Electronics - Page 2

A new study, led by the Catalan Institute of Nanoscience and Nanotechnology (ICN2) along with the Universitat Autònoma de Barcelona (UAB) and other international partners like the University of Manchester (under the European Graphene Flagship project), presents EGNITE (Engineered Graphene for Neural Interfaces) - a novel class of flexible, high-resolution, high-precision graphene-based implantable neurotechnology with the potential for a transformative impact in neuroscience and medical applications. 

This work aims to deliver an innovative technology to the growing field of neuroelectronics and brain-computer interfaces. EGNITE builds on the experience of its inventors in fabrication and medical translation of carbon nanomaterials. This innovative technology based on nanoporous graphene integrates fabrication processes standard in the semiconductor industry to assemble graphene microelectrodes of a mere 25 µm in diameter. The graphene microelectrodes exhibit low impedance and high charge injection, essential attributes for flexible and efficient neural interfaces.

Researchers at the Georgia Institute of Technology and China's Tianjin University have created a novel functional semiconductor made from graphene, potentially opening the door to various next-gen electronics. 

This discovery comes at a time when silicon, the material from which nearly all modern electronics are made, is reaching its limit in the face of increasingly faster computing and smaller electronic devices. The semiconductor made from graphene is compatible with conventional microelectronics processing methods – a necessity for any viable alternative to silicon.

Researchers at the University of Bologna have introduced and considered a single layer of brucite Mg(OH)₂, a 2D material that can be easily produced by exfoliation (like graphene from graphite), for the creation of van der Waals composites (known as heterostructures, or heterojunctions), where two monolayers of different materials are stacked and held together by dispersive interactions. 

First principles simulations showed that brucite/graphene composites can modify the electronic properties (position of the Dirac cone with respect to the Fermi level and band gap) according to the crystallographic stacking and the presence of point defects. This could be meaningful for various applications, such as electronics. 

Researchers at North Carolina State University and Pacific Northwest National Laboratory have found that graphene can enhance an important property of metals called the temperature coefficient of resistance. 

They showed that mixing graphene in just the right proportion with copper could lead to improved electrical wires for more efficient electricity distribution to homes and businesses, as well as more efficient motors to power electric vehicles and industrial equipment. The team has applied for a patent for the work, which was supported by the Department of Energy (DOE) Advanced Materials and Manufacturing Technologies Office.

Researchers at the University of Kansas’ Ultrafast Laser Lab have observed the ballistic movement of electrons in graphene in real time. 

Image credit: University of Kansas

“Generally, electron movement is interrupted by collisions with other particles in solids,” said lead author Ryan Scott, a doctoral student in KU’s Department of Physics & Astronomy. “This is similar to someone running in a ballroom full of dancers. These collisions are rather frequent — about 10 to 100 billion times per second. They slow down the electrons, cause energy loss and generate unwanted heat. Without collisions, an electron would move uninterrupted within a solid, similar to cars on a freeway or ballistic missiles through air. We refer to this as ‘ballistic transport.’”

Researchers from Helmholtz-Zentrum Dresden-Rossendorf, Universität Duisburg-Essen, CENTERA Laboratories, Indian Institute of Technology, University of Maryland and the U.S. Naval Research Laboratory have used graphene disks to demonstrate light-induced transient magnetic fields from a plasmonic circular current with extremely high efficiency. 

The effective magnetic field at the plasmon resonance frequency of the graphene disks (3.5 THz) is evidenced by a strong ( ~ 1°) ultrafast Faraday rotation ( ~ 20 ps). In accordance with reference measurements and simulations, the team estimated the strength of the induced magnetic field to be on the order of 0.7 T under a moderate pump fluence of about 440 nJ cm⁻².

Researchers at the National University of Singapore (NUS), University of Science and Technology of China and the National Institute for Materials Science in Japan have developed a way to induce and directly quantify spin splitting in two-dimensional materials.

Using this concept, they have experimentally achieved large tunability and a high degree of spin-polarization in graphene. This research achievement can potentially advance the field of two-dimensional (2D) spintronics, with applications for low-power electronics.

Researchers at Texas A&M University recently discovered that when charging a supercapacitor, it stores energy and responds by stretching and expanding. This insight could be help design new materials for flexible electronics or other devices that need to be both strong and store energy efficiently.

The team measured stresses that developed in graphene-based supercapacitor electrodes and correlated the stresses to how ions move in and out of the material. For example, when a capacitor is cycled, each electrode stores and releases ions that can cause it to swell and contract. According to the team, this repeated motion can cause the build-up of mechanical stresses, resulting in device failure. To combat this, the research looks to create an instrument that measures mechanical stresses and strains in energy storage materials as they charge and discharge.

Researchers at MIT, Harvard and Japan's National Institute for Materials Science have reported a surprising property in graphene: When stacked in five layers, in a rhombohedral pattern, graphene displays a rare, “multiferroic” state, in which the material exhibits both unconventional magnetism and an exotic type of electronic behavior, which the team has named "ferro-valleytricity".

“Graphene is a fascinating material,” said Long Ju, assistant professor of physics at MIT. “Every layer you add gives you essentially a new material. And now this is the first time we see ferro-valleytricity, and unconventional magnetism, in five layers of graphene. But we don’t see this property in one, two, three, or four layers”. The discovery could promote ultra-low-power, high-capacity data storage devices for classical and quantum computers.

Versarien has reported that its Spanish business has secured funding for a new project, in a boost to the group’s turnaround strategy. The Company said its majority-owned subsidiary, Gnanomat, has been awarded a grant of around €415,000 (around USD$445,660) by a government body.

Gnanomat will use the money to help develop and commercialize a new line of conductive inks based on Versarien's nanomaterials, for use in the production of electronic goods.