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The paper contains the results of a recognition technique based on the comparison of statistical and stochastic characteristics of the wavelet coefficients of energy density describing the emission energy of a nanocrystal with a quantum dot according to the Brus equation for traditional and perspective materials for quantum dots (CdSe, GaAs, CdTe, PbS) used in optoelectronic engineering and technology, in order to analyze their characteristics. [ABSTRACT FROM AUTHOR]

The recently discovered hexagonal wurtzite phase of several III-V nanowires opens up strong opportunity to engineer optoelectronic and transport properties of III-V materials. Herein, we explore the dynamical and dielectric properties of cubic (3C) and wurtzite (2H) III-V compounds (AlP, AlAs, AlSb, GaP,GaAs, GaSb, InP, InAs, and InSb). For cubic III-V compounds, our calculated phonon frequencies agree well with neutron diffraction and Raman-scattering measurements. In the case of 2H III-V materials, our calculated phonon modes at the zone-center G point are in distinguished agreement with available Raman-spectroscopy measurements of wurtzite GaAs, InP, GaP, and InAs nanowires. Particularly, the "fingerprint" of the wurtzite phase, which is our predicted E2(high) phonon mode, at 261cm-1(GaAs), 308cm-1(InP), 358cm-1(GaP), and 214cm-1(InAs) matches perfectly the respective Raman values of 258cm-1, 306.4cm-1, 353cm-1, and 213.7cm-1 for GaAs, InP, GaP, and InAs. Moreover, the dynamic charges and high-frequency dielectric constants are predicted for III-V materials in both cubic (3C) and hexagonal (2H) crystal polytypes. It is found that the dielectric properties of InAs and InSb contrast markedly from those of other 2H III-V compounds. Furthermore, InAs and InSb evidence relative strong anisotropy in their dielectric constants and Born effective charges, whereas GaP evinces the higher Born effective charge anisotropy of 2H III-V compounds. [ABSTRACT FROM AUTHOR]

The paper analyses the operation of different types of electronic colour sensors based on the light spectrum analysis. The application goal was to detect the type of the airport lamp based on differences in colour components of the light emitted by luminaires with specific spectral characteristics. Recognition of airport lamps is based on the analysis of the light spectrum. Proposed solution allows for an automatic software selection of appropriate conversion factors and comparison with specific standards necessary for this type of measurements. Various types of sensors were discussed and the AS7262 sensor was examined in detail. The colour sensor and the light intensity sensor were used in the mobile control device for examining elevated airport lamps and in the measurement platform for quality testing of embedded airport lamps. Two additional aspects were investigated: 1) influence of an additional acrylic glass cover; 2) distance between airport lamps and the spectrum sensor. [ABSTRACT FROM AUTHOR]

Abstract A rapid, single-point method for colorimetric creatinine determination has been developed as an alternative for a well-established Jaffé assay, which lacks analytical specificity. 3,5-dinitrobenzoic acid was employed in an alkaline environment as a chromophore instead of picric acid. Apart from the spectrophotometer, a simple optoelectronic detector was applied as an alternative detection method. The conditions of the reaction were optimized to provide satisfactory analytical parameters. The linear ranges of the proposed assays were 40–4000 and 10–300 µmol L−1 of creatinine for conventional spectrophotometry and a PEDD detector, respectively. A broad spectrum of potential interferents was examined. The presence of compounds such as glucose, urea or uric acid was the source of a significantly smaller bias in the examined method than in the case of the Jaffé method variants. The presented method was validated with the use of 10 human urine samples with the creatinine level determined by the recommended method. Two-tail paired Student's t-tests with 9 degrees of freedom at the 95% confidence level showed the agreement between the proposed and the reference methods. Graphical abstract fx1 Highlights • A rapid, single-point method of creatinine determination has been developed. • The method exhibits fewer interferences than well-established Jaffé assay. • The method was validated using human urine real samples. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new touch-trigger probe with high precision and a large permissible measurement range. A wedge prism was used in the sensing unit to achieve 3D detection using only one optoelectronic sensor. The measurement range was expanded from ±8 µm to ±14 µm through the new optical structure. The probe has uniform stiffness and uniform sensitivity. Some experiments were performed to investigate the performance of the probe. It was found that the probe has a resolution of 10 nm and a repeatability of less than 9.1 nm. The applicability of the probe was also verified. [ABSTRACT FROM AUTHOR]

The theoretical approach to investigate the frequency pulling phenomenon, when the optoelectronic oscillator is injected by a weak radio frequency (RF) signal, is presented. The differential equation for the phase perturbation is derived. The analytical expressions of the phase-difference after locking and lock-range are derived here. Here, we also study the influence of the injection RF signal on the beat frequency, average frequency, and actual pull-in frequency. Also, the dependency of beat frequency and average frequency on injection frequency is studied here. All the analytical expressions clearly reveal the frequency pulling phenomenon from fast-beat state through quasi-locked state to locked state. Simulation results are also given in support of the theoretical study. [ABSTRACT FROM AUTHOR]

