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Graphene masks: facing up to coronavirus (COVID-19)

Posted By Graphene Council, Wednesday, May 20, 2020
Since the development and isolation of graphene by researchers at Manchester University in 2004, the “2D miracle material” has been put to use in everything from airplanes to anti-corrosive paints, from batteries to body armour (read our earlier blogs Graphene: a new '2D' world and Advanced materials: game-changing graphene). Unsurprisingly, the wonder material is now being put to work in the global fight against COVID-19.

Graphene has been investigated in various biosensor set-ups, including nucleic acid sequencing devices (see the paper Graphene nanodevices for DNA sequencing published in the journal Nature) and diagnostic devices for the monitoring and treatment of HIV (see Graphene-info). Recently, Korean researchers have developed a graphene-based FET biosensor which can detect the SARS-CoV-2 spike protein (the protein on the surface of the COVID-19 virus) from patients’ swabs in less than a minute (see Graphene-info).

However, one key issue in the fight against COVID-19 is maintaining a supply of high quality protective equipment such as masks, gloves and gowns for medical staff.

Among graphene’s myriad of useful properties is its antimicrobial activity attributed, among other reasons, to graphene’s ability to perturb membranes. Several teams have taken advantage of graphene’s antimicrobial, antistatic and electrically conductive properties to develop face masks which can be re-sterilised and, importantly, reused.

For example, IDEATI have developed a cotton fabric facemask with a coating containing both graphene and other carbon nanomaterials. The coating on the mask has been shown to reduce levels of Staphylococcus aureus bacteria by 99.95% within a 24 hour period. The graphene coating also repels dust and is effective against airborne particles of less than 2.5 microns in diameter. The mask can be washed and reused up to 10 times without losing its antibacterial or antistatic properties. The product has currently only been shown to be effective against bacteria. However, IDEATI are currently evaluating the masks antiviral properties (see Graphene-info).

An innovative approach to PPE
Taking a slightly different approach, LIGC Applications have recently launched a graphene-based respirator mask which claims to compete with gold standard N95 respirator masks. N95 respirator masks are used by medical staff as part of their PPE (personal protective gear) and can block 95% of particles over 0.3 microns. However, the COVID-19 virus is approximately 0.2 microns in diameter and can still be transmitted in tiny water droplets of less than 0.3 microns in size (see Graphene-info).

LIGC Applications’ “Guardian G-Volt” mask is allegedly 99% efficient against particles over 0.3 microns, as well as being 80% efficient against anything smaller. The mask has an electrically embedded graphene filtration system formed from laser-induced graphene, a microporous foam which is conductive and can trap pathogens.

The mask, powered by a portable battery pack which is plugged into the mask via a USB port, works by applying a low level electric charge to the surface to sterilise it and repel particles trapped in its graphene filter. The mask also has an LED light which alerts the user when the mask needs to be replaced. N95 masks must be disposed of once they become damp, however, the Guardian G-Volt can be heated and sterilised in a home docking system, which allows the mask to be safely reused.

Of course, wearing a mask alone will not give absolute protection against pathogens, such as the COVID-19 virus. But these advances illustrate that there are a plethora properties of graphene which can be utilised in different ways to achieve a common goal.

Tags:  Batteries  Graphene  Healthcare  nanodevices  Sensors 

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Defective graphene has high electrocatalytic activity

Posted By Graphene Council, Tuesday, May 12, 2020
Scientists from the Moscow Institute of Physics and Technology, Skoltech, and the Russian Academy of Sciences Joint Institute for High Temperatures have conducted a theoretical study of the effects of defects in graphene on electron transfer at the graphene-solution interface. Their calculations show that defects can increase the charge transfer rate by an order of magnitude. Moreover, by varying the type of defect, it is possible to selectively catalyze the electron transfer to a certain class of reagents in solution. This can be very useful for creating efficient electrochemical sensors and electrocatalysts. The findings were published in Electrochimica Acta.

Carbon is widely used in electrochemistry. A new type of carbon-based electrodes, made of graphene, has great potential for biosensors, photovoltaics, and electrochemical cells. For example, chemically modified graphene can be used as a cheap and effective analogue of platinum or iridium catalysts in fuel cells and metal-air batteries.

