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A 3D camera for safer autonomy and advanced biomedical imaging

Posted By Graphene Council, Thursday, February 6, 2020
Researchers at the University of Michigan have proven the viability of a 3D camera that can provide high quality three-dimensional imaging while determining how far away objects are from the lens. This information is critical for 3D biological imaging, robotics, and autonomous driving.

Instead of using opaque photodetectors traditionally used in cameras, the proposed camera uses a stack of transparent photodetectors made from graphene to simultaneously capture and focus in on objects that are different distances from the camera lens.

The system works because of the unique traits of graphene, which is only one atomic layer thick and absorbs only about 2.3% of the light. A pair of graphene layers can be used to construct a photodetector that can efficiently detect light, even though less than 5% of the light is absorbed. When placed on a transparent substrate, instead of a silicon chip for example, the detectors can be stacked, with each one in a different focal plane.

As described by Prof. Ted Norris: “When you have a camera, you have to have a focusing adjustment on your lens so that when you’re focusing on a particular object like a person’s face, the rays of light that are coming from that person’s face are focused onto that single plane on your detector chip. Items in front or behind the object are out of focus.

But if it were possible to stack different detector arrays each in different focal planes, then they could each image accurately a different place in the object space simultaneously. What’s more, if you can detect multiple focal planes of data all at the same time, you can use algorithms to reconstruct the object in three dimensions. That is called a light field image. We have demonstrated how to use transparent focal stacks to do light field image and image reconstruction.”

In addition to basic object identification, the current paper shows how their device can detect how far away something is – making it suitable for applications in autonomous driving and robotics. It is also ideal for biological imaging in cases where it is important to image three-dimensional volume.

For its ultimate success, the project required complementary expertise in three areas. Prof. Zhaohui Zhong’s team developed the graphene devices; Norris’ group worked on the design features of the optical instrument and demonstrated the devices in the lab; and Prof. Jeff Fessler’s group, which developed the image reconstruction algorithm.

Fessler echoed the other faculty in stating the group of nine researchers consisting of faculty, postdocs and students “coalesced as a great team, all learning from each other and contributing different aspects of the final paper.”

Inspiration for the camera came from previous research of Zhong and Norris on highly sensitive graphene photo detectors, published in Nature Nanotechnology in 2014.

The current transparent graphene sensors fabricated so far are too low-resolution to depict images, but the initial experiments showed that the lens focused light from a different distance on each of the two sensors. Work is continuing on the project.

Tags:  biological imaging  Graphene  Medical  Robotics  Sensors  Ted Norris  University of Michigan 

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New graphene amplifier has been able to unlock hidden frequencies in the electromagnetic spectrum

Posted By Graphene Council, Thursday, February 6, 2020
Researchers have created a unique device which will unlock the elusive terahertz wavelengths and make revolutionary new technologies possible.

Terahertz waves (THz) sit between microwaves and infrared in the light frequency spectrum, but due to their low-energy scientists have been unable to harness their potential. The conundrum is known in scientific circles as the terahertz gap.

Being able to detect and amplify THz waves (T-rays) would open up a new era of medical, communications, satellite, cosmological and other technologies.

One of the biggest applications would be as a safe, non-destructive alternative to X-rays. However, until now, the wavelengths – which range between 3mm and 30μm – have proved impossible to utilise due to relatively weak signals from all existing sources.

A team of physicists has created a new type of optical transistor – a working THz amplifier – using graphene and a high-temperature superconductor.

The physics behind the simple amplifier replies on the properties of graphene, which is transparent and is not sensitive to light and whose electrons have no mass. It is made up of two layers of graphene and a superconductor, which trap the graphene massless electrons between them, like a sandwich.

The device is then connected to a power source. When the THz radiation hits the graphene outer layer, the trapped particles inside attach themselves to the outgoing waves giving them more power and energy than they arrived with – amplifying them.

Professor Fedor Kusmartsev, of Loughborough’s Department of Physics, said: “The device has a very simple structure, consisting of two layers of graphene and superconductor, forming a sandwich. “As the THz light falls on the sandwich it is reflected, like a mirror. “The main point is that there will be more light reflected than fell on the device.

“It works because external energy is supplied by a battery or by light that hits the surface from other higher frequencies in the electromagnetic spectrum.

“The THz photons are transformed by the graphene into massless electrons, which, in turn, are transformed back into reflected, energised, THz photons.

“Due to such a transformation the THz photons take energy from the graphene – or from the battery – and the weak THz signals are amplified.”

