Graphene-Info: the graphene experts

Researchers at the University of Illinois Urbana-Champaign, the US Department of Energy’s National Energy Technology Laboratory (NETL), Argonne National Laboratory and Monash University have used graphene-like carbon dots made from coal to solve a long-standing problem in 2D electronics: how to grow a high-quality, ultrathin insulating layer on top of a 2D semiconductor. The atomically smooth, bond-free surfaces of 2D materials such as graphene and molybdenum disulfide (MoS₂) give them little for a gate dielectric to attach to, and the alternatives, transferring a pre-made film or seeding with organic molecules or metal oxide particles, bring problems of their own, such as residues, rough films and low thermal stability.

The carbon dots are 1-5 nanometers wide and one atomic layer thick, and are derived from coal. The team assembled them into a closely packed monolayer about 0.4 nanometers thick on the surface of the 2D material, using a Langmuir-Schaefer method in which the dots are spread on water, compressed and transferred. The dots bind to the graphene or MoS₂ through weak van der Waals forces without hybridizing with it, while chemical groups at their edges give atomic layer deposition a place to start growing hafnium oxide (HfO₂). Without the carbon dots, the HfO₂ forms rough, porous islands. With them, it forms a smooth film as thin as about 1.6 nanometers. “[Carbon nanodots] act as a primer coat for growing thin, high-quality dielectrics on 2D materials,” said Qing Cao, a professor at Illinois.

Dana Gas and Levidian have started graphene production in Sharjah, after commissioning the first LOOP 20 unit at the Sharjah Graphene Park. The unit is reportedly running at full capacity, with an annual output above one ton. The start comes months after the two companies signed an MoU in May.

Image credit: Dana Gas

The first phase involved an investment of under US$1 million. Two larger units, LOOP 60 and LOOP 100, are being manufactured in the UK. They are expected to lift annual output above 10 tons by the end of 2026, bringing total capital investment to about US$2.5 million. Dana Gas says investment could grow much larger as production scales, but only with long-term customer commitments and suitable returns.

Graphene Manufacturing Group (GMG) has reported new cycling data for its fast-charging graphene aluminium-ion cells, which it is developing with Rio Tinto under a joint development agreement. The 1.5 Ah cells were built and tested by the Battery Innovation Center of Indiana (BIC) using materials GMG makes at its Brisbane development center.

According to GMG, a cell cycled at 7C showed no performance reduction after 1,000 cycles as of October 7, double the cycle life of its previous update. At 10C, which is a six-minute charge and discharge, a second cell lost 10% of its capacity after 393 cycles. A well-known lithium titanate (LTO) cell tested at 10C fell to 80% of its original capacity within 82 cycles. Energy density at the 10C rate rose 48% to 58 Wh/kg, from 39 Wh/kg in the previous update. GMG also reports an energy efficiency of 94% at these rates, compared with 64% for the LTO cell.

Researchers at the University of Manchester, the Institute of Microelectronics of Barcelona (IMB-CNM, CSIC), the Catalan Institute of Nanoscience and Nanotechnology (ICN2) and Multi Channel Systems (Germany) have used graphene micro-transistor arrays to map how brain tissue is faring during an ischemic stroke. The arrays record the slow, DC-coupled electrical signals of cortical spreading depolarizations, waves of disrupted neuronal activity that add secondary injury after a stroke. The team paired the arrays with optical imaging of cerebral blood flow and oxygenation.

In healthy cortex, these waves are normally accompanied by widening of blood vessels. In ischemic tissue they can trigger the opposite response, which worsens metabolic stress and lesion growth. In two stroke models in mice, the duration and shape of the waves scaled with local blood flow. This let the team distinguish relatively preserved cortex from severely ischemic regions within a single preparation.

The European MINIGRAPH project, funded by the European Innovation Council and coordinated by ICN2, has wrapped up with results on graphene neural probes and a robotic way to implant them. The consortium also included INBRAIN Neuroelectronics, imec, Fraunhofer, Leiden University Medical Center, ETH Zurich, Nanoflex Robotics and Palacký University Olomouc. 

The project used Parkinson's disease as its initial application. The aim was an autonomous system that records neural activity, interprets it and delivers targeted stimulation in response. The team developed cortical and subcortical probes based on INBRAIN's graphene thin-film electrodes, along with implantable electronics that can decode signals from hundreds of neural sites. They integrated both into a prototype that was functionally validated in a translational model.

First Graphene has received an initial purchase order from US-based Flux Footwear, its first production application in athletic footwear. Flux will use the company's PureGRAPH graphene additive in its Graphene XT performance gym shoes and leisure range. The additive goes into high-wear outsole areas, aiming to improve durability, abrasion resistance, tear strength and grip without adding weight.

Flux Footwear Adapt Runner. Image from: prnewswire
 

Flux already sells graphene-enhanced shoes under its Graphene-Pro line. First Graphene says the order sets up a pathway to recurring PureGRAPH supply as Flux increases production volumes. 

UK-based Duo Packaging has developed a graphene-enhanced polyethylene film for flexible packaging, created with the University of Manchester's Graphene Engineering Innovation Center (GEIC) and backed by the Innovation Navigator Programme. The material, branded 2DPE, uses graphene to boost the mechanical performance of polyethylene film, allowing manufacturers to use thinner, more heavily recycled plastic without losing strength or sealing performance.

Zoe Brimelow, Dale Brimelow & Mark Dickie (Image credit: Darren Robinson Photography)

In industrial trials with GEIC and live-shopping retailer QVC, the film increased material strength by up to 35% and let QVC raise the recycled content in its packaging from 45% to 60%. QVC also found the film could be heat-sealed at temperatures 15°C lower than standard film, and cut bag thickness from 30 to 28 microns, a 5% weight reduction. QVC has now switched its UK fulfilment center in Liverpool from standard autobagging film to 2DPE, a move expected to save around 50 tonnes of virgin plastic a year and cut QVC's packaging Extended Producer Responsibility (EPR) fees by about £21,150 (about US$27,900) annually.