The electrochemical characteristics of graphene strongly depend on its chemical structure and electronic properties, which have a significant impact on the kinetics of redox processes. The interest in studying the kinetics of heterogeneous electron transfer on the graphene surface has recently been stimulated by new experimental data showing the possibility of accelerating the transfer at structural defects, such as vacancies, graphene edges, impurity heteroatoms, and oxygen-containing functional groups.

A recent paper co-authored by three Russian scientists presents a theoretical study of the kinetics of electron transfer on the surface of graphene with various defects: single and double vacancies, the Stone-Wales defect, nitrogen impurities, epoxy and hydroxyl groups. All these changes significantly affected the transfer rate constant. The most pronounced effect was associated with a single vacancy: The transfer rate was predicted to grow by an order of magnitude relative to defect-free graphene (fig. 1). This increase should only be observed for redox processes with a standard potential of ?0.2 volts to 0.3 volts -- relative to the standard hydrogen electrode. The calculations also showed that due to the low quantum capacitance of the graphene sheet, the electron transfer kinetics can be controlled by changing the capacitance of the bilayer.

"In our calculations, we tried to establish a relation between the kinetics of heterogeneous electron transfer and the changes in the electronic properties of graphene caused by defects. It turned out that introducing defects into a pristine graphene sheet can lead to an increase in the density of electronic states near the Fermi level and catalyze electron transfer," said Associate Professor Sergey Kislenko of the Department for Physics of High-Temperature Processes, MIPT.

"Also, depending on the kind of defect, it affects the density of electronic states across various energy regions in different ways. This suggests a possibility for implementing selective electrochemical catalysis. We believe that these effects can be useful for electrochemical sensor applications, and the theoretical apparatus that we are developing can be used for targeted chemical design of new materials for electrochemical applications," the scientist added.

Tags:  Graphene  Moscow Institute of Physics and Technology  Sensors  Sergey Kislenko 

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Eavesdropping on single molecules with light by replaying the chatter

Posted By Graphene Council, Wednesday, May 6, 2020
The structure of individual molecules and their properties, such as chirality, are difficult to monitor in real time. It turns out that by temporarily bridging molecules together we can provide a lens into their dynamics.

A study led by Prof. Frank Vollmer at the University of Exeter’s Living Systems Institute has exposed new pathways for investigating biochemical reactions at the nanoscale. Thiol/disulfide exchange at equilibrium has not yet been fully scrutinised at the single-molecule level, in part because this cannot be optically resolved in bulk samples.

Light can, however, circulate around micron-sized glass spheres to form resonances. The trapped light can then repeatedly interact with its surrounding environment. By attaching gold nanoparticles to the sphere, light is enhanced and spatially confined down to the size of viruses and amino acids.

The resulting optoplasmonic coupling allows for the detection of biomolecules that approach the nanoparticles while they attach to the gold, detach, and interact in a variety of ways.

Despite the sensitivity of this technique, there is lacking specificity. Molecules as simple as atomic ions can be detected and certain dynamics can be discerned, yet we cannot necessarily discriminate them.

The breakthroughs reported in Nature Communications ("Optoplasmonic characterisation of reversible disulfide interactions at single thiol sites in the attomolar regime") have proceeded to amend this.

Reaction pathways regulated by disulfide bonds can constrain interactions to single thiol sensing sites on the nanoparticles. The high fidelity of this approach establishes precise probing of the characteristics of molecules undergoing the reaction.

By placing linkers on the gold surface, interactions with thiolated species are isolated for based on their charge and the cycling itself.

Sensor signals have clear patterns related to whether reducing agent is present. If it is, the signal oscillates in a controlled way, while if it is not, the oscillations become stochastic. For each reaction the monomer or dimer state of the leaving group can be resolved.

Surprisingly, the optoplasmonic resonance shifts in frequency and/or changes in linewidth when single molecules interact with it. In many cases this result suggests a plasmon-vibrational coupling that could help identify individual molecules, finally achieving characterisation.

"This excellent work by my PhD student, Serge Vincent, paves the way for many future single-molecule analysis techniques that we have only been dreaming about," Professor Frank Vollmer adds. "It is a crucial step for our project ULTRACHIRAL. ULTRACHIRAL seeks to develop breakthroughs in how we use light to analyse chiral molecules."