The breakthrough – made by researchers from Loughborough University, in the UK; the Center for Theoretical Physics of Complex Systems, in Korea; the Micro/Nano Fabrication Laboratory Microsystem and THz Research Center, in China and the AV Rzhanov Institute of Semiconductor Physics, in Russia – has been published in Physical Review Letters, in the journal, American Physical Society (APS).

The team is continuing to develop the device and hopes to have prototypes ready for testing soon. Prof Kusmartsev said they hope to have a working amplifier ready for commercialisation in about a year. He added that such a device would vastly improve current technology and allow scientists to reveal more about the human brain.

“The Universe is full of terahertz radiation and signals, in fact, all biological organisms both absorb and emit it. “I expect, that with such an amplifier available we will be able to discover many mysteries of nature, for example, how chemical reactions and biological processes are going on or how our brain operates and how we think.

“The terahertz range is the last frequency of radiation to be adopted by humankind. “Microwaves, infrared, visible, X-rays and other bandwidths are vital for countless scientific and technological advancements.

“It has properties which would greatly improve vast areas of science such as imaging, spectroscopy, tomography, medical diagnosis, health monitoring, environmental control and chemical and biological identification.

“The device we have developed will allow scientists and engineers to harness the illusive bandwidth and create the next generation of medical equipment, detection hardware and wireless communication technology.”

Tags:  amplifier  Fedor Kusmartsev  Graphene  Healthcare  Loughborough University  Medical 

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New production method for carbon nanotubes gets green light

Posted By Graphene Council, Thursday, January 9, 2020
A new method of producing carbon nanotubes - tiny molecules with incredible physical properties used in touchscreen displays, 5G networks and flexible electronics - has been given the green light by researchers, meaning work in this crucial field can continue.

Single-walled carbon nanotubes are among the most attractive nanomaterials for a wide range of applications ranging from nanoelectronics to medical sensors. They can be imagined as the result of rolling a single graphene sheet into a tube.

Their properties vary widely with their diameter, what chemists call chirality - how symmetrical they are - and by how the graphene sheet is rolled.

The problem faced by researchers is that it is no longer possible to make high quality research samples of single-walled carbon nanotubes using the standard method. This was associated with the Carbon Center at Rice University, which used the high-pressure carbon monoxide (HiPco) gas-phase process developed by Nobel Laureate, the late Rick Smalley.

The demise of the Carbon Center in the mid-2010s, the divesting of the remaining HiPco samples to a third-party entity with no definite plans of further production, and the expiration of the core patents for the HiPco process, meant that this existing source of nanotubes was no longer an option.

Now however, a collaboration between scientists at Swansea University (Wales, UK), Rice University (USA), Lamar University (USA), and NoPo Nanotechnologies (India) has demonstrated that the latter's process and material design is a suitable replacement for the the Rice method.

Analysis of the Rice "standard" and new commercial-scale samples show that back-to-back comparisons are possible between prior research and future applications, with the newer HiPco nanotubes from NoPo Nanotechnologies comparing very favourably to the older ones from Rice.

These findings will go some way to reassure researchers who might have been concerned that their work could not continue as high-quality nanotubes would no longer be readily available.

Professor Andrew Barron of Swansea University's Energy Safety Research Institute, the project lead, said:
"Variability in carbon nanotube sources is known to be a significant issue when trying to compare research results from various groups. What is worse is that being able to correlate high quality literature results with scaled processes is still difficult".

Erstwhile members of the Smalley group at Rice University, which developed the original HiPco process, helped start NoPo Nanotechnologies with the aim of updating the HiPco process, and produce what they call NoPo HiPCO® SWCNTs.

Lead author Dr. Varun Shenoy Gangoli stated:
"It is in the interest of all researchers to understand how the presently available product compares to historically available Rice materials that have been the subject of a great range of academic studies, and also to those searching for a commercial replacement to continue research and development in this field."

Tags:  Andrew Barron  carbon nanotubes  Graphene  Medical  nanoelectronics  Rice University  Sensors  Swansea University  Varun Shenoy Gangoli 

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Graphene activates immune cells helping bone regeneration in mice

Posted By Graphene Council, Thursday, November 28, 2019
Graphene has been used for many years in the aeronautics and automotive industries and is even used to create new composites. However, it still has a long way to go to offer the consumer the revolutionary applications promised since Andre Geim and Konstantin Novoselov received the Nobel Prize in Physics in 2010. A team of researchers from several Italian universities within the Graphene Flagship Consortium intends to change this and apply it to regenerative medicine therapies.

