Graphene-Info: the graphene experts

ICFO researchers, along with teams from CIC Nanogune, IIT and Columbia University, have developed a graphene-based phase modulator capable of tuning the light phase between 0 and 2π in situ.

To this end, the researchers exploited the unique wavelength tunability of graphene plasmons, light coupled to electrons in graphene. In their work, they used ultra-high quality graphene to build a fully functional phase modulator with a device footprint of only 350 nm, which is 30 times than the wavelength of the infrared light used for this experiment.

Researchers from China have turned a sheet of graphene oxide into a material that bends when exposed to moisture, which they used to create a spider-like crawler and claw robot that move in response to changing humidity conditions without the need for any external power.

The researchers stated that "Our very simple method for making typical graphene oxides smart is also extremely efficient. A sheet can be prepared within one second". They also reported that graphene oxide sheets treated with brief exposure to bright light in the form of a camera flash exhibited reversible bending at angles from zero to 85 degrees in response to switching the relative humidity between 33 and 86 percent. They also demonstrated that their method is repeatable and the simple robots they created have good stability.

ORA, Canada-based developer of graphene-enhanced audio equipment, recently unveiled its graphene oxide-based composite material, dubbed grapheneQ. A few days ago, the company launched a Kickstarter crowd-funding campaign for graphene-enhanced wireless Bluetooth earphones that promise comfort, high fidelity and long battery life, which has since been doing extremely well and (at the time of writing this post) has already tripled its mark!

The product is regarded as the first commercial audio product to use graphene, and is now available at the "early bird" price of $199 (retail price should be $499). The ORA Headphones feature GrapheneQ membranes for excellent tonality and superior dampening, high efficiency drivers for extended battery life, touchpad controls to skip songs, control volume and answer calls, high quality built-in microphone for hands-free calling, and ear-shaped design optimized for fit and ergonomics.

Researchers at the Indian Institute of Science Education and Research (IISER) Pune have used graphene oxide to develop a novel cancer drug delivery system. The researchers' achievement relies on a rather surprising revelation - they found that when a FDA-approved anticancer drug cisplatin was added, the graphene oxide sheets self-assembled into spherical nanoparticles enclosing the drug within.

Lab tests showed that the nanoparticles (of 90-120 nanometre in size) containing cisplatin and either of two other anticancer drugs ( proflavine and doxorubicin) were taken up by cervical cancer cells leading to programmed cell death.

Researchers at Zhejiang University in China have designed a graphene-based aerogel mimicking the structure of the "powdery alligator-flag" plant that could have potential for use in applications like flexible electronics.

The team drew inspiration from the stem structure of the powdery alligator-flag plant (Thalia dealbata), a strong, lean plant capable of withstanding harsh winds. The researchers used a bidirectional freezing technique that they previously developed to assemble a new type of biomimetic graphene aerogel that had an architecture like that of the plant's stem. When tested, the material supported 6,000 times its own weight and maintained its strength after intensive compression trials and was resilient. They also put the aerogel in a circuit with a LED and found it could potentially work as a component of a flexible device.

Researchers at the Argonne National Laboratory and Oregon State University in the U.S have designed a novel cathode architecture for lithium-sulphide batteries that consists of crystalline di-lithium sulphide nanoparticles encapsulated in few-layer graphene. The design is said to allow the maximum amount of active sulphur species to be incorporated into the electrode and so greatly improves its electrical conductivity. It also overcomes many of the major challenges associated with existing sulphur electrodes and di-lithium composites.

The Li₂S-graphene nanocapsules architecture can boast superior electrochemical properties. The electrodes have a high reversible capacity of 1160 mAh/g and area capacity of 8.1 mAh/cm2. The team synthesized the Li₂S@graphene nanocomposites in a one-step reaction in which they reacted lithium metal foils with CS₂ vapour carried by argon gas at 650°C. Li₂S nanocrystals and the tight wrapper of few-layer graphene are spontaneously generated, thus forming the nanocapsules. The Li₂ nanoparticles are between 50 and 80 nm in size and are uniformly and seamlessly encapsulated in about 10–20 graphene layers. This significantly reduces the charge-transfer resistance between the two materials and greatly improves the electric conductivity of Li2.

Researchers at Rice University and China's Tianjin University have used 3D laser printing to fabricate centimeter-sized graphene objects. The team has demonstrated the making of graphene foams from non-graphene starting materials, in a method that could reportedly be scaled for additive manufacturing applications with pore-size control. The process is conducted at room temperature, without the need for molds. The rather unusual starting materials are powdered sugar and nickel powder.

3D laser printers work differently than the more familiar extrusion-based 3D printers, which create objects by squeezing melted plastic through a needle as they trace out two-dimensional patterns. In 3D laser sintering, a laser shines down onto a flat bed of powder. Wherever the laser touches powder, it melts or sinters the powder into a solid form. The laser is rastered, or moved back and forth, line by line to create a single two-dimensional slice of a larger object. Then a new layer of powder is laid over the top of that layer and the process is repeated to build up three-dimensional objects from successive two-dimensional layers.