A new graphene material called diamene switches from flexible to harder-than-diamond upon impact

Researchers from The City University of New York (CUNY) describe a process for creating diamene: flexible, layered sheets of graphene that temporarily become harder than diamond and impenetrable upon impact. The material is fascinating as it is as flexible and lightweight as foil but becomes stiff and hard enough to stop a bullet on impact. Such a material may be beneficial for applications like wear-resistant protective coatings and ultra-light bullet-proof films.

Graphene to be turned into diamene imagePhoto by Red Orbit

The team worked to theorize and test how two layers of graphene could be made to turn into a diamond-like material upon impact at room temperature. The team also found the moment of conversion resulted in a sudden reduction of electric current, suggesting diamene could have interesting electronic and spintronic properties.

Graphene's internal motion could provide limitless clean energy

Researchers at the University of Arkansas, led by professor Paul Thibado, have found strong evidence that the internal motion of 2D materials could be used as a source of clean, limitless energy. The team has reportedly taken the first steps toward creating a device that can turn this energy into electricity, with the potential for many applications. A patent has recently been applied on this invention, called a Vibration Energy Harvester, or VEH.

The team studied the internal movements of carbon atoms in graphene and observed two distinct features: small Brownian motion and larger, coordinated movements. In these larger movements, the entire ripple buckled, flipping up and down like a thin piece of metal being repeatedly flexed. This pattern of small random motion combined with larger sudden movements is known as Lévy flights. This phenomenon can be observed in a variety of contexts, such as biomedical signals, climate dynamics, and more. Thibado is claimed to be the first to have observed these flights spontaneously occurring in an inorganic atomic-scale system.

Graphene-based structures found to have extremely long spin relaxation lifetime

Researchers from Spain's ICN2 institute have discovered that graphene/TMDC heterostructures can exhibit etremely long spin relaxation lifetime. These structure feature lifetimes that are orders of magnitude larger than anything observed in 2D materials - and in fact these results point to a qualitatively new regime of spin relaxation.

Graphene on TMDC image (ICN2)

Spin relaxation lifetime means that time it takes for the spin of electrons in a spin current to lose their spin (return to the natural random disordered state). A long lifetime is very important for spintronics devices. This new study reveals that the rate at which spins relax in graphene/TMDC systems depends strongly on whether they are pointing in or out of the graphene plane, with out-of-plane spins lasting tens or hundreds of times longer than in-plane spins.

Cambridge University inkjet prints graphene-hBN FETs on textiles

Researchers from Cambridge University have demonstrated how graphene and other related 2D materials (namely hBN) can be directly printed onto textiles to create fully inkjet-printed dielectrically gated field effect transistors (FETs) with solution processed 2D materials.

Cambridge team prints graphene-hbn inks on textiles image

According to the team, these devices are washable, flexible, cheap, safe, comfortable to wear and environmentally-friendly, essential requirements for applications in wearable electronics. The team also demonstrated the first reprogrammable memories, inverters and logic gates with solution processed 2D materials by coupling these FETs together to create integrated circuits, the most fundamental components of a modern-day computer.

Chinese scientists design a flexible graphene-based energy storage membrane

Researchers from Tsinghua University in China have designed a low-cost energy storage device using a TiO2-assisted UV reduction of sandwiched graphene components. The sandwich structure consists of two active layers of reduced graphene oxide hybridized with TiO2, with a graphene oxide separator (rGO-TiO2/rGO/rGO-TiO2). In the device, the separator layer also acts as a reservoir for the electrolyte, which affects ion diffusion—a known problem for layered membrane devices—and affects both the capacity and rate performance.

Graphene flexible supercapacitor membrane process image

The team explained that a step-by-step vacuum filtration process is used to form the membrane structure, and the amount of graphene oxide used in the filtration solutions can be adjusted to precisely tune the thickness of each layer. Irradiation of the dried membrane with UV light then reduces the graphene oxide to rGO with assistance from the TiO2.