New graphene-based metasurface capable of independent amplitude and phase control of light

A KAIST research team in collaboration with the University of Wisconsin-Madison theoretically developed a graphene-based active metasurface capable of independent amplitude and phase control of mid-infrared light. This research gives a new insight into modulating the mid-infrared wavefront with high resolution by solving the problem of the independent control of light amplitude and phase, which has remained a long-standing challenge.

Light modulation technology is essential for developing future optical devices such as holography, high-resolution imaging, and optical communication systems. Liquid crystals and a microelectromechanical system (MEMS) have previously been utilized to modulate light. However, both methods suffer from significantly limited driving speeds and unit pixel sizes larger than the diffraction limit, which consequently prevent their integration into photonic systems.

Tuning the interlayer spacing of graphene laminate films yields extremely efficient supercapacitors

Scientists from University College London and the Chinese Academy of Sciences have proposed a graphene-based design for supercapacitors, which reportedly increased their density by 10 times.

Supercapacitors charge quickly but also discharge at a high speed. Existing supercapacitors tend to have a low energy density – about 1/20 of the battery capacity. Batteries combined with supercapacitors are already in limited use – for example, in Chinese public transport. But the bus in which such a battery is installed is forced to charge at almost every stop.

Researchers determine if graphene promotes or prevents the corrosion of copper

Scientists from Chung-Ang University, Korea, led by Prof Hyungbin SonKorea, have observed a unique way in which graphene forms a hybrid layer that prevents copper corrosion.

Does graphene cause or prevent the corrosion of copper? New study finally settles the debate image

A challenge with using copper is that its surface oxidizes over time, even under ambient conditions, ultimately leading to its corrosion. Thus, finding a long-term method to protect the exposed surfaces of copper is a valuable goal. One common way of protecting metal surfaces is by coating them with anti-corrosive substances. Graphene is studied extensively as a candidate for anti-corrosive coating, as it serves as a barrier to gas molecules. But, despite these properties, graphene sheets have been said to protect copper from corrosion only over short periods (less than 24 hours). In fact, surprisingly, after this initial period, graphene appears to possibly increase the rate of copper corrosion, which is completely in contrast to its anti-corrosive nature.

New method produces graphene on surfaces for precise electronics applications

Scientists at Rice University, the University of Tennessee, Knoxville (UT Knoxville) and Oak Ridge National Laboratory (ORNL) have demonstrated the use of a very small visible beam to burn graphene into microscopic patterns.

Schematic of the method for finely creating graphene with a small laser imageScientists recorded the formation of laser-induced graphene made with a small laser mounted to a scanning electron microscope. Image credit: the Tour Group

The labs of Rice chemist James Tour, which discovered the original method to turn a common polymer into graphene in 2014, and Tennessee/ORNL materials scientist Philip Rack revealed they can now watch the conductive material form as it makes small traces of LIG in a scanning electron microscope (SEM).

New graphene-based material to increase recording density of data storage devices

An international group of Russian and Japanese scientists recently developed a graphene-based material that might significantly increase the recording density in data storage devices, such as SSDs and flash drives. Among the main advantages of the material is the absence of rewrite limit, which will allow implementing new devices for Big Data processes.

The development of compact and reliable memory devices is an increasing need. Today, traditional devices are devices in which information is transferred through electric current. The simplest example is a flash card or SSD. At the same time, users inevitably encounter problems: the file may not be recorded correctly, the computer may stop "seeing" the flash drive, and to record a large amount of information, rather massive devices are required.

Versarien - Think you know graphene? Think again! Versarien - Think you know graphene? Think again!