Electroantennography-based Bio-hybrid Odor-detecting Drone using Silkmoth Antennae for Odor Source Localization.

Small drones with chemical or biosensor devices that can detect airborne odorant molecules have attracted considerable attention owing to their applicability in environmental and security monitoring and search-and-rescue operations. Small drones with commercial metal-oxide-semiconductor (MOX) gas sensors have been developed for odor source localization; however, their real-time-odor-detection performance has proven inadequate. However, biosensing technologies based on insect olfactory systems exhibit relatively high sensitivity, selectivity, and real-time response with respect to odorant molecules compared to commercial MOX gas sensors.

Surface Plasmon Resonance (SPR)- and Localized SPR (LSPR)-Based Virus Sensing Systems: Optical Vibration of Nano- and Micro-Metallic Materials for the Development of Next-Generation Virus Detection Technology.

The global damage that a widespread viral infection can cause is evident from the ongoing COVID-19 pandemic. The importance of virus detection to prevent the spread of viruses has been reaffirmed by the pandemic and the associated social and economic damage. Surface plasmon resonance (SPR) in microscale and localized SPR (LSPR) in nanoscale virus sensing systems are thought to be useful as next-generation detection methods.

Preliminary system of rapid analysis of blood retinol level in cattle.

Control of blood retinol levels in cattle during fattening is important in the production of marbled beef. However, it is difficult to easily measure the blood retinol concentration in the field. In this study, we attempted to develop an analysis method that does not require blood cell separation and uses a compact fluorescence analyzer that can be carried around as a preliminary system for measuring blood retinol concentration in the field.

Mask-Type Sensor for Pulse Wave and Respiration Measurements and Eye Blink Detection.

This paper reports on a mask-type sensor for simultaneous pulse wave and respiration measurements and eye blink detection that uses only one sensing element. In the proposed sensor, a flexible air bag-shaped chamber whose inner pressure change can be measured by a microelectromechanical system-based piezoresistive cantilever was used as the sensing element. The air bag-shaped chamber is fabricated by wrapping a sponge pad with plastic film and polyimide tape.

System for Visualizing Surface Potential Distribution to Eliminate Electrostatic Charge.

A mixture of positive and negative static charges exists in the same plane on an insulator surface, and this can cause production quality problems at manufacturing sites. This study developed a system with a vibration array sensor to rapidly measure the surface potential distribution of an object in a non-contact and non-destructive manner and with a high spatial resolution of 1 mm. The measurement accuracy differed greatly depending on the scanning speed of the array sensor, and an optimum scanning speed of 10 mm/s enabled rapid measurements (within <3 s) of the surface potential distribution of a charged insulator (area of 30 mm × 30 mm) with an accuracy of 15%.

Significant Enhancement of Piezoelectric Response in AlN by Yb Addition.

This study employs first-principles calculations to investigate how introducing Yb into aluminum nitride (AlN) leads to a large enhancement in the material's piezoelectric response (). The maximum is calculated to be over 100 pC/N, which is 20 times higher than that of AlN. One reason for such a significant improvement in is the elastic-softening effect, which is indicated by a decrease in the elastic constant, .

In vitro survival kinetics of microfluidic-sorted bovine spermatozoa.

Background: The isolation and characterization of sperm subpopulations that can achieve fertilization is a major challenge of assisted reproduction methods. We focused on the microfluidic sperm sorter as a novel tool for collecting highly motile spermatozoa from heterogeneous semen samples.

Objectives: This study primarily aims to obtain baseline information on sorted spermatozoa according to its characteristics and in vitro life span.

Real-time, non-invasive thrombus detection in an extracorporeal circuit using micro-optical thrombus sensors.

Introduction: Real-time, non-invasive monitoring of thrombus formation in extracorporeal circuits has yet to be achieved. To address the challenges of conventional optical thrombus detection methods requiring large devices that limit detection capacity, we developed a micro-optical thrombus sensor.

Methods: The proposed micro-optical thrombus sensor can detect the intensity of light scattered by blood at wavelengths of 660 and 855 nm.

Laser-Induced Phosphorus-Doped Conductive Layer Formation on Single-Crystal Diamond Surfaces.

