Nanowerk Nanotechnology Spotlight
Researchers report an interesting phenomenon of two-dimensional (2D) hexagonal boron nitride (h-BN)-induced planar-alignment of a nematic liquid crystal and the subsequent optical and electro-optical effects. Liquid crystals (LCs) are optically anisotropic materials, and they are widely used in electro-optical display technology, known as liquid crystal displays (LCDs). Understanding the alignment phenomena of a nematic LC on a surface remains an important area of research, as the alignment process determines the LC's molecular orientation and conformation - which influence the LC's optical and electro-optical characteristics in LCDs. • Email to a friend • Recent developments in hydrogel chemistries, reinforcement approaches, and crosslinking methods have expanded the applications of 3D bioprinting to pharmaceutics, regenerative medicine, and biomedical devices. A multitude of 3D bioprinting techniques have been developed, but among these different approaches, extrusion-based 3D bioprinting has become a popular technique as it is easy to optimize and all its constituents are economical in price. A recent review elucidates the nuances of 3D bioprinting in a step-by-step guideline format, from its basics to more advanced levels. • Email to a friend • Understanding the alignment phenomena of a nematic liquid crystals on nanostructured surfaces remains an important area of research, as the alignment process determines the LC's molecular orientation and conformation - which influence the LC's optical and electro-optical characteristics in modern LCDs. Researchers report that an inorganic nanostructured surface - vertically aligned carbon nanotube arrays - can be employed as the alignment agent to design an electro-optic homeotropic LC device. • Email to a friend • Researchers have developed a new type of optical manipulation method to achieve versatile manipulation of objects with different sizes and types using optical heating. In this new technique, nanoparticles get trapped at temperature hot spots instead of electrical hot spots, which demonstrates a different working mechanism and approach from the traditional optical manipulation techniques. Due to this unique working principle, stable trapping of large metallic nanoparticles and miniscule quantum dots on single nanoantennas with extremely low optical power is achieved. • Email to a friend • The use of TiO2 nanoparticles activated by light and ultrasound has been studied extensively for cancer treatments. For the first time, researchers have shown the nanoparticles can be effectively activated by microwaves for cancer cell destruction - potentially opening new doors for patients fighting cancer. They propose the use of microwaves and TiO2 nanoparticles to induce the production of reactive oxygen species (ROS), which has the potential to be a safer, more effective modality for cancer treatment. • Email to a friend • There is a huge effort underway to use memristor devices in neuromorphic computing applications and it is now reasonable to imagine the development of a new generation of artificial intelligent devices with very low power consumption (non-volatile), ultra-fast performance and high-density integration. In new work,r esearchers were not only able to achieve to small switching effects in memristors using light, they take advantage of a percolating-like nanoparticle morphology to vastly increase the magnitude of the switching between electronic resistance states when light is incident on the device. • Email to a friend • Any working electronic device is the source of electromagnetic (EM) radiation. Device miniaturization and a consequent increase in the heat and electromagnetic (EM) wave emission in the electronic systems make the simultaneous heat management and electromagnetic interference (EMI) shielding crucially important. New research shows that the extremely high thermal conductivity of graphene and good electrical conductivity, even without the energy band-gap, make graphene promising for EMI shielding and thermal management applications. • Email to a friend • Imagine catching a comet. Now imagine the comet is as small as a few billionths of meters and it is made of elements from the periodic table that do not like each other; whose fate is that of separate in space and dissolve in biological environments or just in air. Before this happens, the elements are trapped in what is called a non-equilibrium alloy nanoparticle. Since this nanoalloy changes over time, it is not enough to provide its composition and size at a given time, but one should know also how it will change in the near future, or how it changed in the near past. • Email to a friend • Researchers have provided an example of on-demand control of quantum phenomena to design the quantum materials. By state-of-the-art quantum mechanical simulations, they find that a two-dimensional transition-metal ditelluride, MoTe2, can realize a structural phase transition from the semiconducting phase to the topological phase triggered by photoexcitation of carriers alone. The sub-picosecond phase transition can be controlled by varying the laser wavelength. The research is inspired by the classical phase transition theory proposed by Lev Davidovich Landau and Rudolf Ernst Peierls. • Email to a friend • The physicochemical properties of nanoparticles alone cannot predict the fate of nanoparticles in biological systems. Current evidence suggests that the formation of a corona on the nanoparticle surface is the most important parameter that controls nanoparticle toxicity. Scientists now showed that protein corona modulates internalisation and cytotoxicity of nanodiamonds in non-phagocytic and phagocytic cells. Specifically, they found that corona made of bovine serum albumin (BSA), which represents the most abundant protein in blood plasma, reduced nanodiamond agglomeration. • Email to a friend • Periodically strained graphene harbors correlated electronic phases similar to those previously observed in magic angle twisted bilayer graphene. By precisely rotating two stacked sheets of graphene one can induce superconducting and insulating phases depending on the electric density. This behavior is extremely desirable because it significantly reduces energy losses in electronic devices making them more efficient and durable. Researchers