We present a novel bimodal optoelectronic sensor based on Fresnel lenses and the associated stereo-recording device that records the wingbeat event of an insect in flight as backscattered and extinction light. We investigate the complementary information of these two sources of biometric evidence and we finally embed part of this technology in an electronic e-trap for fruit flies. The e-trap examines the spectral content of the wingbeat of the insect flying in and reports wirelessly counts and species identity. We design our devices so that they are optimized in terms of detection accuracy and power consumption, but above all, we ensure that they are affordable. Our aim is to make more widespread the use of electronic insect traps that report in virtually real time the level of the pest population from the field straight to a human controlled agency. We have the vision to establish remote automated monitoring for all insects of economic and hygienic importance at large spatial scales, using their wingbeat as biometric evidence. To this end, we provide open access to the implementation details, recordings, and classification code we developed. [ABSTRACT FROM AUTHOR]

A well nanocrystalline structured tin substituted nickel ferrite thin film was prepared by chemical co-precipitation method. XRD analysis reveals the average crystallite size as 51 nm and most preferential peak (311) affirms the formation of tin substituted nickel ferrite. The SEM morphology shows the large number of active sites. FT-IR analysis reveals the general nature of ferrite materials. TEM analysis shows the inhomogeneous distribution of particles. Also, the SAED pattern exhibits the polycrystalline nature. From UV analysis, it was observed that material has absorption in visible region at ∼201 nm. Humidity sensing analysis reveals that material has average sensitivity is 2.08 MΩ/%RH and excellent reproducibility with response and recovery times of 44 and 180 s respectively. [ABSTRACT FROM AUTHOR]

The adsorption of polymers on smooth or atomistically flat substrates has been a topic of study for decades, and such systems are well-characterized. However, there is little knowledge of the complex interfaces created by adsorption on heterogeneous surfaces: these are fundamental to numerous scientific and industrial systems, including organic optoelectronics, polymer–matrix composites, protein attachment, biomimetics, lubrication, and catalysis. Focusing on physical inhomogeneities, this paper presents an overview of the field of polymer adsorption on rough surfaces, and seeks to elucidate some of the relevant molecular mechanisms. Monte Carlo simulations are employed to study freely rotating chains adjacent to self-affine substrates, exploring the influence of surface fractal dimension and amplitude. The adsorbed polymers are characterized by density profiles and chain topologies evaluated parallel and perpendicular to the nominal surface. Our results reveal chain attachment and film structure can be controlled solely by manipulating entropic factors such as surface physical heterogeneities and adsorbate molecular weight distributions. [ABSTRACT FROM AUTHOR]

The degradation of methyl-ammonium lead iodide (MAPbI 3 ) upon exposure to air is a potentially limiting effect for large scale MAPbI 3 photovoltaic production. Here, we report a systematic study on effects of air-exposure on the structural and optical properties of MAPbI 3 thin films. The X-ray diffraction studies indicate a shrinking volume of MAPbI 3 upon air-exposure as the material decomposes back to its precursors, methyl amine (CH 3 NH 2 ) and lead iodide (PbI 2 ). However, the photoluminescence (PL) yield and carrier lifetime measured with time-resolved photoluminescence, show an increasing trend upon air-exposure. These phenomena can be explained by self-passivation of MAPbI 3 grains by PbI 2 layer that reduces the number of non-radiative recombination centres at the grain boundaries. However, this process is not self-limiting and it eventually leads to a film that has completely reverted back to its precursor state. It is shown that this conversion of MAPbI 3 film back to its precursors is also accelerated by exposure to laser illumination. Furthermore, we report unusual variation of PL intensity on a shorter time scale of a few seconds in all the films used for the experiment. The variations are found to follow different trends in the encapsulated samples as compared to the un-encapsulated samples. We propose that the decomposition followed by the ionic diffusion through film is responsible for such unusual behaviours. [ABSTRACT FROM AUTHOR]

This paper presents the description of a cyber-physical system embedded on an FPGA for 3D measurement in structural health monitoring tasks. The implementation technique and performance evaluation demonstrate the contribution of this paper to the mathematical fundamentals adaptation of an on-site rotatory scanning system to a cyber-physical system. In particular, it is described in detail the design of a virtual angle measurement soft sensing technique based on the information conversion of an optoelectronic signal provided by a rotatory scanning system through an FPGA. Behaving the FPGA as the sensor controller and the actuator in the scanning system. Using the measurement of angles through the proposed embedded system, it can be calculated the coordinates and displacement of specific indicators distributed over a structure under observation. Providing online data exchange from on-site measurement to a remote computational station for real-time or posteriorly data analysis. [ABSTRACT FROM AUTHOR]