A laser-induced doping method was employed to incorporate phosphorus into an insulating monocrystalline diamond at ambient temperature and pressure conditions. Pulsed laser beams with nanosecond duration (20 ns) were irradiated on the diamond substrate immersed in a phosphoric acid liquid, in turns, and a thin conductive layer was formed on its surface. Phosphorus incorporation in the depth range of 40-50 nm below the irradiated surface was confirmed by secondary ion mass spectroscopy (SIMS).

Toughness and Durability of Interfaces in Dissimilar Adhesive Joints of Aluminum and Carbon-Fiber-Reinforced Thermoplastics.

The toughness and the durability under a high humidity condition of the interfaces in dissimilar adhesive joints of carbon-fiber-reinforced thermoplastic with a polyamide-6 matrix and Al alloy were evaluated by two test methods, in which a tensile opening load was applied to the specimens to cleave the interfaces apart in two different ways. In the double cantilever beam (DCB) test, the specimens were continuously pulled apart at a constant velocity, while in the wedge test, the specimens are pulled apart at a constant displacement. The crack growth along the interface in the DCB test was dynamically monitored with the assistance of mechanoluminescence for the accurate detection of the phenomena at the crack tip.

Electrical Characterization of a Double-Layered Conductive Pattern with Different Crack Configurations for Durable E-Textiles.

For the conductive patterns of electronic textiles (e-textiles), it is still challenging to maintain low electrical resistance, even under large or cyclic tensile deformation. This study investigated a double-layered pattern with different crack configurations as a possible solution. Patterns with single crack growth exhibit a low initial resistance and resistance change rate.

A Simple, Low Cost, Sensitive, and Portable Electrochemical Immunochromatography Sensing Device to Measure Estrone-3-Sulfate.

In livestock production, point-of-care testing (POCT) technology that enables easy on-site analysis of sex hormones is desired to improve reproductive efficiency. In this context, low-molecular-weight endogenous steroids are particularly important for perinatal management. Therefore, we attempted to use a simple method that combines electrochemical techniques with immunochromatography to measure estrone-3-sulfate (ES), one of the low-molecular-weight endogenous steroids that is an estrogen ester.

Capillary-condensed water in nonporous nanoparticle films evaluated by impedance analysis for nanoparticle devices.

We study capillary-condensed water in nonporous nanoparticle films and evaluate its effect on impedance analysis for practical nanoparticle devices. Nanoparticle-based electronic/optoelectronic devices have been intensively studied for applications in ambient air. Non-sintered nanoparticle films have porous structures and a vapor phase of water molecules condenses in nanopores between nanoparticles at a lower vapor pressure.

Quick assessment of influenza a virus infectivity with a long-range reverse-transcription quantitative polymerase chain reaction assay.

Background: The polymerase chain reaction (PCR) is commonly used to detect viral pathogens because of its high sensitivity and specificity. However, conventional PCR methods cannot determine virus infectivity. Virus infectivity is conventionally examined with methods such as the plaque assay, even though such assays require several days.

An on-demand bench-top fabrication process for fluidic chips based on cross-diffusion through photopolymerization.

In this paper, we propose a novel approach to fabricate fluidic chips. The method utilizes molecular cross-diffusion, induced by photopolymerization under ultraviolet (UV) irradiation in a channel pattern, to form the channel structures. During channel structure formation, the photopolymer layer still contains many uncured molecules.

Nonporous Inorganic Nanoparticle-Based Humidity Sensor: Evaluation of Humidity Hysteresis and Response Time.

Fast-response humidity sensors using nanomaterials are attractive and have been intensively studied. Among the various nanomaterials, nonporous inorganic nanoparticles are suitable for use in humidity sensitive films for sensors. Here, we focus on a nonporous inorganic nanoparticle film and investigate a humidity sensor using the film.

Technical note: Calving prediction in dairy cattle based on continuous measurements of ventral tail base skin temperature using supervised machine learning.

In this study, we developed a calving prediction model based on continuous measurements of ventral tail base skin temperature (ST) with supervised machine learning and evaluated the predictive ability of the model in 2 dairy farms with distinct cattle management practices. The ST data were collected at 2- or 10-min intervals from 105 and 33 pregnant cattle (mean ± standard deviation: 2.2 ± 1.

Electromechanically Active As-Electrospun Polystyrene Fiber Mat: Significantly High Quasistatic/Dynamic Electromechanical Response and Theoretical Modeling.