have now proposed an alternative way to obtain similar phases. Their approach relies on periodically straining a graphene sheet rather than stacking layers on top of each other. • Email to a friend • Researchers report an integrated multimodal flexible sensor system comprising a room humidity sensor, a leaf humidity sensor, an optical sensor, and a temperature sensor that can tap into potential physiological health issues of plants. Using stacked ZIS nanosheets as the kernel sensing media, the flexible sensor can not only perceive light illumination at a fast response, but also monitor the humidity with a perdurable steady performance. The researchers measured in real time three primary abiotic stresses - i.e. humidity, light and temperature - that govern the transpiration of plants are measured without signal cross-coupling effect. • Email to a friend • Charge density wave (CDW) is a quantum mechanical phenomenon, which induces distortion in the crystal structures of some low-dimensional (1D or 2D) metals, when the temperature is reduced. Such distorted crystal structure is known as CDW phase and its resistivity is much higher than the original symmetric phase. Since the switching between symmetric and CDW phase can also be made by the application of external electric field, these materials are technologically important and have attracted immense attention in the nanoelectronics community. • Email to a friend • Researchers have discovered a novel 'sandwiched' silicon electrode structure that can withstand 500 cycles and deliver capacities three times larger than graphite. They used freestanding sheets made of carbon nanotubes - bucky papers - for sandwiching silicon nanoparticles. These nanotubes form a quasi-three-dimensional structure and hold silicon nanoparticles together even after 100 cycles and mitigate electrical resistance arising from breaking of particles. The sandwiched silicon anode was able to withstand discharging rates as high as 4C. • Email to a friend • The concept of nanostructuring of battery electrodes is not new; it has been frequently employed to improve the charging speed and, in some cases, stability of Li-ion electrodes. Researchers now demonstrated 3D-interconnected Ni nanowire meshes as current collectors and structural scaffolds for building nanostructured Li-ion electrodes. This material exhibits a semi-ordered structure and is characterized by some of the highest combined porosity and surface-to-volume ratio among macroporous metals. • Email to a friend • Novel complementary nanoelectromechanical (CNEM) switches based on complementary ferroelectric nanocracks integrate the advantages of ferroelectric and nanoelectromechanical switches, such as nonvolatility, quasi-zero OFF-state leakage current and low operating voltage. These ferroelectric crack-based CNEM switches could realize energy-efficient and high-density reconfigurable computing, which can be specialized to a particular task through its universal programmability, offering large flexibility and short time from design to realization. • Email to a friend • The electronic and optical properties of 2D materials can be controlled by mechanical deformations of their crystal structure. This route to tailor the properties of materials is called strain engineering and it is a rapidly evolving field of research in nanomaterials. Straintronics, however, is somewhat hampered by technical issues related to the fast and reliable control of the applied strain. Researchers have now developed a versatile and straightforward platform to control the biaxial strain in atomically thin layers. • Email to a friend • More than 25 years since the discovery of superconductivity in strontium ruthanate (SRO), understanding the properties of this material remains as challenging as ever. Researchers now demonstrated that a SRO sample can allow the two energetically degenerate condensates of Cooper-pairs with opposite momentum to segregate in domains, with a domain wall in between where chirality changes. To use the analogy to Moses parting the sea, here the Red Sea would spontaneously part into 'magenta' and 'yellow' seas on either side. • Email to a friend • Breath is one of the main sources of human health parameters that can be used for predicting the state of internal organs. Exhaled breath composition is very complex and the existence of disease marker molecules can be as low as one part per million. That means that using breath for health monitoring purposes requires highly sensitive tools with a recognition ability down to single molecules. Researchers developed a method for fast, on-site and still accurate breath analysis that does not need special preparation of breath samples. The method is based on an electronic nose platform that uses a set of single-walled carbon nanotube sensors deposited on flexible substrates and modified by different semiconducting organic molecules. • Email to a friend • Superconducting materials, which entirely lose their electrical resistance at low temperatures, have become ever more widespread over recent years. Nevertheless, the fascinating phenomenon of superconductivity does not cease to surprise, as the kinds of materials able to superconduct, as well as the mechanisms through which superconductivity emerges, have become increasingly diverse. One of the prime examples is found in the compound 2D material tantalum disulfide, where the critical temperature below which superconductivity appears increases multifold as the crystal is made thinner down to a monolayer. • Email to a friend • Those of us who work in the field of nanoscience know all about the uniqueness of the nanoscale. However, now that use cases for nanotechnology are ramping up across virtually all industry sectors, it's essential to take a step back and remember that few in the business world have experience like ours. In fact, many in the C-suite may be unsure of what nanoscience is or how their businesses could benefit from it. That's a big problem - because these decision makers are not going to support nanotechnology projects that they don't fundamentally understand. We need to rise to the challenge and start helping business leaders appreciate the distinctiveness and enormous potential of this rapidly evolving field. • Email to a friend • |
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