In recent years, nanowires have been shown to exhibit high photosensitivities, and, therefore are of interest in a variety of optoelectronic applications, for example, colour-sensitive photodetectors. In this study, we fabricated two-terminal PbS, In 2 S 3 , CdS and ZnSe single-nanowire photoresistor devices and tested applicability of these materials under the same conditions for colour-sensitive (405 nm, 532 nm and 660 nm) light detection. Nanowires were grown via atmospheric pressure chemical vapour transport method, their structure and morphology were characterized by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), and optical properties were investigated with photoluminescence (PL) measurements. Single-nanowire photoresistors were fabricated via in situ nanomanipulations inside SEM, using focused ion beam (FIB) cutting and electron-beam-assisted platinum welding; their current-voltage characteristics and photoresponse values were measured. Applicability of the tested nanowire materials for colour-sensitive light detection is discussed. [ABSTRACT FROM AUTHOR]

In this paper, the design and the implementation of a force sensor based on a commercial optoelectronic component called light fork and characterized by the simple construction process is presented. The proposed sensor implementation is designed to measures the force applied by a cable-based actuation by detecting the deformation of a properly designed compliant structure integrated into the actuation module. Despite this, the design method here presented allows to adapt the sensor to a large set of robotic applications, thanks to its simplicity in the construction and low cost. The main advantages of the proposed sensor consist in the use of a very compact commercial optoelectronic component, called light fork, as sensing element. This solution allows a very simple assembly procedure together with a good sensor response in terms of sensitivity, linearity and noise rejection to be achieved using an extremely simple electronics, thereby obtaining in this way a reliable and very cheap sensor that can be easily integrated in actuation modules for robots and can easily adapted to a wide application set. The paper presents the basic sensor working principle and the compliant frame design. An analytic model of the compliant frame deformation is proposed and verified both by finite element analysis and by experimental measures performed on four different sensor specimens manufactured by 3D printing and CNC milling, and the results have been compared. Moreover, the sensor specimens calibration and the experimental validation have been performed both in static and dynamic conditions. [ABSTRACT FROM AUTHOR]

Features in the process of monitoring the diameter of tension springs and other spiral-like bodies in the course of their manufacture are considered and the selection of an optoelectronic method of measuring the diameter of a spring is evaluated. Structural data and the characteristics of a newly designed sensor that satisfies the technological requirements are presented. A technique for calibrating the sensor is proposed and implemented. Testing of the sensor in an actual production process is performed. Satisfactory results from a comparison of the estimators of the diameter performed by the optoelectronic technique and by indirect techniques are obtained. [ABSTRACT FROM AUTHOR]

The electronical and optical properties of CdGa2S4 under high pressures were studied using the full potential linearized augmented plane wave (FP-LAPW) method within the GGA and mBJ exchange correlation potentials from 0.0 to 16.92 GPa. The obtained results show that the lattice constants, bandgap values, and optoelectronic properties are sensitive to applied external pressures. The mBJ results indicate that the bandgap increases and the static dielectric constants decrease with increasing the pressure. The two none zero dielectric tensor components show considerable anisotropy between the perpendicular and parallel components. The maximum absorption for x direction in all pressures takes place in vacuum UV region. Also, the plasma frequency shifts to the higher energies with increasing the pressure for application in optical devices. The calculated results by mBJ are in close agreement with the experimental values. [ABSTRACT FROM AUTHOR]

A characterization environment was built to verify the timing characteristics of a single photon avalanche diode (SPAD) array designed for time-gated Raman spectroscopy. The characterization was applied to a $256 \times 16$ SPAD array that employed an on-chip time-to-digital converter (TDC) with a 50–100-ps resolution for time resolving. The timing skew and the time window homogeneity across the array were resolved, moving the time-resolving windows over an optical pulse by picosecond-level delay steps. A typical one 160-ps skew across the array was measured. The TDC time bins had average sizes of 33–144 ps while their deviation across the array was 8–12 ps. The method is applicable to multidetector time-correlated single photon counting systems that can finely adjust the delay between the optical pulse and the reference signal. [ABSTRACT FROM PUBLISHER]

Wound care technologies need to adapt in order to cope with the growing socio-economic burden of chronic wounds. Non-invasive analytical systems which monitor important wound status biomarkers such as pH of wound fluid, are needed. In this work, a wireless smart bandage for optical determination of pH, as an indicator of wound status, is demonstrated and characterised. The bandage is constructed by immobilising cellulose particles, covalently modified with a pH indicator dye, within a biocompatible hydrogel. Thin layers of the pH sensitive hydrogel are cast onto a conventional dressing and interfaced to a wireless platform via a miniaturised optoelectronic probe. The smart bandage can detect pH changes in the physiologically relevant range with high accuracy and precision, and communicate this information with an external readout unit using radio-frequency identification (RFID). The new system could provide insight into temporal changes in wound status in a convenient and non-invasive manner, and prompt an appropriate response from a healthcare provider. [ABSTRACT FROM AUTHOR]

