Nanowerk March 22, 2023 Current tissue engineering approaches combine different scaffold materials with living cells to provide biological substitutes that can repair and eventually improve tissue functions. Both natural and synthetic materials have been fabricated for transplantation of stem cells and their specific differentiation into muscles, bones, and cartilages. One of the key objectives for bone regeneration therapy to be successful is to direct stem cells’ proliferation and to accelerate their differentiation in a controlled manner using growth factors and osteogenic inducers. An international team of researchers (Singapore, South Korea) has shown that graphene provides a promising biocompatible scaffold that […]
Category Archives: Graphene
Reaching superconductivity layer by layer
Phys.org March 2, 2023 Multilayered graphene has many promising qualities ranging from widely tunable band structure and special optical properties to new forms of superconductivity. An international team of researchers (Austria, Israel) studied multilayer graphene for the possibility of creating topological superconductivity. In their theoretical model, simulated on a computer, they looked at various possible arrangements of different graphene sheets on top of each other and the behavior of electrons that move in the multiplayer graphene. Depending on how the different layers of graphene are shifted with respect to each other and on how many layers there were, the positively […]
Study: Superconductivity switches on and off in ‘magic-angle’ graphene
Pays.org January 30, 2023 Superconducting FETs operate through continuous tuning of carrier density, but no bistable superconducting FET, which could serve as a new type of cryogenic memory element, has been reported. Recently, gate hysteresis and resultant bistability in Bernal-stacked bilayer graphene aligned to its insulating hexagonal boron nitride gate dielectrics were discovered. An international team of researchers (USA- MIT, Israel) reported the observation of hysteresis in magic-angle twisted bilayer graphene (MATBG) with aligned boron nitride layers. The bistable behaviour coexists alongside the strongly correlated electron system of MATBG without disrupting its correlated insulator or superconducting states. The all-van der […]
At the edge of graphene-based electronics
Nanowerk December 22, 2022 An international team of researchers (USA – Georgia Institute of Technology, National High Magnetic Field Laboratory, France) has demonstrated that the annealed edges in conventionally patterned graphene epitaxially grown on a silicon carbide substrate (epigraphene) are stabilized by the substrate and support a protected edge state. The edge state has a mean free path that is greater than 50 microns, 5000 times greater than the bulk states and involves a theoretically unexpected Majorana-like zero-energy non-degenerate quasiparticle that does not produce a Hall voltage. In seamless integrated structures, the edge state formed a zero-energy one-dimensional ballistic network […]
Simpler graphene method paves way for new era of nanoelectronics
Phys.org March 15, 2022 The high electron mobility of graphene points to great potential for broadband communications and high-speed electronics operating at terahertz switching rates. However, complex, and expensive fabrication methods make it more expensive and hinder mass production of such devices. Researchers in Sweden proposed chemical vapor deposition (CVD) of graphene on commercial copper (Cu) foils providing a scalable route towards high-quality single-layer graphene. The graphene is grown on a metallic surface like Cu, Pt or Ir, after which it can be separated from the metal and transferred to specifically required substrates. The process can be simply explained as […]
Achilles heel of graphene exposed
Nanowerk July 19, 2021 The quantum Hall effect is the seminal example of topological protection as charge carriers are transmitted through one-dimensional edge channels where backscattering is prohibited. In conventional Hall bar geometries, topological protection of graphene edge channels is found less robust than in high mobility semi-conductors. An international team of researchers (Belgium, Germany, Japan) exploring graphene quantum Hall regime at the local scale revealed that the detrimental influence of antidots along the graphene edges, mediating backscattering towards upstream edge channels triggering topological breakdown. The finding is a major step forward in the understanding of the quantum Hall effect […]
Physicists find misaligned carbon sheets yield unparalleled properties
Science Daily July 31, 2020 In an earlier study an international team of researchers (Yale University, UT Dallas, Japan) showed that when offset by 0.93 degrees, twisted bilayer graphene exhibits both superconducting and insulating states, thereby widening the magic angle significantly. In the current research they set out to determine how mid-infrared light might affect the conductance of electrons in twisted bilayer graphene. Their work involved calculating the light absorption based on the moiré pattern’s band structure. They showed that the theoretical results not only matched well with the experimental findings, but also pointed to a mechanism that is fundamentally […]
Nanotube ‘rebar’ makes graphene twice as tough
Science Daily August 4, 2018 In 2014 Rice University researchers developed Rebar graphene that consists of CNTs embedded in graphene. An international team of researchers (USA – Rice University, University of Maine, Brown University, China) implemented a “dry” transfer technique to test the freely suspended rebar graphene under uniaxial tension mode. Combined experiments and molecular dynamics simulations confirmed that the embedded CNTs divert and bridge the propagating crack and provide a toughening mechanism for the material. This is a promising extrinsic toughening strategy for 2D materials and provides mechanistic insights into the fracture process of graphene hybrid material. The experiments […]