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Nanotechnology Spotlight

Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles

Showing Spotlights 129 - 136 of 1603 in category (newest first):

 

High-performance graphene transistor with high room-temperature mobility

graphene_transistorUtilization of graphene may help realize innovative low power replacements for III-V materials based high electron mobility transistors while extending operational frequencies closer to the THz regime for superior wireless communications, imaging, and other novel applications. Device architectures explored to date suffer a fundamental performance roadblock due to lack of compatible deposition techniques for nanoscale dielectrics required to efficiently modulate graphene transconductance while maintaining low gate capacitance-voltage product. In new work, researchers have shown that a double layer of graphene with structural transformation to a striped channel architecture can produce high field effect mobility at a very low operation voltage.

Posted: Jun 26th, 2013

Nanoscale chemistry allows microfluidics without channels and troughs

dropletIn a seminal paper more than 20 years ago, scientists described a device that was capable of causing drops of water placed on it to move uphill. However, as it turned out in subsequent research, drops of water are notoriously difficult to move from where they lie, unless they are large enough to be moved by gravity. In the absence of a microtube or of a channel - as they are required by most microfluidic devices - it usually is not possible to apply the pressure needed to induce liquid movement. An alternative approach, developed by researchers in Italy, is to pattern a gradient on a surface which allows a droplet to move in order to minimize its free energy.

Posted: Jun 25th, 2013

3D nanolithography without the expensive hardware

nano-volcanoWhile researchers are working on developing more cost-effective nanolithographic tools such as for instance superlens lithography, one of the key problems with nanofabrication is how to generate ever-challenging patterns with high resolution - especially for 3D nanostructures - and at the same time substantially reduce the cost of the process. A novel nanolithography method is based on light scattering from nanoparticles, which can generate 3D hollow-core structures that resembles 'nano-volcanoes'. Different from traditional lithography methods that are typically based on complex systems, this process relies solely on the light interaction with a single nanoparticle. No masks and external optics are needed in this approach, and light is manipulated into the desired optical pattern solely by the colloids.

Posted: Jun 24th, 2013

Innovative nanoparticle therapy to treat infected burn wounds

burn_woundDespite significant advances in the medical/surgical management of severe thermal injury, wound infection and subsequent sepsis persist as frequent causes of morbidity and mortality for burn victims not only due to the extensive compromise of the protective barrier against microbial invasion, but also as a result of growing pathogen resistance to our therapeutic options. Researchers have now demonstrated that encapsulating Amphotericin B, a intravenously administered potent fungicidal polyene macrolide, in nanoparticles increased its killing impact against numerous candida species, was more effective at preventing candidal biofilm formation, and cleared a mouse burn model infected with candida more effectively than solubilized amphotericin.

Posted: Jun 21st, 2013

Atomic resolution images show what happens when lithium ions enter battery electrodes

battery_electrodeIn terms of weight and size, batteries have become one of the limiting factors in the continuous process of developing smaller and higher performance electronic devices. To meet the demand for batteries having higher energy density and improved cycle characteristics, researchers have been making tremendous efforts to develop new electrode materials or design new structures of electrode materials. Researchers have now investigated the atomistic nature of the lithiation mechanism in individual tin dioxide nanowires by in situ transmission electron microscope and complementary density functional theory simulation.

Posted: Jun 19th, 2013

New technique precisely determines nanoparticle uptake into individual cells

nanoparticles_inside_cellWhile nanoparticles are emerging as drug carriers for targeted nanomedicines, preclinical assays to test nanoparticle efficacy are hampered by the lack of methods to quantitatively determine internalized particles. A novel method is suited to pave the way for preclinical testing of nanoparticles to establish dose-efficacy relationships and to optimize biophysical and biochemical parameters in order to make better drug delivery vehicles. The team demonstrated that it is possible to determine the exact number of nanoparticles inside a cell through a combination of three methods and a mathematical model which they developed to link the data from these three methods.

Posted: Jun 18th, 2013

Destroying cancer cells by remote activation of intracellular nanoparticles

cancer_cellUnder an applied magnetic field, iron oxide nanoparticles trigger cancer cell death by bursting intracellular organelles. These findings offer a new strategy to treat cancer using nanomaterials. Researchers may be able to administer magnetic nanoparticles externally, allow them to accumulate at the tumor site, and then irradiate them with a magnetic field to induce cancer cell death. In the past, antibodies and small molecules were used to trigger apoptosis in cancer cells. However, cancer cells often adapt to resist these treatments. Because iron oxide nanoparticles cause physical damage to cancer cells, it is difficult for them to develop resistance.

Posted: Jun 14th, 2013

Capture and release of individual cancer cells with fractal nanostructures

fractal_nanostructureFractals are structures built up from repeated sizings of a simple shape to make a complex one. A fractal is a geometric structure that can repeat itself towards infinity. Zooming in on a fragment of it, the original structure becomes visible again. In biological systems, fractal structures can be found everywhere - bronchial trees, vasculature, and nerve cells. These amazing structures can provide a specific interfacial contact mode that is highly efficient for absorbing sunlight, transporting nutrition, exchanging oxygen and carbon dioxide, and signal transduction. Researchers have now demonstrated the fabrication of programmable fractal gold nanostructured interfaces and their outstanding specific recognition of rare cancer cells from whole blood samples along with their effective release capability.

Posted: Jun 13th, 2013