Carbon nanotubes (CNTs) offer a number of advantages for delivering drugs to specific locations inside the body which suggest that they may provide an improved result over nanoparticles. They have a larger inner volume which allows more drug molecules to be encapsulated, and this volume is more easily accessible because the end caps can be easily removed, and they have distinct inner and outer surfaces for functionalization. Recent research has shown the ability of CNTs to carry a variety of molecules such as drugs, DNA, proteins, peptides, targeting ligands etc. into cells - which makes them suitable candidates for targeted delivery applications. Researchers have now developed a unique two-dye labeling method to directly track the release process of a anti-cancer drug from carbon nanotube carriers in living cells.
For years it has been known that scaling bulk silicon transistors would be extremely challenging, if not impossible, when lengths close in on 15 nm. Already, attention has turned to 3D transistor design and silicon-on-insulator (SOI) devices to improve the scalability of silicon technology. Carbon nanotube (CNT) transistors have been touted as a possible replacement for silicon devices but the crucial question so far has been if CNT transistors can offer performance advantages over silicon at sub-10 nm lengths? New experimental results from IBM Research are indicating that the answer is 'yes'. The findings by the research team defied the theoretical projections and exhibited encouraging performance for a device with a 9 nm channel length.
Noble metal nanoparticles such as gold, silver or platinum are widely used by scientists to develop novel applications in sensing, energy, spectroscopy, and catalysis. For instance, the combination of metal nanoparticles and carbon nanomaterials - graphene and nanotubes - has met with great interest in the area of biosensor applications as well as composite fabrication for light-energy conversion. In these applications, researchers make use of the formation of organic/inorganic hybrid nanosystems by incorporating metal nanoparticles in or onto the graphitic structures of carbon nanotubes or graphene. Researchers have now discovered a novel phenomenon whereby graphene can be catalytically transformed into carbon nanotubes by gold nanoparticles at relatively low temperatures.
Theoretical and experimental studies over the past few years have demonstrated that carbon nanotubes (CNTs) could exhibit novel and outstanding electromagnetic effects. Researchers have used this to fabricate various types of CNT nanocomposite materials for electromagnetic interference shielding, outperforming conventional shielding. In new work, scientists have now demonstrated the enhanced X-ray shielding of CNTs. Previously, scientists believed that X-ray attenuation - the gradual loss in intensity of X-rays as they travel through a medium - was determined by the atomic number of a material and that its structure didn't matter. What the team found, though, was that that the mass attenuation coefficient of CNTs was by 20-50% higher than that observed for highly oriented pyrolytic graphite and fullerenes.
Heat has become one of the most critical issues in computer and semiconductor design. Three factors are playing the most important role in a microscale heat sink cooling system: the thermal conductivity of the material of the cooling fins; the heat exchange area of the cooling fins; and the convection between cooling fins and ambient. Carbon nanotubes satisfy the first two factors very well. They possess very high thermal conductivity and very high surface/volume ratio among other outstanding physical properties such as light, high current carrying capacity, excellent mechanical strength, etc. To reduce high temperatures, today's heat sinks are attached to the back of the chips to pull thermal energy away from the microprocessor and transfer it into the surrounding air. Researchers have now demonstrated the application of interface-enhanced CNTs as on-chip cooling fins in a microchannel heat sink.
A number of parameters are known to affect the synthesis of carbon nanomaterials, such as the composition and size of the catalysts, type of hydrocarbon gas, temperature, and reaction time. Different carbon nanomaterials having various carbon atomic configurations demonstrate different physical and chemical properties. As a result, it is critical to synthesize carbon nanomaterials with controlled morphology and internal structures for their potential applications as building blocks for nanoscale electronics and photonics, catalyst supports for fuel cells, non-viral carriers for delivering biomolecules into cells, biomedical imaging, and additives for reinforced composite materials. In order to overcome these barriers, researchers need to investigate the interactions between catalysts and carbon nanomaterials to understand how the catalyst facilitate the growth of carbon nanomaterials and, thereby, obtain carbon nanomaterials with controlled properties through tailoring of their catalyst parameters.
Implantable devices like pace makers or neurostimulators are powered by lithium batteries whose service life is as low as 10 years. Hence, many patients must undergo a major surgery to check the battery performance and replace the batteries as necessary. A team in Japan has now reported an interesting strategy that would keep using batteries but provides a mechanism for remotely recharging them from outside the body by converting laser light into thermal energy and subsequently to electricity. The main purpose of this study was to show that it is possible to remotely control electrical energy generation by laser light that can be transmitted through living tissue in order to target various bionic applications implanted in the body.
Ultra- or supercapacitors are emerging as a key enabling storage technology for use in fuel-efficient transport as well as in renewable energy. These devices combine the advantages of conventional capacitors - they can rapidly deliver high current densities on demand - and batteries - they can store a large amount of electrical energy. Supercapacitors offer a low-cost alternative source of energy to replace rechargeable batteries. Although the energy density of capacitors is quite low compared to batteries, their power density is much higher, allowing them to provide bursts of electric energy. Researchers have now fabricated novel high-performance sponge supercapacitors using a simple and scalable method. Their results shows that three-dimensional electrodes potentially have a huge advantage over conventional mixed electrode materials.