Researchers have created a functional integrated circuit smaller than a grain of salt. This circuit is a broadband frequency mixer which according to IBM researcher Yu Ming Lin is “one of the most fundamental and important circuits in essentially all wireless communication devices and equipment.”
The new circuit design is made of graphene, a crystalline material which is made with a single layer of carbon atoms. Graphene is an exciting material for researchers because it can be stretched like rubber and is an excellent conductor of heat and electricity. When compared with silicon, a transistor made from graphene can be less expensive, demand less energy and reduce size demands, ideal for portable devices.
Graphene also has potential for other products, such as lighter body armor and even touch screen displays. Lin added “This is a circuit component that has a real function, a practical use in a real application, for example the cellphone. The significance is, because of the integration, the entire circuit can be very small; in this case less than 1 millimeter squared.”
IBM described how they allowed the integration of graphene with other components. “In this demonstration, graphene is synthesized by thermal annealing of SiC wafers to form uniform graphene layers on the surface of SiC. The fabrication of graphene circuits involves four layers of metal and two layers of oxide to form top-gated graphene transistor, on-chip inductors and interconnects.
The circuit operates as a broadband frequency mixer, which produces output signals with mixed frequencies (sum and difference) of the input signals. Mixers are fundamental components of many electronic communication systems. Frequency mixing up to 10 GHz and excellent thermal stability up to 125°C has been demonstrated with the graphene integrated circuit.”
KitGuru says: a very exciting technology and one which will have far reaching potential