Publications about the biomedical applications of graphene-based materials have increased in recent years. So says the researcher from Graphene Flagship partner University of Padua (Italy) Lucia Gemma Delogu, who considers that this is due to its "incredible" physicochemical properties, a long list that ranges from its high flexibility and resistance to its good conductivity, both electrical and thermal.

Delogu and her team have worked to take advantage of the material in the field of biomedicine. Their study, published this year in Nanoscale, shows how the immune properties of graphene allow bone tissue to regenerate in mice. This is possible through nano-tools that can activate or deactivate the immune response, an approach that is of great interest for cancer therapies and tissue engineering.

"Graphene-based materials can improve bone regeneration, a complex process that requires interaction between immune and skeletal cells," Delogu explains to Sinc. In the study, the researchers combined a type of graphene oxide with calcium phosphate, a substance capable of activating this regeneration.

"The injection of the graphene-based material into the tibia of mice showed an improvement in the bone mass in the area and in bone formation, suggesting that the combination is capable of activating monocytes to induce osteogenesis," continues the researcher.

How does the body respond to graphene?

Delogu is also the coordinator of the G-Immunomics project, whose objective is to analyse the impact of graphene on the health of living beings, with a view to its possible biomedical applications. G-Immunomics is one of the Partnering Projects of the Graphene Flagship, a European consortium of more than 150 research centres and companies, with a budget of 1,000 million euros and the goal of taking graphene and related materials towards application.

"The use of graphene in biomedicine may revolutionize medical protocols with new theranostic approaches," a concept that merges the terms "therapy" and "diagnosis" in the context of personalized medicine. "If we learn how graphene interacts with our immune system, we will be able to explore much more specific therapies for the treatment of diseases," she says.

The researcher explains that these interactions are complex, so it is still "an image that lacks several colours." By injecting a material, it comes into contact with the immune cells in the blood, which means that studying the impact of graphene on the immune response is "fundamental".

For this reason, Delogu's team is also studying how graphene can stimulate or suppress the immune response. "Our research wants to show a broad picture of the interaction of immune cells in blood with layered materials such as those based on graphene," with the ultimate goal of their possible to apply in biomedicine efficiently but also safely.

Graphene against osteoporosis
Diseases related to bone loss, such as osteoporosis, are a problem for millions of people worldwide. The World Health Organisation estimates that, in Europe alone, 22 million women and 5.5 million men aged 50-84 suffer from osteoporosis.

"Our preclinical research reveals that functionalized graphene may offer a medical opportunity to fight these bone-related diseases," says Delogu. "By promoting bone regeneration, they could also be used to improve the healing of bone wounds and shorten their duration."

Even, she says, "to combat bone loss suffered by astronauts due to lack of gravity". In this área, Delogu is involved in the project WHISKIES recently funded by the European Space Agency.

For all these reasons, she is confident that graphene can a have a future in biomedicine "We are at an early stage, but we hope that the work will open the door to real clinical applications for graphene-based materials," she says. Her dream is to explore the immunological potential of graphene in other fields of regenerative medicine.

Tags:  Andre Geim  Graphene  Healthcare  Konstantin Novoselov  Lucia Gemma Delogu  Medical  University of Padua 

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New graphene-based material developed for medical implants

Posted By Graphene Council, Thursday, May 2, 2019
Updated: Wednesday, May 1, 2019
A group of scientists have developed a new material for biomedical applications by combining a graphene-based nanomaterial with Hydroxyapatite (HAp), a commonly used bioceramic in implants.

In recent years, biometallic implants have become popular as a means to repair, restructure or replace damaged or diseased parts in orthopaedic and dental procedures. Metal parts also find use in devices such as pacemakers.

However, metallic implants face several limitations and are not a permanent solution. They react with body fluids and corrode, release wear and tear debris resulting in toxins and inflammation. They also have high thermal expansion and low compressive strength causing pain and are dense and may cause reactions.

On the other hand, bioceramics do not have these limitations. HAp specifically is osteoconductive, with a bone-like porous structure offering the required scaffold for tissue re-growth. However, it is brittle and lacks the mechanical strength of metals. The problem is overcome by combining it with nanoparticles of materials such as Zirconia.

In the new research, scientists have combined HAp with graphene nanoplatelets. “Previously reported studies have focused on only structural properties of such composites without throwing light on their biological properties. We have found that combining HAp with graphene nanomaterial enhances mechanical strength, provides better in-vivo imaging and biocompatibility without changing its basic bone-like properties,” explained Dr Gautam Chandkiram, the principal investigator at University of Lucknow, while speaking to India Science Wire.

