Graphene sensors: introduction and market status - Page 28

Graphenea, in collaboration with industrial and academic partners (Infineon Technologies, WITec, RWTH Aachen University and Simune Atomistics), announced the successful completion of project NanoGraM that focused on nano/microelectromechanical (NEMS/MEMS) devices based on graphene. The project focused on three specific device concepts for potential future products: graphene microphones, graphene-membrane pressure sensors and graphene-membrane Hall sensors.

The target markets for these devices include portable electronics (smartphones, laptops), automotive, industrial, and smart homes, among others.

Versarien, the advanced materials engineering group, has announced that it has entered into a collaboration agreement with AXIA Materials to develop graphene-enhanced composite materials and smart graphene devices using both Versarien's proprietary Nanene graphene nano platelets and proprietary Graphinks graphene inks.

AXIA, based in South Korea, develops advanced thermoplastic composite material solutions under its LiteTex brand for the automotive, sports, electronics and building sectors, and produces pre-fabricated buildings under its Pixel Haus brand.

Researchers at the University of Texas at Austin and Seoul National University have successfully developed and tested an ultrathin artificial retina, based on graphene and molybdenum disulfide, that could reportedly improve on existing implantable visualization technology for the blind. The flexible device could someday restore sight to the millions of people with retinal diseases. And with a few modifications, the device could be used to track heart and brain activity.

"This is the first demonstration that you can use few-layer graphene and molybdenum disulfide to successfully fabricate an artificial retina," Nanshu Lu, Ph.D., says. "Although this research is still in its infancy, it is a very exciting starting point for the use of these materials to restore vision," she says, adding that this device could also be implanted elsewhere in the body to monitor heart and brain activities.

Partners of the European Project 'Graphene Flagship' at the University of Strasbourg and CNRS (France), along with an international team of collaborators, created new 'switches' that respond to light. The team combined light-sensitive molecules with layers of graphene and other 2D materials to create new devices that could be used in sensors, optoelectronics and flexible devices.

The researchers designed a molecule that can reversibly undergo chemical transformations when illuminated with ultraviolet and visible light. This molecule (a photoswitchable spiropyran) can be then attached to the surface of materials like graphene or molybdenum disulfide, thus generating an atomically precise hybrid macroscopic superlattice. When illuminated, the whole supramolecular structure experiences a collective structural rearrangement, which could be directly visualized with a sub-nanometer resolution by scanning tunneling microscopy.

Archer Exploration, in collaboration with The University of Adelaide, has developed graphene-based conductive inks derived from Archer’s Campoona graphite deposit. The inks produced were used to print electronic circuits with an inkjet printer, later using a laser-scribed printer for the preparation of basic electrode patterns.

Centimetre-sized printed graphene electronics (electrodes) on plastic (polyethylene terephthalate) using graphene inks derived from Archer’s Campoona graphite

The graphene inks were reportedly prepared using a combination of established methods and proprietary methods that took advantage of the superior physical and chemical properties of Archer’s Campoona graphite. The rheological properties of inks are yet to be tested and optimized, and are the subject of the ongoing collaboration. The Company stated that the results of the work will be used to secure intellectual property rights to commercially viable technology integrating printed graphene componentry for biosensing devices.

A team of researchers from Denmark, Italy and Portugal recently discovered a new mechanism for controlling electronic devices using molecules. The researchers have shown that the ferroelectric ordering of polar molecules attached to the edge of graphene can be toggle-switched by an electrostatic gate and can be used for memory devices and sensors.

Molecular electronics aims to use individual molecules to control electronics. The large library of molecules and techniques to modify them can create more sophisticated electronics than previously thought possible. The normal hindrance is the small size of the molecules. It's possible to create them, but they are incredibly difficult to handle. It is almost impossible to manipulate small enough features in ordinary materials to electrically connect with individual molecules.

Computers based on fluids instead of silicon is not a new concept, and now researchers at the National Institute of Standards and Technology (NIST) have shown how computational logic operations could be performed in a liquid medium by simulating the trapping of ions (charged atoms) in graphene floating in saline solution. The scheme might also be used in applications such as water filtration, energy storage or sensor technology.

NIST's ion-based transistor and logic operations are simpler in concept than earlier proposals. The new simulations show that a special film immersed in liquid can act like a solid silicon-based semiconductor. For example, the material can act like a transistor, the switch that carries out digital logic operations in a computer. The film can be switched on and off by tuning voltage levels like those induced by salt concentrations in biological systems.

Engineers from the UCLA have Used graphene to design a new type of photodetector that can work with more types of light than its current state-of-the-art counterparts. The device also has superior sensing and imaging capabilities.

photodetectors' versatility and usefulness depend largely on three factors: their operating speed, their sensitivity to lower levels of light, and how much of the spectrum they can sense. Typically, when engineers have improved a photodetector’s capabilities in any one of those areas, at least one of the two other capabilities has been diminished. The photodetector designed by the UCLA team has major improvements in all three areas it operates across a broad range of light, processes images more quickly and is more sensitive to low levels of light than current technology.

A collaboration between two innovative material technology startups Graphmatech and Add North 3D (a Swedish 3D materials developer specialized in FDM materials) has developed novel conductive Aros Graphene-based filaments for 3D printing. This may open up many new different 3D-printing applications such as thermal management components, circuit boards and efficient electromagnetic and radio frequency shielding.

The recently developed 3D-printing technology based on Graphematech's Aros Graphene may grant the ability to control the exact level of conductivity of the filament. The new filaments will now be optimized and go through beta testing with a reference group before it is expected to reach the market in 6-12 month.

Australia-based advanced materials company Talga Resources has reported high levels of electrical conductivity in concrete by using an additive developed from the Company’s graphene-graphite research and development laboratory in the UK.

(L) Talga concrete sample after melting 5cm depth of ice from 9v power. (R) Conceptual underfloor heating/road application.

The reported breakthrough offers substantial potential in existing and emerging industrial applications, particularly as concrete is the world’s largest construction material by volume. Talga shared information gathered from tests that show that the graphene-enhanced concrete is highly electrically conductive - attaining 0.05 ohm.cm volume resistivity.