Tags:  Frank Vollmer  Graphene  nanoparticles  Sensors  University of Exeter 

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Instantaneous reduction of graphene oxide using electric spark for wearable sensors

Posted By Graphene Council, Monday, May 4, 2020
Wearable electronic devices, worn on clothes or the skin to record body parameters such as heartbeat and pulse rate, are currently in great demand. 2D nanomaterials such as graphene, with their exceptional electrical and mechanical properties, play a key role in fabricating these devices. Graphene oxide (GO) is a scalable and low-cost alternative to pristine graphene. However, GO is an insulator and needs to be reduced to an electrically conducting form called reduced Graphene Oxide (rGO) to make it useful for sensors. 

A group of IISc researchers has now devised a novel method to instantaneously reduce graphene oxide using an electric spark.

This method, outlined in a paper published in ACS Applied Materials and Interfaces, is efficient and cost-effective, which would allow easy industrial scale-up. It is also more environment-friendly compared to existing methods as it does not generate chemical residues. Sensors developed using this method can have applications in gesture control, in biomedical rehabilitation to detect the degree and intensity of body movements, and in the field of robotics. 

Graphene and its derivatives are versatile in their electrical and structural properties, and are therefore the preferred materials used to build flexible sensors. The chemical structure of GO allows it to form ‘printable inks’ with various solvents, and bind to the substrate better. Various reduction techniques, including thermal, UV, laser, and microwave-based methods, are used to modify the chemical structure and form rGO. However, these methods are expensive and time-consuming, often produce toxic by-products, and can also damage the substrate.

To reduce graphene oxide efficiently and quickly, the IISc team used an electrical discharge under ambient conditions, popularly known as an electric spark. Sparking on GO deposited over a porous substrate enables its instantaneous reduction, along with a large drop in electrical resistance.

By varying certain parameters in the spark stream, the team was able to tweak the degree of reduction of graphene oxide, and also make predefined conducting patterns, which offers more flexibility in sensor fabrication. The heat present in the spark is highly localised and does not cause any substrate damage; this was verified using a Scanning Electron Microscope.

When mechanical stress is applied to the rGO-coated fabric, it causes a proportional change in the electrical resistance of the rGO film. This property is essential for it to function efficiently as a flex sensor. The change in electrical resistance was found to be consistent over repeated tests and under different bending angles, says Rajanna Konandur, Honorary Professor at the Department of Instrumentation and Applied Physics, and corresponding author of the paper.

He and his team integrated flex sensors containing these spark-reduced rGO films on commercially available gloves, and tested them using bending and other finger movements. Further research can pave the way for inexpensive, large-scale production of flexible, wearable electronics that use these films.

Tags:  2D materials  Graphene  Graphene Oxide  Indian Institute of Science Bengaluru  Medical  nanomaterials  Rajanna Konandur  Sensors 

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Biotech Startup’s Graphene-based Bandage Can Remotely Monitor Wounds

Posted By Graphene Council, Saturday, May 2, 2020
Chronic or hard-to-heal wounds, those that do not heal after six weeks, place a significant economic burden on health systems around the world, costing around $30 billion annually. They lead to half-a-million amputations per year globally. In the US alone, more than 6.5 million people suffer from such wounds.

The costs and incidence of chronic wounds are increasing due to the growing number of older people, among whom pressure ulcers and leg ulcers are more common, and the increase in people with diabetes, who are more prone to foot ulcers.

Faced with this problem and considering that proper assessment of these wounds is not within the reach of caregivers with the relevant expertise, French scientists have developed a new graphene patch that allows them to be monitored remotely.

“The conductivity of the Graphene electrode varies according to the physicochemical changes in the wound, so we have produced films of this material on a polymer (a plastic) and integrated them into a bandage that can record biological parameters by direct contact with the wound bed,” explains Vincent Bouchiat of Grapheal, a spin-off from France's National Centre for Scientific Research (CNRS), which is based at Néel Institute, in Grenoble, where this technology was developed.

A smart, connected dressing

The graphene dressing is ultra-flexible, adapts easily to any part of the body, and has tiny wireless electronics (with lightweight, fully flexible electrodes) that transfer the data to a mobile application. Then, using a telemedicine software and medical technologies in the cloud, the information can reach the hospital to be monitored and evaluated by a specialist.

Medical and nursing staff can remotely monitor how wounds are healing with this system, receiving alerts on any infection that may arise, which helps to prevent complications.

