Graphene, one of the most exciting two-dimensional materials, has shown extraordinary optical properties due to strong surface plasmon polaritons supported by graphene nanostructure. Graphene metasurfaces show plasmonic resonance bands that can be tuned from mid-infrared to terahertz regime. These plasmonic devices can be used for biosensing, spectroscopy, light modulation and communication applications. Researchers now demonstrate for the first time an effective method to pattern large area graphene into moire metasurfaces with gradient nanostructures having multiband resonance peaks in mid infrared range.
Whether it is possible to achieve high formability in quasicrystals and how quasicrystals are plastically deformed at room temperature have been long-standing questions since their discovery. In new work, an international group of researchers has found that a typically brittle quasicrystal exhibits superior ductility (ductility is a solid material's ability to deform under stress without fracture) at the sub-micrometer scales and at room temperature. Furthermore, their experiments indicate that 'dislocation glide' could be the dominating deformation mechanism for quasicrystals under high-stress and low temperature conditions, which has been not poorly understood before.
The entry of nanotechnology into manufacturing has been compared to the advent of earlier technologies that have profoundly affected modern societies, such as plastics, semiconductors, and even electricity. Applications of nanotechnology promise transformative improvements in materials performance and longevity for electronics, medicine, energy, construction, machine tools, agriculture, transportation, clothing, and other areas. However, the path to greater benefits from nanomanufactured goods and services is not yet clear. This review takes silicon integrated circuit manufacturing as a baseline in order to consider the factors involved in matching processes with products, examining the characteristics and potential of top-down and bottom-up processes, and their combination.
Poisson's ratio describes the fundamental elasticity of any solid. Poisson's ratio has been a basic principle of engineering for more than 200 years as it allows engineers to identify how much a material can be compressed and stretched and how much pressure it will withstand, before it collapses. Materials with a negative Poisson's ratio are relatively rare and it has recently become popular in referring to them as metamaterials - a group of materials that attain interesting or extreme properties via structure rather than composition.
Oral cancer represents one of the most dreadful killer diseases globally. Researchers have developed nano-sized layer by layer (LbL) assembled polyelectrolytes onto calcium carbonate particles to deliver small molecule tyrosine kinase inhibitors to human oral cancer cells. Calcium carbonate is a naturally occurring inorganic mineral with a porous structure generates a large surface area. It is biocompatible, biodegradable, acts as a sacrificial core template, and offers the opportunity to capture effectively a myriad molecules of interest like drugs, proteins, enzymes, etc. The researchers encapsulated sorafenib - a tyrosine kinase inhibitor - in CaCO3 nanoparticles, which was layered alternatively with biodegradable polyelectrolytes to form a multilayer shell.
Researchers have developed a highly manufacturable integration strategy for making 3D flexible sensor arrays and connecting them to control electronics based on the widely popular phrase, 'Two sides of the same coin'. Sensor arrays and control elements for flexible electronics devices are usually placed on the same plane, unnecessary requiring additional area, and causing problems of heat dissipation. These challenges motivated researchers to come up with an area-efficient solution for the problem of connecting sensors and electronics together in such a way that electronics can be kept away from the sensed surface. This is the first time ever the concept of double sided flexible 3D electronics has been introduced in the flexible and wearable electronics industry.
A major challenge in nanotechnology is that of determining how to introduce green and sustainable principles when assembling individual nanoscale elements to create working devices. For instance, textile nanofinishing is restricted by the many constraints of traditional pad-dry-cure processes, such as use of costly chemical precursors to produce nanoparticles, high liquid and energy consumption, production of harmful liquid wastes, and multistep batch operations. By integrating low-cost, scalable, and environmentally benign aerosol processes, these constraints can be circumvented while leading to a new class of multifunctional fabrics.
The serious threat of particulate matter (PM) air pollution to human health spurs development of advanced filter technologies. Particular efforts have been made in designing air filters with both high filtration efficiency and low airflow resistance by utilizing carbon nanotubes and electrospun polymer and inorganic nanofibers. In new work, scientists explored the performance of electrospun silk nanofiber membranes as air filters, which showed both of lightweight and high efficient features.