The concept of remote insect surveillance at large spatial scales for many serious insect pests of agricultural and medical importance has been introduced in a series of our papers. We augment typical, low-cost plastic traps for many insect pests with the necessary optoelectronic sensors to guard the entrance of the trap to detect, time-stamp, GPS tag, and--in relevant cases--identify the species of the incoming insect from their wingbeat. For every important crop pest, there are monitoring protocols to be followed to decide when to initiate a treatment procedure before a serious infestation occurs. Monitoring protocols are mainly based on specifically designed insect traps. Traditional insect monitoring suffers in that the scope of such monitoring: is curtailed by its cost, requires intensive labor, is time consuming, and an expert is often needed for sufficient accuracy which can sometimes raise safety issues for humans. These disadvantages reduce the extent to which manual insect monitoring is applied and therefore its accuracy, which finally results in significant crop loss due to damage caused by pests. With the term 'surveillance' we intend to push the monitoring idea to unprecedented levels of information extraction regarding the presence, time-stamping detection events, species identification, and population density of targeted insect pests. Insect counts, as well as environmental parameters that correlate with insects' population development, are wirelessly transmitted to the central monitoring agency in real time and are visualized and streamed to statistical methods to assist enforcement of security control to insect pests. In this work, we emphasize how the traps can be self-organized in networks that collectively report data at local, regional, country, continental, and global scales using the emerging technology of the Internet of Things (IoT). This research is necessarily interdisciplinary and falls at the intersection of entomology, optoelectronic engineering, data-science, and crop science and encompasses the design and implementation of low-cost, low-power technology to help reduce the extent of quantitative and qualitative crop losses by many of the most significant agricultural pests. We argue that smart traps communicating through IoT to report in real-time the level of the pest population from the field straight to a human controlled agency can, in the very near future, have a profound impact on the decision-making process in crop protection and will be disruptive of existing manual practices. In the present study, three cases are investigated: monitoring Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) using (a) Picusan and (b) Lindgren trap; and (c) monitoring various stored grain beetle pests using the stored-grain pitfall trap. Our approach is very accurate, reaching 98-99% accuracy on automatic counts compared with real detected numbers of insects in each type of trap. [ABSTRACT FROM AUTHOR]

Controlling size and shape of hybrid nanostructures is technologically important because of the strong effect of nanostructure dimension and morphology on optoelectronic, biosensors and catalytic properties. Here, we have demonstrated a simple strategy for simultaneous control of morphology, defect engineering and photocatalytic activities of reduced graphene oxide:zinc oxide (rGO:ZnO) hybrid nanostructures which were prepared by using low frequency (42 kHz) ultrasound. By varying the solvents, the morphology of ZnO gradually evolved from spherical shape to a star like nature and the ZnO nanoparticles decorated on reduced graphene oxide were clearly observed in the TEM analysis. Absorption, photoluminescence, Raman and FTIR spectra clearly indicated the formation of rGO:ZnO hybrid nanostructures. Thermal analysis revealed that the hybrid nanostructures exhibited a good thermal stability. The synergistic integration of the unique morphology and size imparts the rGO:ZnO hybrid nanostructures with remarkably enhanced photocatalytic efficiency when compared with bare ZnO. The enhanced photocatalytic behaviour of the rGO:ZnO composite has been discussed in details herein. Simple and facile synthesis route demonstrated the potential for the utilization of rGO:ZnO hybrid nanostructures with unique properties for environmental engineering applications. [ABSTRACT FROM AUTHOR]

Smart touch sensors are used in many applications, such as the iPhone and some smart home systems. Recent touch sensors perform well in consumer electrical devices; however, there are some drawbacks. For example, most touch sensors have low accuracy for detecting human movements. Many require significant power and have a fixed shape. We propose a flexible, highly accurate, and energy-conserving touch sensor. Our primary contributions are as follows: (1) an energy-conserving touch sensor is developed and tested experimentally; (2) a flexible and arbitrarily shaped touch sensor is designed; and (3) the manufacturing cost is very low and up to 200 touch sensors can be connected to the system. As a result, this energy-conserving touch sensor can be fabricated using common manufacturing processes for consumer electronic devices. [ABSTRACT FROM AUTHOR]

Different skin pigments among various ethnic group people have an impact on spectrometric illumination on skin surface. To effectively capture photoplethysmographic (PPG) signals, a multi-wavelength opto-electronic patch sensor (OEPS) together with a schematic architecture of electronics were developed to overcome the drawback of present PPG sensor. To perform a better in vivo physiological measurement against skin pigments, optimal illuminations in OEPS, whose wavelength is compatible with a specific skin type, were optimized to capture a reliable physiological sign of heart rate (HR). A protocol was designed to investigate an impact of five skin types in compliance with Von Luschan's chromatic scale. Thirty-three healthy male subjects between the ages of 18 and 41 were involved in the protocol implemented by means of the OEPS system. The results show that there is no significant difference (p: 0.09, F = 3.0) in five group tests with the skin types across various activities throughout a series of consistent measurements. The outcome of the present study demonstrates that the OEPS, with its multi-wavelength illumination characteristics, could open a path in multiple applications of different ethnic groups with cost-effective health monitoring. [ABSTRACT FROM AUTHOR]