“This can improve and individualize the treatment of chronic wounds that require long-term care,” says Bouchiat, who emphasizes: “In particular, it provides an early detection of infections, allowing a hospital solution at home.”

Stimulating healing

The incorporation of graphene into skin patches of these types not only does not interfere with wound healing, but in fact can actually promotes it, actively stimulating this process, as demonstrated by the pre-clinical studies that have already been conducted.

The first human trials are about to begin.  This medical device has been classified as class II-b (such as condoms or insulin pens, for example) and requires the European mark of conformity. Its launch is planned for 2023.

The creators of the patch had intended to present it in February, along with other projects of the major European initiative known as the Graphene Flagship, at the Mobile World Congress in Barcelona, which was cancelled to prevent the spread of the coronavirus.

In this context, the researchers point out that this new graphene device will be able to help monitor the chronic wounds of isolated people, such as those who have now been forced into this situation by the COVID-19 pandemic.

Tags:  Biomaterials  Grapheal  Graphene  Healthcare  Sensors  Vincent Bouchiat 

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Twisting 2D materials uncovers their superpowers

Posted By Graphene Council, Saturday, May 2, 2020
Two-dimensional (2D) materials, which consist of a single layer of atoms, have attracted a lot of attention since the isolation of graphene in 2004. They have unique electrical, optical, and mechanical properties, like high conductivity, flexibility and strength, which makes them promising materials for such things as lasers, photovoltaics, sensors and medical applications.

When a sheet of 2D material is placed over another and slightly rotated, the twist can radically change the bilayer material's properties and lead to exotic physical behaviours, such as high temperature superconductivity - exiting for electrical engineering; nonlinear optics - exciting for lasers and data transmission; and structural super-lubricity- a newly discovered mechanical property which researchers are only beginning to understand. The study of these properties has given birth to a new field of research called twistronics, so-called because it's a combination of twist and electronics.

Aalto University's researchers collaborating with international colleagues have now developed a new method for making these twisted layers on scales that are large enough to be useful, for the first time. Their new method for transferring single-atom layers of molybdenum disulfide (MoS2) allows researchers to precisely control the twist angle between layers with up to a square centimetre in area, making it record-breaking in terms of size. Controlling the interlayer twist angle on a large scale is crucial for the future practical applications of twistronics.

'Our demonstrated twist method allows us to tune the properties of stacked multilayer MoS2 structures on larger scales than ever before. The transfer method can also apply to other two-dimensional layered materials', says Dr Luojun Du from Aalto University, one of the lead authors of the work.

A significant advancement for a brand-new field of research

Since twistronics research was introduced only in 2018, basic research is still needed to understand the properties of twisted materials better before they find their ways to practical applications. The Wolf Prize in Physics, one of the most prestigious scientific awards, was awarded to Profs. Rafi Bistritzer, Pablo Jarillo-Herrero, and Allan H. MacDonald this year for their groundbreaking work on twistronics, which indicates the game-changing potential of the emerging field.

Previous research has demonstrated that it is possible to fabricate the required twist angle by transfer method or atomic force microscope tip manipulation techniques in small scales. The sample size has usually been in the order of ten-microns, less than the size of a human hair. Larger few-layer films have also been fabricated, but their interlayer twist angle is random. Now the researchers can grow large films using an epitaxial growth method and water assistant transfer method.

'Since no polymer is needed during the transfer process, the interfaces of our sample are relatively clean. With the control of twist angle and ultra-clean interfaces, we could tune the physical properties, including low-frequency interlayer modes, band structure, and optical and electrical properties', Du says.

'Indeed, the work is of great significance in guiding the future applications of twistronics based on 2D materials', adds Professor Zhipei Sun from Aalto University.

Tags:  2D materials  Aalto University  Electronics  Graphene  photovoltaics  Sensors 

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Perovskite/graphene nanosensor detects nitrogen dioxide with 300% improved sensitivity

Posted By Graphene Council, Thursday, April 30, 2020
The research team, led by Juan Casanova and Eduard Llobet, belonging to the Departamento de Ingeniería Electrónica, Eléctrica y Automática at the URV, worked with two materials. First, they used graphene, which is very hydrophobic—water and moisture-resistant—and quite sensitive in gas detection, but with some limitations: it is not very selective and its sensitivity declines over time.

