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

Oct 10, 2017

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.

Honey can be used as a cheap and safe material for graphene manipulation

Sep 24, 2017

A rather accidental discovery was recently made that honey can serve as an effective, non-toxic substitute for the manipulation of the current and voltage characteristics of graphene. Researchers at the Space and Naval Warfare Systems Center Pacific (SSC Pacific) were investigating various dielectric materials they could use to fabricate a graphene transistor; First, the team tried to utilize water as a top-gate dielectric to manipulate graphene's electrical conductivity, but this approach was unsuccessful, so they proceeded with various compositions of sugar and deionized water, which still resulted in negligible performance. When testing honey, however, an unexpected scientific discovery was made.

Honey to help make graphene transistors image

The team describes how honey produces a nanometer-sized electric double layer at the interface with graphene that can be used to gate the ambipolar transport of graphene. "As a top-gate dielectric, water is much too conductive, so we moved to sugar and de-ionized water to control the ionic composition in hopes we could reduce conductivity," the team explained. "However, sugar water didn't work for us either because, as a gate-dielectric, there was still too much leakage current..... We decided to drop-cast honey on graphene to act as top-gate dielectric— I thought maybe the honey would mimic dielectric gels I read about in literature. To our surprise—everyone said it's not going to work—we tried and it did".

Researchers manipulate graphene to bring it closer to transistor applications

Aug 30, 2017

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.

Manipulating electron spin in graphene may enable ambient-temperature FETs

Jul 09, 2017

Researchers at Chalmers University, affiliated with the Graphene Flagship, have devised a graphene-based spin field-effect transistor with the ability to function at room temperature. The team used the spin of electrons in graphene and similar layered material heterostructures to fabricate working devices in a step towards combining memory devices and the logic of spintronics.

Graphene spintronics FETs image

The researchers demonstrated that the spin characteristics of graphene can be electrically regulated in a controlled way, even at an ambient temperature. In addition to possibly unlocking various probabilities in spin logic operations, this study also enables integration with magnetic memory elements in a device unit. If further advancements can assist in the production of a spin current without the need for charge flow, the amount of power needed will be considerably reduced, resulting in highly versatile devices.

Graphene-based transistor to potentially make ultra-fast computers

Jun 14, 2017

Researchers at the University of Central Florida, the University of Texas at Dallas and other collaborators have designed a graphene-based transistor which could be used to create an all-carbon spin logic design with the potential to someday lead to computers that are a thousand times faster and use a hundredth of the power.

UCF's GNR's for  graphene transistor image

The team found that by applying a magnetic field to a graphene ribbon, it is possible to change the resistance of current flowing through it. For this device, the magnetic field is controlled by increasing or decreasing the current through adjacent carbon nanotubes. Increasing or decreasing the strength of the magnetic field would also increase or decrease the flow of current through this new kind of transistor, much like a valve controlling the flow of water through a pipe.