Existing denoising algorithms based on a simplified signal-dependent noise model are valid under the assumption of the predefined parameters. Consequently, these methods fail if the predefined conditions are not satisfied. An adaptive method for eliminating random noise from the simplified signal-dependent noise model is presented in this paper. A linear mapping function between multiplicative noise and noiseless image data is established using the Maclaurin formula. Through demonstrations of the cross-correlation between random variables and independent random variable functions, the mapping function between the variances of multiplicative noise and noiseless image data is acquired. Accordingly, the adaptive denoising model of simplified signal-dependent noise in the wavelet domain is built. The experimental results confirm that the proposed method outperforms conventional ones. [ABSTRACT FROM AUTHOR]

Incorporation of nanomaterials with controlled molecular architecture shows great promise in improving electronic communication between biomolecules and the electrode substrate. In electrochemical applications metal nanoparticles (NPs) modified electrodes have been widely used and are emerging as candidates to develop highly sensitive electrochemical sensors. There has been a growing technological interest in modified indium tin oxide (ITO) electrodes due to their prominent optoelectronic properties and their wide use as a transducing platform. The introduction of NPs into the transducing platform is commonly achieved by their adsorption onto conventional electrode surfaces in various forms, including that of a composite. The aim of this review is to discuss the role of metallic NPs for surface fabrication of ITO thin films leading to detection of specific biomolecules and applications as a biosensor platform. [ABSTRACT FROM AUTHOR]

An optical biosensor for label-free detection of ochratoxin A (OTA) in beer samples is presented. The biosensor consists of an array of ten Mach-Zehnder interferometers (MZIs) monolithically integrated along with their respective broad-band silicon light sources on the same Si chip (37 mm 2 ). The chip was transformed to biosensor by functionalizing the MZIs sensing arms with an OTA-ovalbumin conjugate. OTA determination was performed by pumping over the chip mixtures of calibrators or samples with anti-OTA antibody following a competitive immunoassay format. An external miniaturized spectrometer was employed to continuously record the transmission spectra of each interferometer. Spectral shifts obtained due to immunoreaction were transformed to phase shifts through Discrete Fourier Transform. The assay had a detection limit of 2.0 ng/ml and a dynamic range 4.0–100 ng/ml in beer samples, recoveries ranging from 90.6 to 116%, and intra- and inter-assay coefficients of variation of 9% and 14%, respectively. The results obtained with the sensor using OTA-spiked beer samples spiked were in good agreement with those obtained by an ELISA developed using the same antibody. The good analytical performance of the biosensor and the small size of the proposed chip provide for the development of a portable instrument for point-of-need determinations. [ABSTRACT FROM AUTHOR]

The organic/silicon (Si) hybrid heterojunction solar cells (HHSCs) have attracted considerable attention due to their potential advantages in high efficiency and low cost. However, as a newly arisen photovoltaic device, its current efficiency is still much worse than commercially available Si solar cells. Therefore, a comprehensive and systematical optoelectronic evaluation and loss analysis on this HHSC is therefore highly necessary to fully explore its efficiency potential. Here, a thoroughly optoelectronic simulation is provided on a typical planar polymer poly (3,4-ethylenedioxy thiophene):polystyrenesulfonate (PEDOT:PSS)/Si HHSC. The calculated spectra of reflection and external quantum efficiency (EQE) match well with the experimental results in a full-wavelength range. The losses in current density, which are contributed by both optical losses (i.e., reflection, electrode shield, and parasitic absorption) and electrical recombination (i.e., the bulk and surface recombination), are predicted via carefully addressing the electromagnetic and carrier-transport processes. In addition, the effects of Si doping concentrations and rear surface recombination velocities on the device performance are fully investigated. The results drawn in this study are beneficial to the guidance of designing high-performance PEDOT:PSS/Si HHSCs. [ABSTRACT FROM AUTHOR]

This article reports a portable optoelectronic instrumentation system for real-time monitoring ofEscherichia colicultivation. The minimally invasive sensor offers continuous measurement of the pH, dissolved oxygen, optical density, and auto-fluorescence. The analytical figures of merit, including the stability, response time, reproducibility, and long-term sensitivity, were evaluated before application for monitoring bacterial cell cultivation. The results were compared with values obtained with commercially-available instrumentation and were similar and comparable. The absolute error was between ±0.30 pH units and mg/L for dissolved oxygen. This minimally invasive, simple, and inexpensive optical system is suitable for monitoring online bacterial cell growth in a single transparent container. [ABSTRACT FROM PUBLISHER]