Moreover, they used perovskites, a crystalline-structure material commonly used in the field of solar cells. However, they quickly deteriorate when they are exposed to the atmosphere. That's the reason why they decided to combine perovskites with a hydrophobic material able to repel water molecules such as graphene, in order to prove they can prevent or slow down their deterioration.

"This graphene and perovskites hybrid resulted in a material that can more sensitively detect these kinds of gas. Perovskite alone eventually deteriorates and we have proved that when we put it on top of graphene, their properties and the sensor response remain stable longer," explains Eduard Llobet.

Carbon nanomaterials sensors, a promising future
Researchers have worked for years looking for alternatives to conventional sensors and the carbon nanomaterials field offers promising results in this area. Besides being tiny and needing very low energy for functioning, these materials have proven to have good responses and quick recovery at room temperature, unlike existing sensors.

"They are portable devices due to their size—they can be even wearable. Work at room temperature is very important because they need very small batteries, an unthinkable feature with other materials," says Llobet.
This research has used graphene with perovskite nanocrystals as a toxic gas sensor for the first time and it has proved this combination is a good alternative to detect these compounds due to its high sensitivity over time.

Thanks to the results of this study (Sensors, "Gas Sensing Properties of Perovskite Decorated Graphene at Room Temperature"), perovskites have become an alternative to metals, metal oxides, polymers and other molecules frequently used to modify the surfaces of carbon nanomaterials such as graphene.

The ITQ research team has worked for years in several lines aimed at the synthesis and application of perovskites in fields such as solar cells and photocatalysts. However, their use as sensors is relatively new. ITQ carried out the size and composition control of nanocrystals to make them highly sensitive to nitrogen dioxide.

“These materials present a high potential to develop new gas sensors, because here we take advantage of a limitation in the field of solar cells: "defects" that in the case of sensors play a significant role in the functioning mechanism. In addition, taking into account all the structural modification possibilities of perovskites, we have the opportunity to find a large family of sensors to detect other gases. Also, it is important to note that perovskites are easy to synthesize and they use abundant elements in nature," explains Pedro Atienzar, CSIC scientist at the Instituto de Tecnología Química.

Tags:  Eduard Llobet  Graphene  Instituto de Tecnología Química  nanomaterials  Pedro Atienzar  Sensors 

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High-quality boron nitride grown at atmospheric pressure

Posted By Graphene Council, Wednesday, April 22, 2020
Graphene Flagship researchers at RWTH Aachen University, Germany and ONERA-CNRS, France, in collaboration with researchers at the Peter Grunberg Institute, Germany, the University of Versailles, France, and Kansas State University, US, have reported a significant step forward in growing monoisotopic hexagonal boron nitride at atmospheric pressure for the production of large and very high-quality crystals.

Hexagonal boron nitride (hBN) is the unsung hero of graphene-based devices. Much progress over the last decade was enabled by the realisation that 'sandwiching' graphene between two hBN crystals can significantly improve the quality and performance of the resulting devices. This finding paved the way to a series of exciting developments, including the discoveries of exotic effects such as magic-angle superconductivity and proof-of-concept demonstrations of sensors with unrivalled sensitivity.

Until now, the most widely used hBN crystals came from the National Institute of Material Science in Tsukuba, Japan. These crystals are grown using a process at high temperatures (over 1500°C) and extremely high pressures (over 40,000 times atmospheric pressure). "The pioneering contribution by the Japanase researchers Taniguchi and Watanabe to graphene research is invaluable", begins Christoph Stampfer from Graphene Flagship Partner RWTH Aachen University, Germany. "They provide hundreds of labs around the world with ultra-pure hBN at no charge. Without their contribution, a lot of what we are doing today would not be possible."

However, this hBN growth method comes with some limitations. Among them is the small crystal size, which is limited to a few 100 µm, and the complexity of the growth process. This is suitable for fundamental research, but beyond this, a method with better scalability is needed. Now Graphene Flagship researchers tested hBN crystals grown with a new methodology that works at atmospheric pressure, developed by a team of researchers led by James Edgar at Kansas State University, US. This new approach shows great promise for more demanding research and production.

"I was very excited when Edgar proposed that we test the quality of his hBN", says Stampfer. "His growth method could be suitable for large-scale production". The method for growing hBN at atmospheric pressure is indeed much simpler and cheaper than previous alternatives and allows for the isotopic concentration to be controlled.

