With the semiconductor industry still on the path of Moore's law, researchers have already been toying with single-molecule electronics and molecular memory to push miniaturization of electronics to its limit. However, with electrical gadgets and devices getting increasingly smaller and functionally more powerful, the current density flowing through the copper and gold conductors in these devices has been exponentially increasing. Therefore, electrical conductors with higher current density tolerance are in huge demand and recent research has addressed this issue.
Microbial fuel cells are a prime example of environmental biotechnology that turns the treatment of organic wastes into a source of electricity. In microbial fuel cells, the naturally occurring decomposing pathways of electrogenic bacteria are used to both clean water and produce electricity by oxidizing biological compounds from wastewater and other liquid wastes, even urine. Researchers have now demonstrated a sustainable and practical design for a micro-sized microbial fuel cell.
Direct visualization and manipulation of individual carbon nanotubes (CNTs) in ambient conditions is of great significance for their characterizations and applications. However, the direct visualization, location, and manipulation of individual CNTs is extremely difficult due to their nanoscale diameters. The observation of individual CNTs usually requires electron microscopes under high vacuum. Researchers now have proposed a facile way to realize optical visualization of individual carbon nanotubes and, based on that, macroscale manipulation of individual carbon nanotubes that could be carried out under an optical microscope.
Electronics will undergo revolutionary changes as the relatively novel disciplines of spintronics, nanoelectronics, and quantum computing come of age. A fundamental link between these fields can be established using molecular magnetic materials and, in particular, single-molecule magnets. Researchers have now demonstrated how to noninvasively graft a single-molecule magnet onto a carbon nanotube nanoelectromechanical system and probe the molecular nanomagnet with the carbon nanotube's mechanical motion.
Liquid-solid phase transitions can be an attractive route for the temperature regulation of electrical and/or thermal properties because of the availability of materials with a wide range of phase transition temperatures. Achieving different magnitudes of enhancement in solid and liquid state is difficult to explain from a theoretical point of view. When researchers made similar experiments using single-walled carbon nanotubes as the additives, they noticed much higher thermal conductivity improvement than the evidence available in existing literature. This is something they never anticipated to happen and they were quite surprised with the enhancement seen.
One of the problems researchers have to struggle with in exploiting the extraordinary mechanical properties of carbon nanotubes (CNTs), for instance for building superstrong fibers or T-shirt-thin ballistic armors, has been the question of how to synthesis CNTs with macroscale lengths and without decreasing areal density. A crucial step for realizing such applications will be the ability to mass-produce carbon nanotubes with meter-scale or even kilometer-scale length and excellent mechanical properties. In new work, a team of researchers from Tsinghua University in Beijing have found that the growth of ultralong carbon nanotubes could be described using Schulz-Flory distribution, which is very common in polymer science.
Nanotechnology-enabled, paper-based sensors promise to be simple, portable, disposable, low power-consuming, and inexpensive sensor devices that will find ubiquitous use in medicine, detecting explosives, toxic substances, and environmental studies. Since monitoring needs for environmental, security, and medical purposes are growing fast, the demand for sensors that are low cost, low power-consuming, high sensitivity, and selective detection is increasing as well. Paper has been recognized as a particular class of supporting matrix for accommodating sensing materials. A team of Chinese researchers has now developed low-cost gas sensors by trapping single-walled carbon nanotubes in paper and demonstrated their effectiveness by testing it on ammonia.
Flexible electronics are all the rage these days. They promise an entirely new design tool like for instance, tiny smartphones that wrap around our wrists, and flexible displays that fold out as newspapers or large as a television; or photovoltaic cells and reconfigurable antennas that conform to the roofs and trunks of our cars. This article reviews the progress in single-walled CNT and graphene-based flexible thin-film transistors related to material preparation, fabrication technique and transistor performance control, in order to clarify the possible scale-up methods by which mature and realistic flexible electronics could be achieved.