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Atom-thick sheets unlock future technologies
A new way of splitting layered materials to give atom thin "nanosheets" has been discovered. This has led to a range of novel two-dimensional nanomaterials with chemical and electronic properties that have the potential to enable new electronic and energy storage technologies. The collaborative* international research led by the Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Ireland, and the University of Oxford has been published in this week's Science.

The scientists have invented a versatile method for creating these atom thin nanosheets from a range of materials using common solvents and ultrasound, utilising devices similar to those used to clean jewellery. The new method is simple, fast, and inexpensive, and could be scaled up to work on an industrial scale.

"Of the many possible applications of these new nanosheets, perhaps the most important are as thermoelectric materials. These materials, when fabricated into devices, can generate electricity from waste heat. For example, in gas-fired power plants approximately 50% of energy produced is lost as waste heat while for coal and oil plants the figure is up to 70%. However, the development of efficient thermoelectric devices would allow some of this waste heat to be recycled cheaply and easily, something that has been beyond us, up until now," explained Professor Jonathan Coleman, Principal Investigator at CRANN and the School of Physics, Trinity College Dublin who led the research along with Dr Valeria Nicolosi in the Department of Materials at the University of Oxford.

This research can be compared to the work regarding the two-dimensional material graphene, which won the Nobel Prize in 2010. Graphene has generated significant interest because when separated into individual flakes, it has exceptional electronic and mechanical properties that are very different to those of its parent crystal, graphite. However, graphite is just one of hundreds of layered materials, some of which may enable powerful new technologies.

Coleman's work will open up over 150 similarly exotic layered materials – such as Boron Nitride, Molybdenum disulfide, and Bismuth telluride – that have the potential to be metallic, semiconducting or insulating, depending on their chemical composition and how their atoms are arranged. This new family of materials opens a whole range of new "super" materials.

For decades researchers have tried to create nanosheets from layered materials in order to unlock their unusual electronic and thermoelectric properties. However, previous methods were time consuming, laborious or of very low yield and so unsuited to most applications.

"Our new method offers low-costs, a very high yield and a very large throughput: within a couple of hours, and with just 1 mg of material, billions and billions of one-atom-thick nanosheets can be made at the same time from a wide variety of exotic layered materials," explained Dr Nicolosi, from the University of Oxford.

These new materials are also suited for use in next generation batteries – "supercapacitors" – which can deliver energy thousands of times faster than standard batteries, enabling new applications such as electric cars. Many of these new atomic layered materials are very strong and can be added to plastics to produce super-strong composites. These will be useful in a range of industries from simple structural plastics to aeronautics.



The joints are among the first parts of the body to suffer the inevitable ravages of aging, the cartilage can break during sports or to wear down over the years due to usage. Currently, scientists are experimenting with a combination of stem cells and novel structural materials designed to mimic real tissue, hoping to disappear for the pain that accompanies this problem and perhaps prevent the emergence of achieving arthritis.

In animal models, these transplants appear to stimulate the regeneration of cartilage that is more like natural tissue.

The cartilage damage often leads to osteoarthritis, a degenerative joint disease that affects about half of the population aged 65 years. Existing treatments for these small problems usually require cartilage inflict further damage to the diseased joint, or cartilage cells transplant, called chondrocytes, obtained from a healthy joint, developed in form of culture and injected into the damaged area. Both procedures enabled the development of new tissue, a cartilage-like version of a scar, more fibrous than normal cartilage and that usually does not have the same durability.

In an attempt to actually regenerate cartilage rather than patch it, Rocky Tuan, director of the Cartilage Biology and Orthopedics Branch of the National Institute of Arthritis and Musculoskeletal and Skin Diseases, Baltimore, and colleagues developed a nanofiber structure similar structurally to extracellular matrix, a fibrous material that provides support to the body’s connective tissue. The structure generated by electrospinning, a process imported textiles. The researchers applied a strong electric field to a liquid polymer, which is elongated fibers in an attempt to dissipate the load.

The nanoscale structure of the material is the key experiments have indicated that cells grow better in a nanoscale fiber structure in a millimeter scale made of the same metral.

