Enhanced Arsenic Detection in Water, Food, Soil

In Journal of Applied Physics, a team of scientists fabricate sensitive nanostructured silver surfaces to detect arsenic, even at very low concentrations. The sensors make use of surface-enhanced Raman spectroscopy: As a molecule containing arsenic adheres to the surface, it’s hit with a laser and the arsenic compound scatters the laser light, creating an identifiable signature. The technique is a departure from existing methods, which are time-consuming, expensive, and not ideally suited to on-site field assays.

Nanopore-Based Sensing Device Explores Neurodegenerative Diseases

In Journal of Applied Physics, researchers present a special silicon nitride nanopore-based sensing device that is designed to provide volume information about tau and tubulin protein molecules and their aggregation states. To create the sensor, the team explored how the proteins change the current and voltage flowing through a nanopore system.

Low-Cost Disease Diagnosis by Mapping Heart Sounds

In the Journal of Applied Physics, researchers develop a method to identify aortic valve dysfunction using complex network analysis that is accurate, simple to use, and low-cost. They used heart sound data to create a complex network of connected points, which was split into sections, and each part was represented with a node. If the sound in two portions was similar, a line was drawn between them. In a healthy heart, the graph showed two distinct clusters of points, with many nodes unconnected. A heart with aortic stenosis contained many more correlations and edges.

Urban Magnetic Fields Reveal Clues about Energy Efficiency, Pollution

In Journal of Applied Physics, researchers from the United States and Germany present a comparative analysis of urban magnetic fields between two U.S. cities: Berkeley, California, and the Brooklyn borough of New York City. They explore what kinds of information can be extracted using data from magnetic field sensors to understand the working of cities and provide insights that may be crucial for preventative studies.

Carbon Fibers Electrical Measurements Pave Way for Lightning Strike Protection Technologies

Carbon fiber reinforced polymer composite structures are important in several industries, yet the electrical behavior of a composite is challenging to measure or predict because of the electrical conductivity of constituent carbon fibers and the composite’s complex hierarchical microstructure. In Journal of Applied Physics, researchers report the first direct measurement of the transverse electrical resistivity of a single carbon fiber. The researchers combined a precise sample preparation with a technique called the van der Pauw method to accomplish this challenging measurement.

Bending Light for Safer Driving; Invisibility Cloaks to Come?

Optical cloaking allows objects to be hidden in plain sight by guiding light around anything placed inside the cloak. While cloaking has been popularized in fiction, researchers in recent years have started realizing cloaks that shield objects from view by controlling the flow of electromagnetic radiation around them. In Journal of Applied Physics, researchers examined recent progress of developing invisibility cloaks that function in natural incoherent light and can be realized using standard optical components.

Understanding the Utility of Plasmas for Medical Applications

Plasma medicine is an emerging field, as plasmas show promise for use in a wide range of therapies from wound healing to cancer treatment, and plasma jets are the main plasma sources typically used in plasma-surface applications. To better understand how plasma jets modify the surfaces of biological tissue, researchers conducted computer simulations of the interaction between an atmospheric pressure plasma jet with a surface that has properties similar to blood serum. They present their analysis in the Journal of Applied Physics.

Energy Harvesting Goes Organic, Gets More Flexible

The race is on to create natural biocompatible piezoelectric materials for energy harvesting, electronic sensing, and stimulating nerves. Researchers decided to explore peptide-based nanotubes, and in the Journal of Applied Physics, they report using a combination of ultraviolet and ozone exposure to generate a wettability difference and an applied field to create horizontally aligned polarization of nanotubes on flexible substrates with interlocking electrodes. The group’s work will enable the use of organic materials more widely.

Spider Silk Can Create Lenses Useful for Biological Imaging

Spider silk is useful for a variety of biomedical applications: It exhibits mechanical properties superior to synthetic fibers for tissue engineering, and it is not toxic or harmful to living cells. One unexpected application for spider silk is its use in the creation of biocompatible lenses for biological imaging applications. Researchers describe the feasibility of creating lenses capitalizing on the properties of natural spider silk material in the Journal of Applied Physics.

Lack of Damage After Secondary Impacts Surprises Researchers

When a material is subjected to a shock or blast wave, damage often forms internally through spall fracture, and research is needed to know how these damaged materials respond to subsequent shock waves. Recent experimentation on spall fracture in metals found that, in certain cases, there was an almost complete lack of damage with only a thin band of altered microstructure observed. In the Journal of Applied Physics, researchers narrowed down exactly why the expected damage was missing.

Determining Effective Magnetic Moment of Multicore Nanoparticles

Most commercial nanoparticles do not possess a single magnetic core but have small magnetic crystals called crystallites. The important question is how these crystallites behave inside a multicore nanoparticle and how they respond to an applied magnetic field. In the Journal of Applied Physics, researchers compare the effective magnetic moments of different multicore nanoparticle systems and shows that they are magnetic-field dependent. The paper’s findings are important for researchers optimizing magnetic nanoparticles for various applications.

Image Analysis Technique Provides Better Understanding of Heart Cell Defects

Many patients with heart disease face limited treatment options. Fortunately, stem cell biology has enabled researchers to produce large numbers of cardiomyocytes, which may be used in advanced drug screens and cell-based therapies. However, current image analysis techniques don’t allow researchers to analyze heterogeneous, multidirectional, striated myofibrils typical of immature cells. In the Journal of Applied Physics, researchers showcase an algorithm that combines gradient methods with fast Fourier transforms to quantify myofibril structures in heart cells with considerable accuracy.

SDSC Supercomputer Simulations Aid in Solving Boron Carbide Mystery

Building upon decades of research on how to make boron carbide even more efficient, an engineering team at the University of Florida (UF) has been conducting simulations using SDSC’s Comet supercomputer to better understand the nanoscale level deformation mechanisms of this important material.

Insects’ Drag-Based Flight Mechanism Could Improve Tiny Flying Robots

Thrips don’t rely on lift in order to fly. Instead, the tiny insects rely on a drag-based flight mechanism, keeping themselves afloat in airflow velocities with a large ratio of force to wing size. In a study published in this week’s Journal of Applied Physics, researchers performed the first test of the drag force on a thrip’s wing under constant airflow in a bench-top wind tunnel. Drawing from experience in microfabrication and nanomechanics, they created an experiment in which a thrip’s wing was glued to a self-sensing microcantilever.

Future of LEDs Gets Boost from Verification of Localization States Within Indium Gallium Nitride Quantum Wells

LEDs made of indium gallium nitride provide better luminescence efficiency than many of the other materials used to create blue and green LEDs, but a big challenge of working with InGaN is its known dislocation density defects that make it difficult to understand its emission properties.