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.
The European Commission acknowledges that nanomaterials are revolutionary materials and that important challenges exist in regard to hazard and exposure assessments. Yet, they conclude that current risk-assessment methods are applicable to nanomaterials. Scientists argue that significant changes to REACH and the accompanying annexes are required to answer the call made by the public, downstream users and progressive businesses for clearer and more definite regulatory rules specific to nanomaterials.
The degree of competitiveness in sports has been remarkably impacted by nanotechnology like any other innovative idea in materials science. Within the niche of sport equipments, nanotechnology offers a number of advantages and immense potential to improve sporting equipments making athletes safer, comfortble and more agile than ever. Baseball bats, tennis and badminton racquets, hockey sticks, racing bicycles, golf balls/clubs, skis, fly-fishing rods, archery arrows, etc. are some of the sporting equipments, whose performance and durability are being improved with the help of nanotechnology. Nanomaterials such as carbon nanotubes, silica nanoparticles, nanoclays fullerenes, etc. are being incorporated into various sports equipment to improve the performance of athletes as well as equipments.
Nanomaterials hold promise as synthetic vaccines. They have the ability to deliver cargo to specific immune cells and modulate the resulting immune response. Compared to natural vaccine vectors, including engineered viruses or attenuated pathogens, synthetic nanoscale vaccines are safer, more controlled, and have the potential to be more effective. Nanoscale vaccines may also prevent, or even treat a wider range of diseases, including cancer. Researchers now have developed nanoscale polymer micelles that elicit both humoral and cellular immunity. The constructs could help in the fight against infectious diseases and cancer.
Nanotechnology is helping to revolutionize cancer hyperthermia - the treatment of cancer with heat. Certain types of nanoparticles, in particular those made of gold or iron oxide, act as transducers that absorb electromagnetic radiation and generate heat. If the nanoparticles are delivered selectively to a tumour, heat can be generated within the tumour tissue by irradiating it with an external energy source. This results in heat-induced cell death within the tumor, sparing the surrounding healthy tissues. Researchers have now developed gold nanoparticles coated with a temperature-sensitive dye. The constructs allow nanoparticle-induced heating to be monitored locally.
Researchers have come up with various electrode materials to improve the performance of supercapacitors, focussing mostly on porous carbon due to its high surface areas, tunable structures, good conductivities, and low cost. Graphene and carbon nanotubes show great potential but are costly. Researchers in Canada have now reported the successful hydrothermal-based synthesis of two-dimensional, yet interconnected, carbon nanosheets with superior electrochemical storage properties comparable to those of state-of-the-art graphene-based electrodes.
Ferromagnetic materials exhibit the so-called anomalous Hall effect (AHE), whereby the electrons flowing through the material experience a lateral force pushing them to one side as a result of the material's intrinsic magnetization. Although the AHE has been used in the field on nanotechnology to measure the magnetic behavior of nanoparticles (with sizes larger than 50 nm), nobody so far had tried to separate the signals of the individual particles. Researchers in Germany have now developed a simple technique which allows to measure the magnetic response of single ferromagnetic nanoparticles down to a radius of about 3.3 nm.
The low-frequency 1/f noise is a ubiquitous phenomenon found everywhere from fluctuations of human heart rates to fluctuations of electrical currents in semiconductor devices. An acceptable level of flicker 1/f noise is one of the key metrics that each new material has to pass before it can be used for practical devices. Graphene has shown a great potential for applications in high-frequency communications, analog circuits and sensors. The envisioned applications require a low level of 1/f noise, which contributes to the phase-noise of communication systems and limits the sensor sensitivity. Now, researchers have discovered a unique feature of 1/f noise in graphene, which can help understand its microscopic origin and develop new techniques for noise reduction.