The structures are created from mesenchymal stem cells (adult stem cells derived from bone marrow, fatty tissue or other sources and can differentiate between muscle, bone, fat and cartilage). “The advantage is that it is not necessary for damage other tissue cells,” says Tuan.

The use of nanotechnology in medicine is a burgeoning field. Some developments of the new science are already being used, and many others are undergoing development and testing. One current use is nanotechnology drug delivery. Put simply, nanotechnology drug delivery involves using nanoparticles, microscopic manmade compounds, to deliver medicine, light, heat or other treatments to a particular organ or tissue in the body. Delivering medication only to the specific cells or tissue that needs it — a tumor, for example — is thought to be more effective as well as safer than conventional treatments.

Nanotechnology drug delivery to fight cancer is one of the key treatments being explored by researchers, and testing on nanotechnology that specifically targets tumor cells has already begun. The nanoparticles are designed so that they are attracted to the diseased cells only and not to any other tissue in the patient's body. With older medication-delivery technologies, the chemotherapy used to treat cancer can harm healthy tissue or fail to reach the targeted cancer cells.

Researchers are also exploring ways to use nanotechnology to allow patients to receive a dose of medicine orally instead of by injection. Again, nanoparticles are used to deliver the medicine to where it is needed. In this case, the important aspect of the nanotechnology drug delivery is that it helps the medication pass through the patient's stomach without breaking down. Once in the patient's intestines, the medicine can then pass into the bloodstream.

Of course, nanomedicine is not being explored exclusively for drug delivery. Scientists and medical researchers are also considering ways to use nanotechnology as the medicine or therapy itself. For instance, doctors have created nanoparticles called buckyballs, which are designed to help an allergy sufferer in the middle of a reaction. Nanofibers, which are microscopic filaments that could be used to repair a patient's damaged cartilage, are also being tested.

Two other possible uses for nanomedicine include diagnostic imaging and destroying germs. Certain nanoparticles have already proved themselves capable of killing staph infections and other microbes. As for imaging, certain nanoparticles might be able to help doctors discover tumors that are difficult to detect or to help lab workers uncover disease indicators in a blood or tissue sample.


Medical nanotechnology is a branch of nanotechnology which applies principles in this field to health care issues. Nanotechnology is a broad spectrum of scientific endeavors which involves manufacturing and machining which take place on a molecular scale. There are a number of potential applications for medical nanotechnology, and in its early phases, many people were quite excited about the huge changes which could occur in the medical world with the assistance of medical technology.

Because nanotechnology operates on such a small scale, it offers the opportunity to create precisely targeted surgical instruments, drug delivery systems, and implants. Nanobots, for example, could be used to perform a non-invasive medical imaging study inside the body, or to perform surgical procedures. Nanomaterials can also be implanted into the body; for example, someone with a badly damaged bone or joint could be treated with nanoparticles which would promote new growth, regrowing the damaged tissue.

Medical nanotechnology also makes cell repair on a molecular level possible, and provides a number of opportunities for medication administration. Drugs developed through nanotechnology could directly penetrate cells, for example, or nanoparticles could be designed to target cancer cells, delivering medication or providing a focal point for radiation. Medical nanotechnology can also be used to make biosensors which can be implanted into patients for monitoring, along with medical devices which are designed to be permanently implanted such as pacemakers.

This field also has a number of implications for prosthetics. Nanomaterials could be used to give people greater control over prosthetic limbs, and potentially to do things like restoring function to the eyes. Several militaries have invested in medical nanotechnology for the purpose of developing new treatments for injured soldiers. The field also creates a potential for the development of devices which could enhance human function, much to the delight of science fiction authors around the world.

Some concerns have been raised about the use of nanomaterials in the medical field. Some people are worried that nanoparticles could interfere with normal body function, making people sick, or that nondevices could get out of control, resulting in activities beyond those for which they are designed. Thus, much of medical nanotechnology is focused on making it safe for patients and medical providers. The history of medicine is filled with examples of concepts and procedures which were initially viewed with deep skepticism and later widely embraced; most people today, for example, widely accept that they should wash their hands regularly, but this idea was heretical when it was introduced in the 1800s.


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