A scientist has discovered a previously unknown three-dimensional nanostructure consisting of graphene sheets. Graphene is a single monolayer of carbon atoms forming a hexagonal two-dimensional crystal lattice. The discovered nanostructure is a multilayer system of parallel hollow channels with quadrangular cross-section extending along the surface. The discovered nanostructure looked so extraordinary that it took some time to understand what it actually was. The structure was dramatically different from whatever had previously been observed on graphite.
Adding to the options for wirelessly powering implants from outside the body, researchers are proposing a light-driven powering device using near infrared rays (nIR). Flashing light impulses, which are absorbed by the device, induce temperature fluctuation, thus generating voltage/current pulses which can be used for charging a battery or biological stimulations. This flexible and compact device can generate electrical pulses with controllable amplitude and width when remotely irradiated by nIR. Not only can it supply power to implantable bioelectronics, but it also provides adjustable electrical pulses for nerve stimulation.
The complexity of the microenvironment of a biological cell is influenced by many factors, including surface topography and chemistry; matrix stiffness; mechanical stress; molecular liquid composition and other physiochemical parameters. However, most artificial biointerfaces are developed based on just a single chemical or physical factor to direct cell behaviors. The functions performed by these artificial biointerfaces are far simpler than those performed in the natural cell microenvironment. In an effort to more closely mimic a cell's natural environment, researchers have fabricated an antibody modified reduced graphene oxide platform and used it to significantly improve the efficiency for capturing circulating tumor cells.
Given the huge economic incentives, corrosion prevention and protection is a major business. The advanced materials that are being developed and used in modern industries require increasingly sophisticated coatings for improved performance and durability. Take for example the case of microbially induced corrosion (MIC) - one of the lesser understood forms of corrosion where micro-organisms manifest metallic surfaces and induce substantial damage that often goes unnoticed until there is a loss in the component functionality. New research features graphene as a promising novel surface coating that can be used to minimize metallic corrosion under harsh microbial conditions.
A carbon material with high electrical conductivity, high specific surface area, tunable pore structure, mechanically robust framework, and high chemical stability is an important requirement for advanced electrochemical energy storage. However, neither porous carbon or sp2 carbon can full meet these requirements yet. How to create a conductive carbon material with especially large pore volume, and hence large surface area, has therefore been a key focus in electrode research.
Synthesis of holey two-dimensional (2D) nanosheets with defined hole morphology and hole edge structures remains a great challenge for graphene. It is also an issue for other 2D nanomaterials, such as hexagonal boron nitride (h-BN) and molybdenum disulfide. In new work, researchers have reported a facile, controllable, and scalable method to carve geometrically defined pit/hole shapes and edges on h-BN basal plane surfaces via oxidative etching in air using silver nanoparticles as catalysts.
With increasing sensitivity, electrical, mechanical and optical sensors are able to detect low molecular weight chemical and biological analytes under ever more dilute conditions. At the same time, though, researchers want to keep the sensing process as simple as possible without complex functionalization and complicated preparation steps for the in situ detection. A novel graphene-gold metasurface-based biosensing architectures makes extreme phase singularities possible due to a strong field enhancement on the graphene-gold interface.
The noise level in devices with graphene and other two-dimensional (2D) materials has to be reduced in order to enable their practical applications. It will not be possible to build graphene-based communication systems or detectors until the noise spectral density is decreased to the level comparable with the conventional state-of-the-art transistors.Researchers have now demonstrated that the electronic noise in graphene devices can be strongly suppressed if a graphene channel is encased between two layers of hexagonal boron nitride.