoms came together quickly and started forming honeycombs of Graphene.
Fung Ling Yap, former Stanford post-doctoral fellow said, “The loose carbon atoms stayed close to where they broke free from the DNA strands, and so they formed ribbons that followed the structure of the DNA.”
Anatoliy Sokolov, a team member and former Stanford post-doctoral fellow added, “We demonstrated for the first time that you can use DNA to grow narrow ribbons and then make working transistors.”
Using the process, Graphene can be built in bulk and once the refinements are worked upon, Yap is confident that the mechanism can be adopted for industrial production of Graphene. “Our DNA-based fabrication method is highly scalable, offers high resolution and low manufacturing cost,” said Yap.
“All these advantages make the method very attractive for industrial adoption”, Yap added.
[Source: Stanford Engineering]