Graphene nano-ribbons give a major boost to the sensitivity of sensors

Researchers from the University of Nebraska-Lincoln, University of Illinois at Urbana-Champaign, and Russia’s Saratov State Technical University have shown that adding a graphene nanoribbons to gas sensors can significantly increase their sensitivity compared to traditional ones.

GNRs improve efficiency of gas sensor imageThis rendering shows gas molecules widening the gaps between rows of the team's GNRs. This was proposed as a partial explanation to how the nano-ribbons grant sensors an unprecedented boost

The team integrated the nano-ribbons into the circuity of the gas sensor where it reportedly responded about 100 times more sensitively to molecules than did sensors featuring even the best performing carbon-based materials. “With multiple sensors on a chip, we were able to demonstrate that we can differentiate between molecules that have nearly the same chemical nature,” said the study author and associate professor of chemistry at the University of Nebraska. “For example, we can tell methanol and ethanol apart. So these sensors based on graphene nano-ribbons can be not only sensitive but also selective”.

MIT and Johns Hopkins team manages to make graphene self-fold into 3D shapes

Researchers with Johns Hopkins University and MIT have shown a way to cause flat sheets of graphene to self-fold into 3D geometric shapes. The group explains how they prepared the sheets and then used heat to cause them to fold. The ability to create 3D objects from sheets of graphene can advance opportunities in fields like sensors, wearables and more.

Graphene can be folded into 3D shapes image

In their work, the researchers developed a micro-patterning technique that leads to the flat graphene sheets bending along predesignated lines when heat is applied, causing the sheet to form into shapes. The new method not only preserves the intrinsic properties of the graphene, but it was also found that the creases can cause a band gap in the graphene, which can be extremely useful.

Researchers manipulate graphene to bring it closer to transistor applications

Researchers at the U.S. Department of Energy’s Ames Laboratory successfully manipulated the electronic structure of graphene, which may enable the fabrication of graphene transistors that could be faster and more reliable than existing silicon-based transistors.

Ames Lab manipulates graphene image

The researchers were able to theoretically calculate the mechanism by which graphene’s electronic band structure could be modified with metal atoms. The work will guide experimentally the use of the effect in layers of graphene with rare-earth metal ions “sandwiched” (intercalated) between graphene and its silicon carbide substrate. Since the metal atoms are magnetic, the additions can also modify the use of graphene for spintronics.

Researchers develop an efficient and healthy laser-induced graphene foam lighting device

Researchers from the Institute of low temperature and structure research in Wroclaw, Poland, developed a new efficient white light source that uses graphene foam excitated by a continuous-wave laser. The laser opens up a bandgap in graphene which results in light emission that ranges from 360nm (UV) or 405nm (visible) to 980nm-1064nm (near-infrared).

Graphene foam based white-light source (wroclaw)

The researchers say that the light spectrum of this device is similar to the spectrum of the sun which is better than current light sources such as LEDs that offer light spectrum with strong peaks (the main problem is the strong blue light emission in LED lighting). This design can achieve a high efficiency (over 200 lm/W), high color rendering index (CRI > 99) and a broadband warm white color. The lifetime depends on the laser, which can be over 10,000 hours.

Valleytronics research advances thanks to bi-layer graphene

Researchers from Penn State University demonstrated a new device, based on bi-layer graphene, that provides an experimental proof of the ability to control electron-flow by the valley degree of freedom. Valleytronics is a new field of science that aims to create devices that use electron's valley degree of freedom (in a somewhat similar way to Spintronics that aims to do the same with electron spin).

Bi-layer graphene based valleytronics experiment (Penn State)

The device is built from bi-layer graphene. The researchers added an electric field perpendicular to the plane opens a bandgap in the bi-layer graphene, which then enables them to build valleytronics valves in a physical gap present in the device.

Versarien - Think you know graphene? Think again! Versarien - Think you know graphene? Think again!