Graphene enables ultra-fast optical fibre laser for spectroscopy and medical applications

Graphene Flagship researchers have developed a graphene-based optical fibre laser that emits pulses with durations equivalent to just a few wavelengths of the light used. This is said to be the fastest device ever created, and should be ideal for use in ultrafast spectroscopy, as well as in surgical lasers that avoid heat damage to living tissue.

Time resolution is limited by the length of the laser pulse used. The shorter the pulse, the higher the spectroscopic resolution, with the highest possible resolution defined by the cycle length of the particular light frequency employed. In the visible and near-infrared regimes, in which most ultrafast lasers operate, the ultimate pulse duration is between 2 and 5 femtoseconds. Shorter pulses require shorter wavelengths. Pulses as short as two cycles can be generated from laser cavities using a technique known as passive mode-locking.

Read the full story Posted: Aug 05,2015

Will Stanene become graphene's rival in terms of electrical conductivity?

A collaboration between researchers at Stanford University and four universities in China yielded a material made of a single layer of tin atoms, that could be the world's first material to conduct electricity with 100% efficiency at room temperature. The material, called Stanene, is believed to be a rival to graphene and other two-dimensional materials like phosphorene, silicene or germanene, because it is believed to be so conductive as to allow flow of electricity without any heat loss.

The scientists created the mesh by vaporising tin in a vacuum and allowing the atoms to collect on a supporting surface of bismuth telluride. As a result, a two-dimensional honeycomb structure of tin atoms was made. Alas, the substrate and stanene interacted to disrupt the conditions that would have created the perfect conductor - so the team plans to use larger amounts of tin and an inert substrate to rule out interaction. In fact, not all researchers are even sure that the structure created at Stanford is indeed stanene. Direct measurements of the crystal arrangements only can confirm this but that will call for larger amounts of the material.

Read the full story Posted: Aug 05,2015

Graphene and boron nitride nanotubes combine to create digital switches

Researchers at Michigan Technological University created digital switches by combining graphene and boron nitride nanotubes. The combination of these two materials makes for a workable digital switch, which is the basis for controlling electrons in computers, phones, medical equipment and other electronics. This study is a step forward in making semiconductor-free transistors, bypassing many of the troubles that plague silicon.

 

The main challenge was fusing the materials together, and the scientists addressed it by maximizing their existing chemical structures and exploiting their mismatched features. The team exfoliated graphene and modified the material's surface with tiny pinholes. Then the researchers could grow the nanotubes up and through the pinholes.

Read the full story Posted: Aug 05,2015

Skeleton Technologies enters the truck market with its graphene-based supercapacitor technology

Skeleton Technologies, the manufacturer of graphene-based supercapacitors, has entered the commercial truck fleet market. The company recently launched a graphene-based device that helps truck drivers start their engines after long periods of inactivity or in cold weather.

Launched under brand name SkelStart ESM, the device delivers a powerful surge of energy to a truck’s engine to make sure it will start even after long periods of inactivity or in cold weather. The firm explained that it also eliminates the need for drivers to leave their trucks idling.

Read the full story Posted: Aug 04,2015

Controlled defects improve graphene's properties

Researchers from the National Cheng Kung University in Taiwan designed a new method for tweaking the properties of graphene by introducing defects into it. Precise control over the amount and nature of defects could bring about new applications of graphene in everything from drug delivery or electronics.

The scientists used a technique called electrochemical exfoliation to strip graphene layers from graphite flakes. By varying the voltage they discovered they could change the resulting graphene’s thickness, flake area, and number of defects all of which alter its electrical and mechanical properties.

Read the full story Posted: Aug 02,2015

Manchester University collaborates with Akzo Nobel to develop GO-based anti corrosion paints

Manchester University has teamed up with Amsterdam-based paints and coatings company Akzo Nobel, to investigate graphene oxide-based paints that provide protection against rust and corrosion for large metal structures, such as oil rigs, tankers and bridges.

This collaboration between Akzo Nobel and Manchester University is part of a €1m partnership in corrosion research. Akzo Nobel says graphene oxide could provide an ultra-strong, non-corrosive coating for a wide range of industrial applications. Corrosion in its various forms is estimated to cost the global economy $3 trillion a year. Products to protect against corrosion represent an $18 billion world market.

Read the full story Posted: Aug 02,2015