SPECIFIC POLYMERS is a SME acting as R&D service provider in the field of functional monomers, polymers and materials with high specificity. In more than 12 years, SP has developed the synthesis of more than 1000 functional building blocks, monomers and polymers and is now working with more than 400 customers and partners in more than 30 countries worldwide in all field of applications such as surface finishing (glass, metal, metal oxides, nanoparticles, plastics), aeronautic, automotive, pharmaceutical industry, cosmetic, electronic, optic, energy (fuel cells, solar cells or lithium batteries). Since 2013, SP is developing innovative materials for electronic devices. As for example, SP is involved in PiezoMAT European Project and develops UV-crosslinkable thin layer polymeric materials for the encapsulation of ZnO nanowires (NWs) in multi-NWs pressure based fingerprint sensors. [ABSTRACT FROM AUTHOR]

This work presents a monolithically integrated synchronous optical receiver fabricated in a standard 0.35μm CMOS process. The receiver consists of a regenerative latch acting as a sense amplifier; two highly effective, low-capacitance pin photodiodes connected to its output nodes (one of them blocked to the light); and an adjustable reference current to compensate the dynamic offset created by the asymmetries between the parasitic capacitances of the photodiodes. For λ = 635nm, a sensitivity of −25.8 dBm, −26.0 dBm, and −28.4dBm is obtained, respectively, for 400 Mbit/s, 350 Mbit/s, and 250 Mbit/s (BER = 10 −9 ). The power consumption is 670μW, which translates to an energy efficiency of 1.7 pJ/bit at 400 Mbit/s. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a simple and rapid method based on colorimetric sensor array (CSA) for evaluation of warmed-over flavour (WOF) in cooked chicken. All samples were classified according to storage time by CSA coupled with principle component analysis (PCA) or hierarchical cluster analysis (HCA). The CSA data were used to establish prediction models with thiobarbituric acid reactive substances (TBARS), pentanal, hexanal, or heptanal associated with WOF by partial least square regression (PLSR). For the TBARS model, the coefficient of determination ( r p 2 ) was 0.9997 in the prediction range of 0.28–0.69 mg/kg. In each of the models for pentanal, hexanal, and heptanal, all r p 2 were higher than 0.960 in the range of 0.58–2.10 mg/kg, 5.50–11.69 mg/kg, and 0.09–0.16 mg/kg, respectively. These results demonstrate that the CSA was able to predict WOF development and to distinguish between each storage time. [ABSTRACT FROM AUTHOR]

This paper presents a multi-axis force/torque sensor based on simply-supported beam and optoelectronic technology. The sensor's main advantages are: (1) Low power consumption; (2) low-level noise in comparison with conventional methods of force sensing (e.g., using strain gauges); (3) the ability to be embedded into different mechanical structures; (4) miniaturisation; (5) simple manufacture and customisation to fit a wide-range of robot systems; and (6) low-cost fabrication and assembly of sensor structure. For these reasons, the proposed multi-axis force/torque sensor can be used in a wide range of application areas including medical robotics, manufacturing, and areas involving human-robot interaction. This paper shows the application of our concept of a force/torque sensor to flexible continuum manipulators: A cylindrical MIS (Minimally Invasive Surgery) robot, and includes its design, fabrication, and evaluation tests. [ABSTRACT FROM AUTHOR]

The paper presents an optical based measurement system to monitor the fermentation process of food samples, such as raw milk, pasteurized milk, curd, grape juice and batter. The microbial growth during the fermentation and its effects in changing the parameters such as pH, dissolved oxygen, optical density and fluorescence are observed continuously by using minimal invasive optical sensing system. The sensing membranes for pH and dissolved oxygen are prepared using sol-gel technique and attached at an inner wall of a single-cell transparent container. The opto-electronic system is constructed to hold a single-cell transparent container along with light sources, detectors, signal processing circuits, computational and display unit. The performance characteristics, such as stability, response time and reproducibility are verified before it has been applied for food fermentation analysis. The developed optical sensor system shows the maximum relative error rate of 3.98% and a minimum of 0.21% for the pH measurement and for the dissolved oxygen measurement the relative error rate is observed between 0.36% and 3.75%. The results are found comparable and the proposed simple and cost effective system may be considered to monitor the food grades at the household level. [ABSTRACT FROM AUTHOR]

A prototype optoelectronic hygrometer, based on absorption of laser light tuned to absorption specific rovibronic absorption line of H2O at 1364.68961 nm is described. Target application is meteorology, in particular precise and fast measurements of small-scale humidity fluctuations in turbulent atmospheric flows. Tests of the prototype instrument performed in the atmospheric boundary layer have proven the advantage of this optoelectronic sensor over typical, commercially available UV hygrometers designed for similar applications [ABSTRACT FROM AUTHOR]