"The hBN crystals we received were the largest I have ever seen, and they were all based either on isotopically pure boron-10 or boron-11" says Jens Sonntag, a graduate student at Graphene Flagship Partner RWTH Aachen University. Sonntag tested the quality of the flakes first using confocal Raman spectroscopy. In addition, Graphene Flagship partners in ONERA-CNRS, France, led by Annick Loiseau, carried out advanced luminescence measurements. Both measurements indicated high isotope purity and high crystal quality.

However, the strongest evidence for the high hBN qualitycame from transport measurements performed on devices containing graphene sandwiched between monoisotopic hBN. They showed equivalent performance to a state-of-the-art device based on hBN from Japan, with better performance in some areas.

"This is a clear indication of the extremely high quality of these hBN crystals," says Stampfer. "This is great news for the whole graphene community, because it shows that it is, in principle, possible to produce high quality hBN on a large scale, bringing us one step closer to real applications based on high-performance graphene electronics and optoelectronics. Furthermore, the possibility of controlling the isotopic concentration of the crystals opens the door to experiments that were not possible before."

Mar García-Hernández, Work Package Leader for Enabling Materials, adds: "Free-standing graphene, being the thinnest material known, exhibits a large surface area and, therefore, is extremely sensitive to its surrounding environment, which, in turn, results in substantial degradation of its exceptional properties. However, there is a clear strategy to avoid these deleterious effects: encapsulating graphene between two protective layers."

García-Hernández continues: "When graphene is encapsulated by hBN, it reveals its intrinsic properties. This makes hBN an essential material to integrate graphene into current technologies and demonstrates the importance of devising new scalable synthetic routes for large-scale hBN production. This work not only provides a new and simpler path to produce high-quality hBN crystals on a large scale, but it also enables the production of monoisotopic material, which further reduces the degradation of graphene when encapsulated by two layers."

Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: "This is a nice example of collaboration between the EU and the US, which we fostered via numerous bilateral workshops. Devising alternative approaches to produce high-quality hBN crystals is crucial to enable us to exploit the ultimate properties of graphene in opto-electronics applications. Furthermore, this work will lead to significant progress in fundamental research."

Tags:  Andrea C. Ferrari  Christoph Stampfer  Graphene  Graphene Flagship  Hexagonal boron nitride  Mar García-Hernández  ONERA-CNRS  optoelectronics  RWTH Aachen University  Sensors 

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Graphene Wearables: Exploring Next-Gen Electronics

Posted By Graphene Council, Wednesday, April 22, 2020
Wearable technology refers to any class of electronic items that can be comfortably worn on the body. This covers an ever-growing range of application and product segments, from health and fitness trackers to immersive infotainment systems. They are governed by many of the same principles and trends as other electronics markets, namely extremely high consumer demand for greater functionality in smaller formats. Developers are consistently tasked with miniaturizing devices without compromising on battery life or performance, which mandates next-generation material solutions like graphene sensors.

Graphene Wearable Electronics

The wearable electronics market continues to experience enormous commercial growth due to the release of coveted commercial goods like smartwatches and virtual reality (VR) headsets, contributing to an estimated compound annual growth rate (CAGR) of 15.5%. Provided the market continues to grow as expected, the global wearable electronics market will be worth over $67 billion by 2024.

Although commercialized wearable electronics are now well-cemented in the consciousness of global consumers, they occupy a novel segment of the market. Medical and military-grade wearables have been used routinely for years, while professional sports have exploited health and wellness trackers integrated into clothing for almost as long. Graphene wearable electronics are expected to bridge the gap between these more sophisticated market segments and consumers, allowing the general public to benefit from advanced functionality wearables in increasingly ergonomic formats.
 
Graphene Wearables: UV-Detection Patch

One interesting graphene wearable prototype is a flexible, transparent substrate that can be directly applied to the wearer’s skin. The patch detects and monitors exposure to ultraviolet (UV) rays and, with advanced internet of things (IoT) connectivity, and can alert the user once they have reached a pre-defined threshold of exposure to sunlight. This could help prevent a range of harmful conditions, from sunburn to melanoma.

Graphene-Based Health & Wellness Sensors

Using the same key technology as the previous application, researchers are increasingly hopeful of integrating graphene-based sensors and substrates into fitness trackers with unprecedented levels of functionality. Currently, commercial devices such as smartwatches often feature rudimentary heart-rate monitors based on infrared (IR) sensors, and movement trackers based on integrated accelerometers.

