Researchers develop nanotechnology for creating wafer-scale nanoparticle monolayers in seconds

Phys.org   May 7, 2024 Underwater adhesion processes have faced challenges to uniformly transfer nanoparticles into a monolayer, particularly those below 100 nm in size, over large areas. Researchers in South Korea have developed a scalable “one-shot” self-limiting nanoparticle transfer technique, enabling the efficient transport of nanoparticles from water in microscopic volumes to an entire 2-inch wafer in a remarkably short time of 10 seconds to reach near-maximal surface coverage in a 2D mono-layered fashion. They used proton engineering in electrostatic assembly which accelerated the diffusion of nanoparticles resulting in a hundredfold faster coating speed than the previously reported results in […]

Deceptive daisy’s ability to create fake flies explained

Science Daily  March 23, 2023 Gene co-option, the redeployment of an existing gene in an unrelated developmental context, is an important mechanism underlying the evolution of morphological novelty. In most cases novel traits emerged by co-option of a single gene or genetic network. An international team of researchers (UK, South Africa) has shown that the integration of multiple co-opted genetic elements facilitated the rapid evolution of complex petal spots that mimic female bee-fly pollinators in the sexually deceptive South African daisy. They explained that co-option of iron homeostasis genes altered petal spot pigmentation, producing a color similar to that of […]

Biomimetic dual-color domes programmable for encryption

Nanowerk  September 15, 2022 Spots with dual structural colors on the skin of some organisms in nature are of interest due to the unique function of their dye-free colors. However, imitation of them requires complicated manufacturing processes, expensive equipment, and multiple predesigned building blocks. Researchers in Hong Kong have developed a one-pot strategy based on the phase-separation-assisted nonuniform self-assembly of monosized silica nanoparticles to construct domes with dual structural colors. In drying poly(ethylene glycol)-dextran-based (PEG-DEX) droplets, monosized nanoparticles distributed nonuniformly in two compartments due to the droplet inner flow and different nanoparticle compatibility with the two phases. The dome colors […]

Nanoclusters self-organize into centimeter-scale hierarchical assemblies

Phys.org  April 22, 2022 An international team of researchers (USA – Cornell University, Rochester Institute of Technology, Canada) has created synthetic nanoclusters from an organic–inorganic mesophase composed of monodisperse Cd37S18 magic-size cluster building blocks. The process produced “magic-size clusters” of 57 atoms, about 1.5 nanometers in length. Each of these nanoparticles had a shell of ligands that could interact with each other in such a way that they formed filaments several microns long and hundreds of nanometers wide. The filaments were periodically decorated with the magic-size clusters with perfect spacing between them. Enhanced patterning was achieved by controlling processing conditions, […]

Insect wings inspire new ways to fight superbugs

EurekAlert  August 18, 2020 New anti-bacterial surfaces are being developed, featuring different nanopatterns that mimic the deadly action of cicadas and dragonflies’ wings. In a review article an international team of researchers (Australia, Spain, USA – Ohio State University, UK) has detailed exactly how these patterns destroy bacteria – stretching, slicing, or tearing them apart. They point out that different species have wings that are better at killing some bacteria than others, the wing surfaces have different density, height, and diameter of the nanopillars. The nanostructured surfaces could be used in medical or industrial applications…read more. TECHNICAL ARTICLE

Nature provides inspiration for researchers developing selective membranes

Nanowerk  July 23, 2020 According to a team of researchers in the US (Yale University, Lawrence Livermore National Laboratory, UC Merced) in the future membranes may be engineered with the ability to select which substances they allow through, even to the point of distinguishing between very similar ions such as potassium and sodium. They introduce the challenges of state-of-the-art membranes with subnanometre pores to achieve high selectivity between solutes, analyse experimental and theoretical literature to discuss the molecular-level mechanisms that contribute to energy barriers for solute transport through subnanometre pores. They conclude by providing principles and guidelines for designing next-generation […]

Leaf-inspired surface prevents frost formation

Science Daily  March 10, 2020 Based on their fundamental understanding of discontinuous frost patterns found on the leaf vein structure on the scale of millimeters, researchers at Northwestern University elucidated the thermodynamic correlation between the frost-free area and two major surface system parameters—macroscopic surface geometry and ambient humidity. This systematic study on the frost formation mechanism allowed them to demonstrate a ∼50% of frost coverage even for superhydrophilic surfaces and provides a quantitative guideline for further reducing frost coverage. The finding could help decrease the amount of energy needed for de-frosting and could potentially result in fewer canceled flights, which […]

To make ultra-black materials that won’t weigh things down, consider the butterfly

Science Daily  March 10, 2020 Recently, it has been shown that animals such as jumping spiders, birds, and butterflies have evolved ultra-black coloration comparable to the blackest synthetic materials. Researchers at Duke University examined a phylogenetically diverse set of butterflies and found considerable interspecific variation in the geometry of the holes in the structures reduce reflectance up to 16-fold. They produce ultra-black by creating a sparse material with high surface area to increase absorption and minimize surface reflection. They hypothesized that butterflies use ultra-black to increase the contrast of color signals. The findings could help engineers design thinner ultra-black coatings […]

Shining a new light on biomimetic materials

Phys.org  February 25, 2020 Self-trapped light beams hold potential for optical interconnects, applications in image transmission, rerouting light, logic gates for computing and for the next-generation light-guiding-light signal processing. However, self-trapping suffers from either the need for large incident beam power and loss of beam interactions at large distances, or it is slow and irreversible. An international team of researchers (Canada, USA – Harvard University, University of Pittsburgh) has shown that rapidly and repeatably switchable self-trapped laser beams with remote communication capabilities can be elicited at exceptionally small intensities in a pliant, processable hydrogel functionalized with a chromophore. According to […]

What do dragonflies teach us about missile defense?

Science Daily  July 24, 2019 Researchers at Sandia National Laboratory are examining whether dragonfly-inspired computing could improve missile defense systems, which have the similar task of intercepting an object in flight, by making on-board computers smaller without sacrificing speed or accuracy. In recent computer simulations, faux dragonflies in a simplified virtual environment successfully caught their prey using computer algorithms designed to mimic the way a dragonfly processes visual information while hunting. Missile defense systems rely on established intercept techniques that are computation heavy. The dragonfly model could potentially, shrink the size, weight and power needs of onboard computers. It may […]