Super-tough materials with exceptional mechanical properties are in critical need for applications under extreme conditions such as jet engines, power turbines, catalytic heat exchangers, military armors, airplanes, and spacecraft. Researchers involved in improving man-made composite materials are trying to understand how some of the amazing high-performance materials found in nature can be copied or even improved upon. Nature has evolved complex bottom-up methods for fabricating ordered nanostructured materials that often have extraordinary mechanical strength and toughness. The main problem in making nanocomposite materials is how the separate components can be interfaced without losing the good properties of each component. Researchers were now able to show that biomolecules that may seem soft and fragile can actually strengthen a composite material by creating cohesion between two materials that differ much from each other.
Single-molecule magnets (SMM) are fascinating nanoscale structures with unique functional properties showing promise for high-density electronic data storage devices, solid state quantum computers, spintronic devices such as spin valves, and other advanced technological applications. Despite a flurry of research in this area - since an individual magnetic molecule represents the ultimate size limit to storing and processing information - the main challenge related to harnessing properties of SMM remained unsolved. A new study by a group of European researchers reports the successful encapsulation of single-molecule magnets in carbon nanotubes, yielding a new type of hybrid nanostructure that combines all the key single-molecule magnet properties of the guest molecules with the functional properties of the host CNT.
Integrating biological molecules or even complex molecular machines with man-made nanoelectronic devices is one of the ultimate goals of bionanotechnology. Already there is a growing community of researchers interested in this area of bio/nano integration where biological components are interfaced with inorganic nanomaterials to create new devices and systems that combine the desirable properties of each system. One particular nanomaterial used in this kind of research are carbon nanotubes (CNTs). Scientists now report the integration of a CNT transistor with olfactory receptor proteins. The ultimate goal of this type of research is to transfer the sensing properties of biological molecular systems to artificial electronic devices.
There is a growing body of research on using carbon nanotubes (CNTs) and other nanomaterials in neural engineering. Scientists are already exploring the feasibility of using CNTs to probe neural activity. With this research comes the need to develop a unified approach when assessing the toxicity of CNT in neurons. However, a complex picture emerges from the reported data: is it feasible to develop CNT-based devices as drug delivery vectors? Ultimately, are soluble CNT neurotoxic, and, if yes, to what degree? Given the often conflicting results of research reports on the biocompatibility of soluble CNT when administered to neurons in the central nervous system, a review article helps to clarify which aspects (technical or methodological) of these studies may be responsible for their heterogeneous conclusions.
Energy generation and storage is an important issue at the nanoscale. For tiny devices such as nano- and micro-electromechanical systems, autonomous power sources are crucial for practical applications. Progress is being made in designing and fabricating nanoscale power generators. But, as with the large, macroscale systems of future smart grids, there might be times when powered nanodevices need to bridge a slump in power generation/harvesting or they might be designed to run on stored energy altogether for a limited period of time. Researchers in China are now proposing that the high energy density and power density of carbon nanotubes makes them promising materials for the storage of mechanical energy. The team provides a structural model towards mechanical energy storage for nanodevices and also demonstrates a method to characterize and manipulate ultralong CNTs.
Blood platelets are the structural and chemical foundation of blood clotting and they play a vital role in minor injuries when coagulation prevents the loss of blood at the injury site. If the proper function of these platelets gets disturbed, blood clotting can lead to thrombosis, which is a leading cause of death and disability in the developed world. In view of the rapid development of nanotechnology, the impact of the newly engineered nanomaterials as an additional thrombosis risk factor is not yet known but should not be underestimated. In fact, it has been reported that carbon nanotubes induce platelet aggregation and potentiate arterial thrombosis in animal model. However, a mechanism of thrombogenic effects of carbon nanotubes was not known. Researchers have now shown that show the molecular mechanism of carbon nanotubes' induced platelets activation.
Current production methods for carbon nanotubes (CNTs) result in units with different diameter, length, chirality and electronic properties, all packed together in bundles, and often blended with some amount of amorphous carbon. Often, these mixtures are of little practical use since many advanced applications, especially for nanoelectronics, are sensitively dependent on the structures. Separation of nanotubes according to desired properties is still proving to be a challenging task, especially single-walled carbon nanotube (SWCNT) sorting. The composition of SWCNTs of different types is very similar, but the chemical properties are not. Conventional separation techniques are efficient in separation of carbon nanotubes, but there are many drawbacks. Researchers in Asia have now developed a simple way to realize the separation of single-walled carbon nanotubes via the interaction difference between chemicals and carbon nanotubes.
Apart from making graphene, graphene oxide itself itself is a fascinating material that has many intriguing properties. Researchers have now developed a graphene-based conductive glue that can function as a metal-free solder for creating mechanical and electrical connections in organic optoelectronic devices. As a proof-of-concept, they fabricated polymer tandem solar cells - multi-junction photovoltaic devices, in which two sub-cells are stacked to achieve higher overall solar absorption - by a direct 'gluing' process. The water-based sticky interconnect and the associated adhesive lamination process could transform the serial layer-by-layer fabrication of tandem devices into a parallel mode, in which the subcells can be independently fabricated and adjusted to balance their photocurrents for achieving high efficiency.