Electronics - Page 24

Scientists at The National Physical Laboratory's (NPL) have been investigating the hydrophobicity of epitaxial graphene, which could be used in the future to better tailor graphene coatings to applications in medicine, electronics and more. Contrary to popular beliefs, the scientists' findings indicate that graphene's hydrophobicity is strongly thickness-related, with single-layer graphene being significantly more hydrophilic than its multi-layered graphene.

As graphene-based devices will have to operate in ambient conditions with existing (and unmonitored) humidity, it may be troublesome that such conditions can affect graphene's performance through changes in its mechanical and electrical properties; The new study, conducted in collaboration with the Naval Research Laboratory, addresses the question of whether graphene is hydrophobic or hydrophilic. The common assumption is that graphene is hydrophobic, but it seems that the results of this study prove the question more complex than previously thought.

A PhD student at the University of Manchester has won a prestigious award accompanied by a £50,000 grant. The prize money will be used to help found a new graphene start-up company based on producing graphene inks. 

A collaborative Innovate UK project called Project Graphted that began on 1st April 2015 aims at evaluating Graphene’s potential as a transparent electrode when dispersed in a polymeric matrix. Graphted will be led by PolyPhotonix, a UK-based company that develops applications based on OLED lighting panels, and will include a 12 month feasibility study in which PolyPhotonix will be working in collaboration with Applied Graphene Materials and CPI (a UK-based R&D institute that helps companies develop and scale manufacturing processes).

The project seeks to provide proof of concept evidence that a Graphene-based electronic device can be successfully developed and fully categorised in terms of morphology and physical properties. If so, the approach holds potential to generate a range of electronic inks that can be utilised on a large scale. Application areas include OLEDs and organic photovoltaics (OPV).

A team of scientists from Pohang University of Science and Technology (POSTECH) managed to tune black phosphorus' band gap to form a superior conductor, allowing for the application to be mass produced for electronic and optoelectronics devices.

The tunable band gap in BP effectively modifies the semiconducting material into a unique state of matter with anisotropic dispersion. This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.

Researchers at the University of Wisconsin-Madison have discovered a way of growing graphene nanoribbons with desirable semiconducting properties directly on a conventional germanium semiconductor wafer. This finding may allow manufacturers to easily use graphene nanoribbons in hybrid integrated circuits, which promise to deliver a major boost to the performance of next-gen electronic devices. This technology could also have specific uses in industrial and military applications, such as sensors that detect specific chemical and biological species and photonic devices that manipulate light.

The technique for producing graphene nanoribbons is said to be scalable and compatible with the prevailing infrastructure used in semiconductor processing - nanoribbons that can be grown directly on the surface of a semiconductor like germanium are more compatible with planar processing used in the semiconductor industry, and so would pose less of a barrier to integrating these materials into electronics in the future.

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.

Researchers at Rice University developed a theoretical model that shows how a 3D lattice of boron nitride (also known as "white graphene" as it shares many similar qualities with it, but is not made of carbon atoms) could be deployed as a tunable material to control heat flow in electronic devices. Cooling measures that prevent overheating in electronics are important for developing and sustaining advanced electronic components.

Its 3D structure allows the speculated boron nitride system to conduct heat in any direction as opposed to most circuits, in which heat moves in one direction. The multiple heat directing properties of boron nitride provide excellent opportunities to ‘cool’ down electronic devices. This can be controlled further by building pillars of boron nitride of differing shapes and thickness.

Researchers at Chalmers University of Technology in Sweden demonstrated how graphene films can be used for the efficient cooling of electronic devices. Disposing of excess heat in efficient ways is imperative to prolonging electronic lifespan, and would also lead to a considerable reduction in energy usage.

In 2013, Chalmers researchers had observed the impact of graphene in having a cooling effect on silicon-based technology. This earlier technique, however, was filled with problems since it consisted of only of a few layers of thermal conductive atoms and could not be used to rid electronic devices of great amounts of heat. Researchers tried to resolve this issue by stacking additional layers of graphene to augment its effect, but it ended up revealing yet another issue - as extra layers are added, it significantly lessens the ability of graphene to remain adhered to the electronic device.

Researchers at VIT University, India demonstrated the application of conjugated polymer/Graphene oxide nanocomposite for thermistor applications. The study resulted in a thermistor that boasted excellent performance, suitable for electronics and sensors. A thermistor is a type of resistor whose resistance is dependent on temperature, more so than in standard resistors.

Interestingly, the study showed that lower amounts of graphene oxide (0.5, 1%) loading exhibited positive temperature coefficient, and higher loading (1.5, 2%) yielded negative temperature coefficient.

Researchers from the University of Exeter have designed a new method to produce graphene significantly cheaper and easier than previously production methods. The researchers claim that this high-quality, low cost graphene could pave the way for the development of the first truly flexible 'electronic skin', that could be used in robots.

The new method grows graphene in an industrial cold wall CVD system, a state-of-the-art piece of equipment recently developed by UK graphene company Moorfield. This nanoCVD system is based on a concept already used for other manufacturing purposes in the semiconductor industry. This new technique is said to grow graphene 100 times faster than conventional methods, reduce costs by 99% and have enhanced electronic quality. The research team used this new technique to create the first transparent and flexible touch-sensor that could enable the development of artificial skin for use in robot manufacturing as well as flexible electronics.