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Showing Spotlights 993 - 1000 of 2024 in category (newest first):

 

Water desalination with graphene

waterA relatively new method of purifying brackish water is capacitive deionization (CDI) technology. The advantages of CDI are that it has no secondary pollution, is cost-effective and energy efficient. The basic concept of CDI, as well as electrosorption, is to force charged ions toward oppositely polarized electrodes through imposing a direct electric field: brackish water flows between pairs of high surface area carbon electrodes that are held at a potential difference of about 1-2 volts. The ions and other charged particles, such as microorganisms, are attracted to and held on the electrode of opposite charge. A research team has now developed a CDI application that uses graphene-like nanoflakes as electrodes for capacitive deionization. They found that the graphene electrodes resulted in a better CDI performance than the conventionally used activated carbon materials.

Posted: Oct 27th, 2010

'Cooking' sharper AFM tips in a microwave oven

afm_tipIn atomic force microscopy (AFM), tip quality depends mainly on the dimensions and shape of the probe, the durability of the tip apex, and the nature of the interaction between sample and probe. With this in mind, researchers have experimented with mounting ultra sharp and high aspect ratio carbon nanotube (CNT) bundles onto the apex of an AFM tip to improve spatial and potential resolution. Although AFM tips functionalized with a carbon nanotube have attracted considerable attention, attaching CNTs to scanning probes is not a trivial matter, which limits their practical use. An alternative approach, whereby a CNT is grown onto the AFM tip, also can be very time-consuming and requires a costly set-up. A team at the Friedrich-Schiller-University Jena in Germany has now demonstrated a fast and cheap process for the fabrication of carbon nanotube AFM tips with the help of microwave ovens.

Posted: Oct 26th, 2010

A nanomedicine approach for ocular neuroprotection in glaucoma

eyeMedical researchers believe that the best way to protect eye from glaucoma is to protect the optic nerve from a sudden increase in intraocular pressure since ocular hypertension is the most important risk factor for glaucoma. Accordingly, for the past few years, huge research efforts have been made to develop a powerful biotechnical approach to protect the optic nerve. As a result, scientists discovered that Heat Shock Proteins (HSPs) can be a new powerful modality for the protection of optic nerves - ocular neuroprotection - from glaucoma. Although a variety of methods to induce HSPs have been developed and tried, they all were found to be ineffective for the induction of HSPs from the optic nerve due to side effects including chemical and physical side effects. A novel nanomedicine modality has now been shown to be feasible for ocular neuroprotection in glaucoma cases.

Posted: Oct 25th, 2010

Novel nanopatterning technique uses liquid bridge to transfer materials from mould to substrate

nanopatterningMany nanotechnology research projects require some form of nanopatterning technique in fabricating the devices, structures and surfaces required. With the current state of micro- and nanofabrication, the direct printing of functional materials is the most efficient method at low cost and low environmental impact. A direct printing approach has the merits of forgoing complex and expensive equipment, reducing the fabrication processes, saving the amount of material used, and removing chemical exposure in the processes. However, imprinting methods suffer from residues and difficulty in multi-alignment. Researchers in Korea have now developed a direct printing technique that is based on a liquid-bridge-mediated transfer moulding process.

Posted: Oct 20th, 2010

Nanodiamonds could revolutionize the current styrene synthesis industry

nanodiamond_catalystCatalytic dehydrogenation of ethylbenzene is one of the most important processes in the chemical industry world-wide. Styrene, for instance, is commonly produced using this process. The annual production of some 20 million metric tonnes of styrene is an important precursor in the plastics industry. Being able to develop a new metal-free, energy-saving, and efficient catalyst for alkane dehydrogenation would have a significant positive impact on the environment. Coke formation during the current industrial process is the main disadvantage of the metal-based catalysts now used. Steam is used as a protection agent to avoid coking and thus keep the catalysts active. The steam generation consumes massive amounts of energy. This is simply solved by using carbon as catalyst material. Even without steam, the catalyst is free from coke formation and shows long time stability. Researchers have now developed a new process for the dehydrogenation of ethylbenzene, using nanodiamonds as catalyst, that is oxygen-free and steam-free.

Posted: Oct 18th, 2010

Electrofluidics device uses sub-10nm nanochannels to analyze DNA

nanochannelsIn order to improve throughput speed of DNA sequencing and reduce its cost, researchers are pursuing real-time solid-state DNA sequencing devices. To that end, electronic functional devices in liquid environments need to be developed, ideally utilizing the compatibility with current complementary metal oxide semiconductor (CMOS) based fabrication technology. In this regard, the combination of electronics and nanofluidics leads to the field of electrofluidics, which utilizes the electrical behaviors of fluids for solid state device applications. In order to explore the ion transport and biomolecule transport through nanochannels, researchers have now reported the fabrication of an electrofluidic platform to study the motion of single molecules, including DNA. The device's nanochannel structures were fabricated with sub-lithographic dimension through top-down based, conventional semiconductor fabrication methods.

Posted: Oct 14th, 2010

Nanotechnology improves wool fabrics

superhydrophilic_wool_fabricsNanotechnology shows great potential for revolutionizing the textile industry across its entire range of applications with its ability to impart new functionality to textiles while at the same time maintaining their look and feel. The wool textile industry, for example, is researching the development of textiles with fast-absorbing and quick-drying properties. This has great importance for improving clothing thermophysiological comfort and wearing performance by adjusting the transport of heat and moisture through a fabric which was usually achieved using synthetic fibers. One stubborn hurdle that prevents nanotechnology-enabled 'smart' textiles from becoming more of a commercial reality is the insufficient durability of nanocoatings on textile fibers or the stability of various properties endowed by nanoparticles. Quite simply put, the 'smart' comes off during washing. Developing an effective approach to enhance the coalesce force between nanoparticles and wool fibers has great significance both in scientific and real applications of nanotechnology functionalized textiles.

Posted: Oct 12th, 2010

Novel graphene amplifier is a major step from single devices to circuits

graphene_transistorSo far, there have been no research reports on a graphene-based transistor amplifier and investigations of its in-field controllability for analog, mixed-signal, and radio-frequency applications. Previous work on graphene transistors has largely focused on frequency multiplication near the Dirac point in graphene current-voltage characteristic. But now, a team of researchers has demonstrated the first triple-mode graphene amplifier. They have shown experimentally that by leveraging the ambipolarity of charge transport in graphene, the amplifier can be configured in the common-source, common-drain, or frequency multiplication mode of operation by changing the gate bias. This is the first demonstration of a single-transistor amplifier that can be tuned between different modes of operation using a single three-terminal transistor. Moreover, during its operation, the graphene amplifier was configured in-field to switch between the different modes. The result marks another important step toward graphene applications in electronics.

Posted: Oct 11th, 2010