System Bits: July 22

All graphene is not the same
Widely touted as the most electrically conductive material ever studied, researchers at the University of Pennsylvania now understand that all graphene is not the same. With so few atoms comprising the entirety of the material, the arrangement of each one has an impact on its overall function.

The team has used an advanced microscope to study the relationship between the atomic geometry of a ribbon of graphene and its electrical properties since a deeper understanding of this relationship will be necessary for the design of graphene-based integrated circuits, computer chips and other electronic devices.

The Penn team collaborated with researchers at Brookhaven National Laboratory, the Université Catholique de Louvain in Belgium and Seoul National University in South Korea.

An illustration of a graphene nanoribbon shaped by the beam of a transmission electron microscope. (Source: University of Pennsylvania)

3D nanostructures for better nanoelectronics
According to engineers at Rice University, a 3D porous nanostructure would have a balance of strength, toughness and ability to transfer heat that could benefit nanoelectronics, gas storage and composite materials that perform multiple functions.

The team made this prediction by using computer simulations to create a series of 3D prototypes with boron nitride, a chemical compound made of boron and nitrogen atoms. They fused 1D boron nitride nanotubes and 2D sheets of boron nitride to make the 3D prototype.

They combined the tubes and sheets together to make them 3D, thus offering more functionality. In the 3D nanostructure, the extremely thin sheets of boron nitride are stacked in parallel layers, with tube-shaped pillars of boron nitride between each layer to keep the sheets separated.

Unlike graphene-based nanostructures, boron nitride is an electrically insulating material. Thus, the 3D boron nitride prototype has a potential to complement graphene-based nanoelectronics, including potential for the next generation of 3D semiconductors and 3D thermal transport devices that could be used in nanoscale calorimeters, microelectronic processes and macroscopic refrigerators.