With superior biocompatibility, graphene sensors could offer more detailed insights into a wide range of health and wellness signals, including hydration, oxygen saturation, continuous blood pressure monitoring and temperature.  Additionally, graphene sensors are being developed for pregnant mothers in the form of a wearable patch, that can monitor and track fetal movements in real time, sending potential indicaitons of a problem to medical professionals.

Graphene Sensor Materials from Grolltex

Grolltex is one of the industry-leading producers of single-layer graphene for sensor applications. We utilise a proprietary chemical vapour deposition (CVD) methodology to produce monolayer materials on substrates of your choosing. We are increasingly servicing researchers and product developers with graphene solutions for sensor and wearable applications and are eager to see how the market progresses in the coming years.

Tags:  chemical vapour deposition  Graphene  Grolltex  nanoelectronics  Sensors 

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Grolltex Joins Fight Against Pandemic

Posted By Graphene Council, Monday, April 20, 2020
As researchers and companies around the world set out to battle the Coronavirus pandemic, many are revisiting graphene as a material with potential for helping to win this fight.

Grolltex Inc., a San Diego area biosensor startup that manufactures graphene has partnered up with Sanford Burnham Prebys Medical Discovery Institute to develop a virus testing platform to help combat COVID-19.

The project involves using hand held reader units and disposable plastic testing chips designed for U.S. points of entry including, hospitals and “point of care” locations.

Jumping on the Project
Founded in 2017, Jeff Draa, co-founder and CEO of Grolltex said, “When we saw the COVID-19 virus detection work come out in the literature, showing sensitive and selective detection with a graphene sensor, we knew we had to jump on this project.”

Earlier this month, a team led by Boston College researchers used a sheet of graphene to track the electronic signals inherent in biological structures, to develop a platform to selectively identify deadly strains of bacteria.

Most interestingly, graphene sensors have been shown for several years to be capable of advanced detection and testing in fields such as genomics, small molecule-protein receptor interactions and advanced allergen sensing as well as virus detection, including Zika.

Graphene–Based Sensor
The new scientific findings also show a robust capability for a graphene-based sensor to detect the COVID-19 virus.

“Productization and roll out of a sensor like this is right in our technology wheelhouse. We’re very thankful for the quick response of the folks at Sanford Burnham with their help on the science and testing. It would take many more months, maybe even years, without them,” Draa said.

The company which spun out of UC San Diego has raised a total of $2.2 million from Tech Coast Angels, UC San Diego’s Triton Technology Fund, among other local investors.

Over the past three years, Grolltex primarily sold raw research materials to labs across the globe and eventually pivoted to servicing biosensors giants including a publicly-traded pharmaceutical company and another pharmaceutical organization based in Japan. Names were not disclosed.

As for the project, the “graphene sensor chip on plastic” platform uses a very small biological sample and can perform up to 4 to 12 viral tests, all at one time. As a result, this information may indicate the presence of having a normal flu symptoms versus serious pathogens, including the novel coronavirus.

In addition, its technology is plumbed with a number of control channels which eliminates time-consuming verification steps and helping to provide answers in minutes.

Can Be Made for Pennies
In terms of cost, using the Grolltex industrial-scale graphene manufacturing platform, sensing chips can be made for pennies and in arrays of about 10,000 per single square foot sheet, 100 sheets at a time, according to the company.

In particular, the sensor employs monolayer graphene, a single atom thick layer material. On top of the graphene, the company places additional proprietary and patented nanotechnology, including a unique sensing capability made of “gold nano-islands.”

As of today, the small startup lacks the bandwidth to roll its virus detection platform out following the completion of the science. Draa said, what lies ahead for the startup is to find a local financial partner to help scale its testing platform.

“We currently have our hands full with several prototyping efforts in place in other areas, ranging from glucose detection in saliva to a wearable blood pressure monitor in a patch configuration. But when the Sanford Burnham folks volunteered the science help on this COVID virus detection platform, we knew we had to jump on it”, said Draa, “We’re still a small start-up so we’re looking for a financial or resource partner to help us get this up to volume and in the right hands. We know we’re in one of the best locations in the U.S. for an effort like this so once we make the partnering connections, the ramp will be fast.”

Tags:  Boston College  Graphene  Groltex  Healthcare  Jeff Draa  Sensors 

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