Purification of the base ceramic material is a significant primary challenge in fabricating composites. According to scientists, in the current study, highly efficient biocompatible Hydroxyapatite was successfully prepared via a microwave irradiation technique and the consequent composites was synthesised using a simple solid-state reaction method.

The process involved mixing different concentrations of graphene nanoplatelet powders and drying, crushing, sieving and ball-milling the resulting slurry. The fine composite powder was further cold-compressed and sintered at 1200 degrees Celsius to achieve the desired density.

The scientists found that the composite had adequate interfacial area between the nanoparticles, with the graphene nanoplatelets well distributed into the hydroxyapatite matrix, while exhibiting high fracture resistance. Further, structural characterization, mechanical and load bearing tests showed that the 2D nature of graphene improves the load transfer efficiency significantly.

Researchers also examined cell viability of the composite by observing metabolic activity in specific cells using a procedure known as MTT assay. They used gut tissues of Drosophila larvae and primary osteoblast cells of a rat. “The overall cell viability studies demonstrated that there is no cytotoxic effect of the composites on any cell type,” explained Dr. Gautam.

Biomaterials also find use in drug delivery and bioimaging diagnosis. “Our research on the composite found that it displays a better fluorescence behaviour as compared to pure hydroxyapatite, indicating it has a great potential in bone engineering and bioimaging bio-imaging applications as well,” he added.

Tags:  2D Materials  Gautam Chandkiram  Graphene  Medical  nanomaterials  University of Lucknow 

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Graphene and 2D Materials on Track to Innovative Applications

Posted By Graphene Council, Wednesday, April 10, 2019
Updated: Wednesday, April 10, 2019

The CORDIS Results Pack showcases 12 articles on 6 ambitious cutting-edge EU research projects funded under the EU’s FP7 and Horizon 2020 research programmes relevant to graphene and 2D materials. Of these, seven articles cover different aspects of the Graphene Flagship. 


The Graphene Flagship is the EU’s biggest research initiative and has a budget of EUR 1 billion, representing a new form of joint, coordinated research initiative on an unprecedented scale. Through a combined academic-industrial consortium, the research effort covers the entire value chain, from materials production to components and system integration, aiming to exploit the unique properties of graphene. 

An introduction to graphene outlines work conducted by the Flagship including collaboration with the European Space Agency over the use of graphene in space applications such as light propulsion and thermal management. Researchers also used optoelectronic communication systems to provide fast data for the future. The large-scale production of graphene for commercial market applications involved scaling up manufacturing to industrial scale whilst maintaining consistency high quality and cost efficiency.

Scientists investigated chemical processing and functional applications of graphene and graphene-related materials for engineering new molecular structures with unique properties. Graphene spintronics utilised both electron charge and spin at room temperature to create new possibilities for information processing and storage. Finally the Flagship has investigated the use of graphene for biomedical applications to develop innovative medical devices and sensors for detecting treating and managing nervous system diseases. 

European graphene research doesn’t all fall under the remit of the Flagship and researchers are using other EU funding mechanisms to undertake other projects. GRAPHEALTH produced the next generation of wearable sensors while GRASP applied interactions between graphene and light to quantum computing and biomedicine. GraTA developed tunneling accelerometers for use in machine vibration monitoring. HIGRAPHEN created dense polymer composites for use in optoelectronics and energy storage. PolyGraph (working closely with the Graphene Flagship) studied graphene-reinforced polymers for use in the aeronautics and automobiles sectors.

Tags:  2D materials  Cordis  Graphene  Medical  The Graphene Flagship 

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Biodegradable Graphene

Posted By Graphene Council, Wednesday, March 27, 2019
Degradation of pristine graphene occurs in the human body when interacting with a naturally occurring enzyme found in the lung, announced Graphene Flagship partners; the French National Centre for Scientific Research (CNRS), University of Strasbourg, Karolinska Institute and University of Castilla–La Mancha (UCLM).

Graphene based products are being designed to be interfaced with the human body within the Graphene Flagship, including flexible biomedical electronic devices.  If graphene is to be used for such biomedical applications, it should be biodegradable and thus be expelled from the body.

To test how graphene behaves within the body, Alberto Bianco and his team at Graphene Flagship partner CNRS, conducted several tests looking at if and how graphene was broken down with the addition of a common human enzyme. The enzyme in question, myeloperoxidase (MPO), is a peroxide enzyme released by neutrophils, cells that are responsible for the elimination of any foreign bodies or bacteria that enter the body, found in the lungs. If a foreign body or bacteria is detected inside of the body, neutrophils surround it and secrete MPO, thereby destroying the threat. Previous work by Graphene Flagship partners found MPO to successfully biodegrade graphene oxide [Small, 20151; Nanoscale, 20182]. However the structure of non-functionalized graphene was thought to be more degradation resistant.  To test this, Bianco and his team looked at the effects of MPO, ex vivo, on two graphene forms; single- and few-layer.

