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.
Researchers present materials and device design/fabrication strategies for an array of highly stable and uniform SWCNT-based stretchable electronic devices consisting of capacitors, charge-trap floating-gate memory units, and logic gates (inverters and NAND/NOR gates). The researchers' detailed material, electrical, and mechanical characterizations and theoretical analysis in mechanics provide useful insights in the design and development of SWCNT-based wearable electronic systems.
The most common method for making nanofibers employs electrospinning that uses an electrical charge to draw nanofibers from a polymeric solution. This technique utilizes large voltages and is strongly influenced by the dielectric properties of the material. It is also impossible to electrospin many biopolymers without blending with another polymer. Addressing these drawbacks, a team of researchers report a new method - magnetospinning - which utilizes a simple set-up that is independent of the dielectric constant of the solvent and polymer used.
Classical semiconductor physics suggests that a single charge transport CMOS device cannot achieve ultra-high-performance and ultra-low-standby-power at the same time. Nanoelectronics researchers are trying to design devices that hit the 'sweet spot', i.e. where a charge transport device can provide its highest performance at its lowest power consumption, especially in its 'off' state.
In new work, researchers show a unique device concept which combines the advantages of a tunnel field-effect transistor for ultra-low OFF (leakage) current and ultra-steep sub-threshold slope for sharper and faster ON and OFF switching due to the FET's nanotube architecture.
Presently, several techniques for detecting mRNAs are available,which include in situ hybridization and polymerase chain reaction. However, these single-point and end-point techniques require the killing of the cells and are thus unable to capture the expression of mRNA in real time and locality with high precision. In new work, scientists describe a new way of preparing functional DNA nanostructures that can provide accurate quantification and visualization of mRNA transcripts in living cells.
Counter intuitive to our idea of 'perfection equals best performance', researchers have shown that defects in nanocarbons could provide a breakthrough for increasing the quantum capacitance. By subjecting graphene layers to a reactive-ion etching process, the team has poked holes into graphene to create holey graphene, which can change the microscopic distribution of electrons and thereby increase the quantum capacitance of graphene by at least fourfold.
Upconversion luminesce materials are promising for widespread application ranging from optical devices to biodetection and cancer therapy, the near-infrared light excited upconversion materials are attracting much research attention. Researchers have achieved an ultra-strong and ultra-pure red upconversion in erbium and ytterbium co-doped lutetium oxyfluorides through size and morphology control. These nanoparticles, with extremely strong and pure upconversion are promising candidates as novel luminescent reagents for high-contrast bio-imaging and bio-labeling.