Flexible and lightweight pressure sensors have attracted tremendous attention as a promising component of wearable biological motion sensors and artificial electronic skins. Here, the electromechanical response of as-electrospun fiber mats composed of a commodity polymer, atactic polystyrene, which can be applied in low-cost/large-area, flexible, and lightweight pressure sensors is demonstrated. The fiber mat demonstrates a significantly high apparent converse piezoelectric constant of >30 000 pm V under static measurement and ≈13 000 pm V even at a high frequency of 1 kHz.

Bubble entrapment during the recoil of an impacting droplet.

When a droplet impacts a (super-)hydrophobic surface, there is a range of Weber numbers within which bubble entrapment will occur during droplet recoil due to closure of the air cavity developed when the droplet spreads out during the impact. In this study, we studied bubble entrapment using a microelectromechanical system (MEMS)-based acoustic sensor fabricated on a substrate. We found that bubble entrapment is followed by an acoustic vibration that can be detected by the sensor.

Voltage Contrast in Scanning Electron Microscopy to Distinguish Conducting Ag Nanowire Networks from Nonconducting Ag Nanowire Networks.

A study of the electrical properties of metallic nanowires requires a clear analysis of conductive networks. In this study, we demonstrated that the conducting networks of Ag nanowires (AgNW) could be visually observed by examination of the voltage contrast of the scanning electron microscopy (SEM) images, which was caused by the differences in the degrees of charging of AgNWs. When AgNWs dispersed on a quartz glass were irradiated by primary electrons, the substrate became negatively charged.

Sensitive Detection of C-Reactive Protein by One-Step Method Based on a Waveguide-Mode Sensor.

One-step biosensing methods enable the quick and simplified detection of biological substances. In this study, we developed a sensitive one-step method on the basis of a waveguide-mode sensor, which is an optical sensor utilizing waveguide-mode resonance and evanescent light. Streptavidin-conjugated and gold-nanoparticle-conjugated antibodies were reacted with a target substance and applied onto a biotinylated sensing plate.

Resistance Reduction of Conductive Patterns Printed on Textile by Curing Shrinkage of Passivation Layers.

Directly printing conductive ink on textiles is simple and compatible with the conventional electronics manufacturing process. However, the conductive patterns thus formed often show high initial resistance and significant resistance increase due to tensile deformation. Achieving conductive patterns with low initial resistance and reduced deformation-induced resistance increase is a significant challenge in the field of electronic textiles (e-textiles).

Micro-transfer patterning of dense nanoparticle layers: roles of rheology, adhesion and fracture in transfer dynamics.

Liquid inks deposited on substrates undergo spreading, coalescence, dewetting and subsequent drying kinetics, which limit the controllability of the cross-sectional shape and resolution of the printed patterns. By contrast, when the ink layers are previously semidried (highly-concentrated) and patterned on a polydimethylsiloxane sheet, single-micrometer features are resolved. Here we present the rheological, fracture and adhesive properties of semidried nanoparticle dispersion ink layers, which optimize the patterning of reverse offset printing with 5 μm spatial resolution.

Decimating Spatial Frequency Components in Periodically Modulated Nanoscale Surface Structures for Sensing of Ambient Refractive Index Changes.

In our previous study, we developed an array of unique porous structures (an array of barnacle-like porous structures) to apply to biosensing chips. The porous structure was formed by an internal swelling phenomenon of a polystyrene colloidal particle monolayer, which was surrounded by a poly(vinyl alcohol) layer, for the duration of the monolayer's immersion in a toluene bath. Barnacle-like porous structures were formed when polystyrene particles that had rapidly swelled broke the outer layer around the top of the particles.

Effect of Agitation Method on the Nanosized Degradation of Polystyrene Microplastics Dispersed in Water.

Reports of marine organisms ingesting microplastics-formed from large plastic litter drifting in the marine environment by mechanical forces such as waves and photochemical processes initiated by sunlight, particularly ultraviolet rays-are increasing. However, the degradation process from microplastics to nanoplastics that are easily consumed by plankton located in the lower part of the food chain is not clear. Therefore, 200 nm diameter polystyrene (PS) latex particles-nanoparticle tracking analysis (NTA) calibration particles-dispersed in ultrapure deionized water were subjected to three types of agitation: rotation mixing, shaking, and flowing in addition to standing without agitation, and the physical degradation caused by agitation for 1 week at room temperature (23 °C) was evaluated.