In conventional nanosphere lithography, the nanosphere configurations in the layers are determined by a spontaneous self-assembly process. Therefore, the final configurations are limited to those with or close to the minimal free energy giving rise to very simple patterns. Researchers have now managed to circumvent this thermodynamical restriction by putting the monolayers in a confined environment and constructing the bilayers with sequential stacking, both of which are critical for the formation of moire patterns.
While exploring the possibility to realize graphene-like nanostructures of boron, carbon's neighbor in the periodic table, a team of chemical engineers has discovered an entirely new family of 2-D compounds. They demonstrated exfoliation of a well-known superconductor magnesium diboride, a layered material that consists Mg atoms sandwiched in between born honeycomb planes. These nanosheets can be an order of magnitude more transparent compared to their cousin graphene.
The key challenges associated with the development of high performance MEMS and NEMS resonators for RF wireless communication and sensing applications are the isolation of energy-dissipating mechanisms and scaling of the device volume in the nanoscale size-range. Researchers show that graphene-electrode based piezoelectric NEMS resonators operate at their theoretical 'unloaded' frequency-limits, with significantly improved electromechanical performance compared to metal-electrode counterparts, despite their reduced volumes.
Researchers have developed a novel 3D-printing based method to produce highly monodisperse core/shell capsules that can be loaded with biomolecules such as therapeutic drugs. The method provides a robust control over particle properties, passive release kinetics, and particle distributions throughout a 3D matrix. Furthermore, these capsules are rendered stimuli-responsive by incorporating gold nanorods into the polymer shell, allowing for highly selective photothermal rupture and triggered temporal release of the biomolecular payload.
Over the last twenty years, scientists have developed many techniques to synthesize polymeric nanoparticles for a wide range of applications including surface coating, sensor technology, catalysis, and nanomedicine. However, the precise control of the size and shape of polymer nanoparticles remains challenging, and RDRP techniques still fall well short of producing large, well-defined macromolecules with the same size and degree of precision as nature (proteins, nucleic acids, etc.). In new work, researchers have developed a new technique to precisely control the size and shape of polymeric nanoparticles.
According to Planck's law, the emittance of a non-reflective black object - a blackbody - defines the maximum level of thermal emittance from an arbitrary object. Planck's law has been challenged in recent decades by predictions and successful demonstrations of the radiative heat transfer between objects separated by nanoscale gaps that deviate significantly from the law predictions. Researchers have now demonstrated another way to modify the object thermal emission spectrum and to force it to deviate from the one predicted by Planck's law.
Graphene acts as an excellent conductor to electric fields along its flat surface and as an insulator perpendicular to the surface. Due to this anisotropic nature of graphene's conductivity, graphene flakes have potential applications in nanoscale switches and nano-electromechanical systems. Controlling the orientation of graphene flakes therefore has drawn a great deal of research interest in nanotechnology. In new work, researchers have developed a technique to control the orientation of graphene flakes at the nanoscale by using a nematic liquid crystal platform.
Magnetic field sensors are in very high demand for precise measurements of position, proximity and motion. The most commonly used Hall Effect devices are fabricated with silicon. The sensitivities of these sensors - voltage and current - depend on the device materials electronic properties such as charge carrier mobility and density. However, for futuristic advanced applications higher sensitivity Hall sensors are required than can be achieved with silicon. Researchers now have set a new world record for the sensitivity of Hall sensors using highest quality graphene encapsulated in hexagonal boron nitride.