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Nanotechnology Spotlight

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Showing Spotlights 9 - 16 of 142 in category Graphene and Other 2D Materials (newest first):

 

Record high sensitive graphene Hall sensors

graphene_sensorMagnetic field sensors are in very high demand for precise measurements of position, proximity and motion. The most commonly used Hall Effect devices are fabricated with silicon. The sensitivities of these sensors - voltage and current - depend on the device materials electronic properties such as charge carrier mobility and density. However, for futuristic advanced applications higher sensitivity Hall sensors are required than can be achieved with silicon. Researchers now have set a new world record for the sensitivity of Hall sensors using highest quality graphene encapsulated in hexagonal boron nitride.

Posted: May 21st, 2015

Improving the energy storage in graphene with defects

graphene_defectsCounter intuitive to our idea of 'perfection equals best performance', researchers have shown that defects in nanocarbons could provide a breakthrough for increasing the quantum capacitance. By subjecting graphene layers to a reactive-ion etching process, the team has poked holes into graphene to create holey graphene, which can change the microscopic distribution of electrons and thereby increase the quantum capacitance of graphene by at least fourfold.

Posted: May 5th, 2015

3D-printed graphene for electronic and biomedical applications

3D-printed_grapheneFrom a 3D printing perspective, graphene has been previously incorporated into 3D printed materials, but most of these constructs comprise no greater than about 20 volume % of the total solid of the composite, resulting in electrical properties that are significantly less than what has been achieced in new work. Here, researchers show that high volume fraction graphene composite constructs can be formed from an easily extrudable liquid ink into multi-centimeter scaled objects.

Posted: Apr 28th, 2015

A nanotechnology sensor for one-step detection of Bishpenol A

graphene_biosensorWhile the actual toxicity of Bisphenol A (BPA) is still debated, the direct measurement of BPA is difficult because of the weak response given by conventional electrochemical sensors, and current optical analysis methods are susceptible to the influence of interfering substances. A novel aptamer/graphene oxide FRET biosensor now provides a method for the rapid detection and risk assessment of BPA with high sensitivity and selectivity.

Posted: Apr 13th, 2015

Chemically enhanced 2D material makes excellent tunable nanoscale light source

microdisk_light_emissionMolybdenum disulfide's (MoS2) semiconducting ability, strong light-matter interaction and similarity to the carbon-based graphene makes it of interest to scientists as a viable alternative to graphene in the manufacture of electronics, particularly photoelectronics. In particular, MoS2 has excellent optical properties when deposited as a single, atom-thick layer - unlike graphene, it emits light when excited; albeit relatively poorly. In order to realize the potential of atomically thin MoS2 as a nanoscale active material in a light source, a considerable enhancement of its emission efficiency is necessary.

Posted: Mar 12th, 2015

A thermionic energy converter using single-layer graphene

graphene_cathodeHeat energy can be converted into electricity with very high efficiency through a temperature-induced electron flow process known as thermionic emission. Thermionic energy converters have been used with different heat sources, all of them requiring operation at high temperatures above 1500 K. A new study indicates that heat temperature can be lowered by an order of magnitude if using graphene as hot cathode. The findings indicate that a graphene-based cathode thermionic converter operating at 900 K could reach an efficiency of 45%.

Posted: Mar 5th, 2015

Printing graphene folds

folded_grapheneIn an effort to find a way to introduce folds or waves into graphene in a simple and large-scale way, researchers have invented a rubber-stamp printing method to introduce waves into the graphene. The ability to controllably form folds in graphene has significant research and technological applications. Induced folds have a sublithographic width and macroscopic length. They could be used as channel materials or interconnects in chips, and it has been shown that stable field emitters are formed by folded graphene.

Posted: Feb 16th, 2015

3D-printing with graphene

graphene_structureThe successful implementation of graphene-based devices invariably requires the precise patterning of graphene sheets at both the micrometer and nanometer scale. It appears that 3D-printing techniques are an attractive fabrication route towards three-dimensional graphene structures. Researchers have now used flakes of chemically modified graphene, namely graphene oxide GO and its reduced form rGO, together with very small amounts of a responsive polymer, to formulate water based ink or pastes to be used in 3D printers..

Posted: Feb 9th, 2015