We investigated the structural and optoelectronic properties of p-n germanium nanocrystals based junctions embedded between GaAs substrate and layers of ZnO:Al or a-Si:H. Scanning electron microscopy and scanning tunneling microscopy were used on these junctions in this work. Calculations of tunneling current on the substrate showed effect of localized defects trapping Fermi level at the surface tending to make a semi-insulating substrate. The average value of the diameter of the Ge nanoparticle is around 12.5 nm. These results lay the foundation for the development of solar cells which active part is made of GeNCs. [ABSTRACT FROM AUTHOR]

A general concept for the development of flow analysis system for non-invasive, bloodless monitoring of uremic toxins’ removal in the course of clinical hemodialysis treatment is presented. The monitor operates in both (discrete and continuous) modes of measurements. In this study as a model uremic marker creatinine has been chosen. The monitor is based on solenoid operated microdevices (pumps and valves) and an optoelectronic flow-through detector made of paired light emitting diodes allowing photometric determination of this metabolite using Jaffé method. Additionally, a simple two microsolenoid pump-based module allowing the modeling of toxin removal by artificial kidney has been developed. The developed monitor has been validated with real samples of postdialysate fluid produced by artificial kidney in the course of clinical hemodialysis treatment. The results of hemodialysis monitoring are fully comparable with those obtained using reference off-line method. [ABSTRACT FROM AUTHOR]

Light-intensity modulated (LIM) force sensors are seeing increasing interest in the field of surgical robotics and flexible systems in particular. However, such sensing modalities are notoriously susceptible to ambient effects such as temperature and environmental irradiance which can register as false force readings. We explore machine learning techniques to dynamically compensate for environmental biases that plague multi-axis optoelectronic force sensors. In this work, we fabricate a multisensor: three-axis LIM force sensor with integrated temperature and ambient irradiance sensing manufactured via a monolithic, origami-inspired fabrication process called printed-circuit MEMS. We explore machine learning regression techniques to compensate for temperature and ambient light sensitivity using on-board environmental sensor data. We compare batch-based ridge regression, kernelized regression and support vector techniques to baseline ordinary least-squares estimates to show that on-board environmental monitoring can substantially improve sensor force tracking performance and output stability under variable lighting and large (>100 °C) thermal gradients. By augmenting the least-squares estimate with nonlinear functions describing both environmental disturbances and cross-axis coupling effects, we can reduce the error in F x , F y and F z by 10%, 33%, and 73%, respectively. We assess viability of each algorithm tested in terms of both prediction accuracy and computational overhead, and analyze kernel-based regression for prediction in the context of online force feedback and haptics applications in surgical robotics. Finally, we suggest future work for fast approximation and prediction using stochastic, sparse kernel techniques. [ABSTRACT FROM AUTHOR]

V-shaped Tröger′s base core has been investigated as a central linking unit in the synthesis of new charge-transporting materials for optoelectronic applications. The studied molecules have been synthesized in two steps from relatively inexpensive starting materials, and demonstrate high glass transition temperatures, good stability of the amorphous state, and comparatively high hole drift mobility (up to 0.011 cm2 V−1 s−1). [ABSTRACT FROM AUTHOR]

A compact flow analysis system for non-invasive, dialysate-side monitoring of phosphate removal in the course of clinical hemodialysis treatment is presented. The monitor is based on solenoid operated micro-pumps and extremely cheap optoelectronic flow-through detector allowing photometric determination of phosphate in spent dialysate using a molybdenum blue method. The monitor can operate in both, discrete and continuous modes of measurement. The analytical utility of monitor has been tested with samples of spent dialysate produced by artificial kidney in the course of real hemodialysis sessions. The results of monitoring are comparable with those obtained using reference off-line method recommended for clinical analysis. Additionally, the possibility of two-side (dialysate and blood) monitoring of hemodialysis treatments with optoelectronic flow-through detectors has been announced. [ABSTRACT FROM AUTHOR]

All-inorganic cesium lead-halide perovskite nanocrystals have emerged as attractive optoelectronic nanomaterials owing to their stabilities and highly efficient photoluminescence. Herein we report a new type of highly luminescent perovskite-related CsPb2Br5 nanoplatelets synthesized by a facile precipitation reaction. The layered crystal structure of CsPb2Br5 promoted an anisotropic two-dimensional (2D) crystal growth during the precipitation process, thus enabling the large-scale synthesis of CsPb2Br5 nanoplatelets. Fast anion exchange has also been demonstrated in as-synthesized CsPb2Br5 nanoplatelets to extend their photoluminescence spectra to the entire visible spectral region. The large-scale synthesis and optical tunability of CsPb2Br5 nanoplatelets will be advantageous in future applications of optoelectronic devices. [ABSTRACT FROM AUTHOR]

