Technical / Research

Researchers from MIT, Princeton University, SLAC National Accelerator Laboratory and Japan's National Institute for Materials Science have created a new ultrathin 2D material with unusual magnetic properties that initially surprised the researchers before they went on to solve the complicated puzzle behind those properties’ emergence. As a result, the work introduces a new platform for studying how materials behave at the most fundamental level — the world of quantum physics.

The scientists, led by MIT's Pablo Jarillo-Herrero, worked with three layers of graphene. Each layer was twisted on top of the next at the same angle, creating a helical structure reminiscent of a DNA helix.

Researchers from the University of British Columbia, the University of Washington, Johns Hopkins University and Japan's National Institute for Materials Science have identified a new class of quantum states in a custom-engineered graphene structure. Their new study reports the discovery of topological electronic crystals in twisted bilayer–trilayer graphene, a system created by introducing a precise rotational twist between stacked two-dimensional materials.

“The starting point for this work is two flakes of graphene, which are made up of carbon atoms arranged in a honeycomb structure. The way electrons hop between the carbon atoms determines the electrical properties of the graphene, which ends up being superficially similar to more common conductors like copper,” said Prof. Joshua Folk, a member of UBC’s Physics and Astronomy Department and the Blusson Quantum Matter Institute (UBC Blusson QMI).

Researchers from Penn State recently developed a portable and wireless device to simultaneously detect SARS-CoV-2, the virus that causes COVID-19, and vitamin C, a critical nutrient that helps bolster infection resistance, by integrating commercial transistors with printed laser-induced graphene.  

By simultaneously detecting the virus and vitamin C levels, the test could help individuals and their health care providers decide on more effective treatment options, the researchers said. For example, someone with low vitamin C levels may benefit from a supplemental boost, while someone with normal or high vitamin C levels may need to consider other options.  

Researchers from Canada's University of Ottawa, Iridian Spectral Technologies and University of Bayreuth in Germany have developed combined methods to enhance THz nonlinearities in graphene-based structures. The team's innovative methods aim to enhance frequency conversion of terahertz (THz) waves in graphene-based structures, unlocking new potential for faster, more efficient technologies in wireless communication and signal processing.

Schematic of the experimental configuration at the sample position to generate and detect THz third harmonic generation. Image from:  Light: Science & Applications 

THz waves, located in the far-infrared region of the electromagnetic spectrum, can be used to perform non-invasive imaging through opaque materials for security and quality control applications. Additionally, these waves hold promise for wireless communication. Advances in THz nonlinear optics, which can be used to change the frequency of electromagnetic waves, are essential for the development of high-speed wireless communication and signal processing systems for 6G technologies and beyond.

Researchers from Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST), Pohang University of Science and Technology, Institute for Basic Science, KAIST, Japan's National Institute for Materials Science and Max Planck Institute for Solid State Research in Germany have observed a unique quantum state in twisted bi-layer graphene.

This research provides insights into a quantum state that challenges the limitations of conventional semiconductor technology, broadening the horizon for quantum advancements and offering new avenues for technological innovation.

Würzburg University researchers have created a defect in graphene that allows ions to pass through, which could lead to new applications in water filtration or sensor technology.

The Würzburg model system consisting of two nanographene layers that can absorb and bind chloride ions (green) through a defect in the crystal lattice. (Image: Kazutaka Shoyama / Universität Würzburg)

Defects that allow scientists to control the permeability of graphene for different substances can be very useful: ‘So-called defects can be created in the carbon lattice of graphene. These can be thought of as small holes that make the lattice permeable to gases,’ says chemistry professor Frank Würthner from Julius-Maximilians-Universität (JMU) Würzburg in Germany.

The Advanced Carbons Company (TACC), a wholly owned subsidiary of HEG, has entered into a Non-Binding Memorandum of Understanding (MOU) with Ceylon Graphene Technologies (CGT) with regard to advancing graphene technology and unlocking its vast potential for diverse applications.

CGT, a LOLC company based in Sri Lanka, is a global expert in graphene production. Leveraging Sri Lanka's premium vein graphite, renowned for its purity and backed by its expertise in material science, CGT aims to be at the forefront of delivering innovative and high-quality graphene products. TACC, part of the LNJ Bhilwara Group, is known for its expertise in synthetic graphite and commitment to sustainable, green technologies. 

Researchers from Korea's DGIST, Kyungpook National University, France's University of Bordeaux (CNRS), Collège de France and Japan's Komaba Institute for Science (KIS) recently designed a solar-powered faradaic supercapacitor, with a graphene layer as its anode, that can reportedly achieve a power density of 2,555.6 W kg and an energy efficiency of 63%. The system uses nickel-based compounds to enhance the electrochemical performance of its electrodes.

Schematic of the system. Image from: PV Magazine, credit: Daegu Gyeongbuk Institute of Science and Technology (DGIST)

To build these electrodes, the scientists used a nickel-based carbonate and hydroxide composite material, which are said to optimize their conductivity and stability. They initially tested transition metal ions such as manganese (Mn), carbon monoxide (Co), copper (Cu), iron (Fe), and zinc (Zn) and found that the optimal nanostructure of the electrodes depended on the transition metals used.

Researchers from Seoul National University of Science and Technology, Korea Advanced Institute of Science and Technology and Korea Institute of Machinery and Materials recently reported a graphene-based laser lift-off technique that prevents damage while separating ultrathin OLED displays. This advancement could open the door towards ultra-thin, stretchable devices that fit comfortably against human skin, revolutionizing wearable device technology.

a) Graphene-enabled laser lift-off (GLLO) process. b) Conventional laser lift-off (LLO) process. Image from: Nature Communications

Polyimide (PI) films are widely used in these applications due to their excellent thermal stability and mechanical flexibility. They are crucial for emerging technologies like rollable displays, wearable sensors, and implantable photonic devices. However, when the thickness of these films is reduced below 5 μm, traditional laser lift-off (LLO) techniques often fail. Mechanical deformation, wrinkling, and leftover residues frequently compromise the quality and functionality of ultrathin devices, making the process inefficient and costly.

Researchers from China's Zhejiang University have developed a new thermal management system to prevent thermal runaway of Li-ion battery (LIB) cells, using hyperbolic graphene phase change composites. This addresses the safety concerns of LIB cells, mainly caused by thermal runaway. While phase change material systems already exist, the unresolved trade-off between high power and energy density greatly limits its practical applications. 

The newly developed thermal management system relies on a composite material that consists of hyperbolic graphene framework and paraffin, and reportedly exhibits an impressive thermal conductivity of ∼30.75 W/mK at 12.5 wt% graphene loading and ultrahigh retention (90%) of latent heat, beyond that of most of the reported phase change composites.