Bianco explains, "We used two forms of graphene, single- and few-layer, prepared by two different methods in water. They were then taken and put in contact with myeloperoxidase in the presence of hydrogen peroxide. This peroxidase was able to degrade and oxidise them. This was not really expected because we thought that non functionalized graphene was more resistant than graphene oxide."

Rajendra Kurapati, first author on the study, from Graphene Flagship partner CNRS, said, "The results emphasize that highly dispersible graphene could be degraded in the body by the action of neutrophils. This would open the new avenue for developing graphene-based materials."

With successful ex-vivo testing, in-vivo testing is the next stage. Bengt Fadeel, Professor at Graphene Flagship partner Karolinska Institute, "Understanding whether graphene is biodegradable or not is important for biomedical and other applications of this material. The fact that cells of the immune system are capable of handling graphene is very promising."

Prof. Maurizio Prato, leader of Work Package 4, dealing with Health and Environment impact studies,  based at Graphene Flagship Partner University of Trieste, said, "The enzymatic degradation of graphene is a very important topic, because in principle, graphene dispersed in the atmosphere could produce some harm. Instead, if there are microorganisms able to degrade graphene and related materials, the persistence of these materials in our environment will be strongly decreased. These types of studies are needed. What is also needed is to investigate the nature of degradation products. Once graphene is digested by enzymes, it could produce harmful derivatives. We need to know the structure of these derivatives and study their impact on health and environment."

Prof. Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship, and chair of its management panel added "The report of a successful avenue for graphene biodegradation is a very important step forward to ensure the safe use of this material in applications. The Graphene Flagship has put the investigation of the health and environment effects of graphene at the centre of its programme since the start. These results strengthen our innovation and technology roadmap"

Tags:  Alberto Bianco  Andrea C. Ferrari  French National Centre for Scientific Research  Graphene  Karolinska Institute  Maurizio Prato  Medical  Rajendra Kurapati  The Graphene Flagship  University of Castilla–La Mancha  University of Strasbourg 

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Graphene enables a test for cancer that is faster, more accurate and less expensive!

Posted By Terrance Barkan, Monday, October 16, 2017

An international team of researchers led by Professor Steven Conlan, Swansea University Medical School and the Centre for NanoHealth has won an international award for a graphene biosensor based diagnostic test for ovarian cancer which is quicker, more accurate, less expensive and portable.

The team developed a testing device which can diagnose ovarian cancer in a few minutes using a drop of blood. This portable technology is different from the ones currently in the hospital environment and allows for greater flexibility in terms of monitoring a patient even after she has already been diagnosed with ovarian cancer.

As well as the test being simple and fast the test does not require a technically-developed laboratory or a specialized technician to operate it which reduces costs and means that there isn’t a need for a centralisation of services. The device can also be used with other biomarkers to detect other types of disease.

Ovarian cancer research award ‌Professor Conlan, together with colleagues Dr Sofia Teixeira (Swansea University College of Engineering), Drs Lewis Francis, Deya Gonzalez and Lavinia Margarit (from the Swansea University Medical School), and Dr Ines Pinto from the International Iberian Nanotechnology Laboratory, INL, Braga, Portugal have been recognised for their pioneering work with the award of the i3S Hovine Capital Health Innovation prize.
 
Professor Conlan said: “The Hovione prize will allow the team to initiate the process of moving our device from the lab to the patient. Whilst there is much work to be done, this is an important step towards the better and earlier diagnosis of patients with ovarian cancer. Cooperation between the two European centres has been key in realising this achievement.”

i3S Hovine Capital Health Innovation prize, created this year, aims at distinguishing innovative ideas in the area of health. The winners of the grand prize receive €35,000 in financing and services that include a market study, development of a business plan, technology validation by industrial experts, and support in setting up a company based on the winning technology.

The i3S-Hovione Capital Health Innovation Prize is supported internationally by the European Institute of Innovation and Technology (EIT-Health) and has partnerships with several entities, such as Bluecinical (PT), Patentree (PT), SRS Advogados (PT), Impact Science (UK), and ANI / MCTES (PT) through its Bfk Award.

Tags:  Biosensor  Cancer  Graphene  Healthcare  Medical 

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