Three compact flow analysis systems based on flow-through optoelectronic devices and microsolenoid pumps and valves dedicated for determination of urea in effluent liquid produced by artificial kidney in the course of hemodialysis treatments have been developed. The developed photometric devices operate according to paired detector diode principle. For the first flow analysis system an optoelectronic urea biosensor based on pH-sensitive film enzymatically modified with urease has been applied. In the second system open-tubular urease biosensor and optical detector of ammonia by Berthelot reaction have been used. The third non-enzymatic analytical system is based on optoelectronic detector of the product formed in reaction of urea with modified Ehrlich reagent. The analytical utility of developed flow analysis systems has been tested with real samples of spent dialysate. The results of dialysate urea nitrogen determination are comparable with those obtained using reference off-line method recommended for clinical analysis. Advantages and drawbacks of developed prototypes have been compared and discussed. [ABSTRACT FROM AUTHOR]

A new device for continuous measurement of fruit or stem growth on the basis of an optoelectronic reflex sensor and a microcontroller board was developed and successfully tested under open field conditions. The principle of the system is based on the detection of alternating narrow white and blacks bars printed on a flexible tape, which is tightened as a loop around the measured object and slides under an infrared reflex sensor in response to the object’s radial growth. The design of this new sensor allows continuous, long term measurements without the need of periodic maintenance or physical adjustments of the measurement device. The new system measures changes of fruit or stem perimeter rather than diameter, thus yielding a more relevant information about the growth of objects which are intrinsically not of perfectly circular cross-sectional shape. The described sensor is very lightweight and does not require any mechanical frame or support structure. The tested prototypes had a measurement resolution of 0.5 mm of perimeter, corresponding to a resolution of about 0.16 mm of diameter for a spherical object. The cost of the sensor is very modest, as it consists of only few and inexpensive components. [ABSTRACT FROM AUTHOR]

We have investigated physisorption of CO gas molecules on armchair graphene nanoribbons (5-AGNRs) using first principles methods. The adsorption geometries, adsorption energies, and transferred charge are obtained. To take the van der Waals forces into account, the Grimme correction has been added to the calculation method. The transmission and optical spectrum and current-voltage ( I- V) characteristic of the nanoribbons are calculated as a function of CO concentration for sensing features. We have found that the electronic and transport properties of the AGNR are sensitive to the CO physisorption, and the current through the nanoribbons increases by increasing CO density at the same bias voltage. Our results point out that CO physisorption does not have any effect on the optical properties of the pristine AGNR, however, it can extremely suppress the optical spectra of nitrogen-doped AGNR. The nitrogen-doped AGNR becomes more transparent by adding CO molecules. Also, the HSE06 hybrid functional has been used to improve the optical properties such as the optical gap. The transport and optical features indicate that CO molecules can be detected by GNR-based sensors. [ABSTRACT FROM AUTHOR]

Background: Following diaphragmatic plication for unilateral paralysis, the effect on global chest wall function are unknown. Our hypothesis was that chest wall function would improve in both sides of the chest after plication of the paralysed side.Case Presentation: Using Optoelectronic Plethysmography, total and regional chest wall volumes were measured in one patient before and after left diaphragmatic plication. Volumes were recorded at quiet breathing. Respiratory capacity improved during quiet breathing when measured before and 6 months after surgery. These improvements occur at the abdominal-rib cage level in both operated and contralateral. Prior to surgery the abdominal rib cage motion was out of phase to the upper rib cage and abdominal compartment in both sides of the chest. Synchrony of all three compartments was restored after plication.Conclusion: This physiological study is the first published data in humans to show improvement in chest wall motion both in operated and contralateral side following diaphragmatic plication for unilateral paralysis. [ABSTRACT FROM AUTHOR]

III-V nanowires are candidate building blocks for next generation electronic and optoelectronic platforms. Low bandgap semiconductors such as InAs and InSb are interesting because of their high electron mobility. Fine control of the structure, morphology, and composition are key to the control of their physical properties. In this work, we present how to grow catalyst-free InAs1-xSbx nanowires, which are stacking fault and twin defect-free over several hundreds of nanometers. We evaluate the impact of their crystal phase purity by probing their electrical properties in a transistor-like configuration and by measuring the phonon-plasmon interaction by Raman spectroscopy. We also highlight the importance of high-quality dielectric coating for the reduction of hysteresis in the electrical characteristics of the nanowire transistors. High channel carrier mobilities and reduced hysteresis open the path for high-frequency devices fabricated using InAs1-xSbx nanowires. [ABSTRACT FROM AUTHOR]

Orderly molecular self-assembly for tunable micro/nanostructures is an effective way to prepare novel functional materials with desired properties. Squarylium cyanine (SCy) dyes have received great attention in the fields of laser, imaging, and optoelectronic device. However, the detailed self-assembly behavior of SCy has rarely been investigated. In the present work, two SCy derivatives, D1 and D2, respectively, bearing four and two carboxylic acid groups at different positions are prepared and used as a model system to investigate the molecular self-assembly, morphology, and optical properties of SCy dyes. The hydrogen-bonding interactions between the carboxylic acid groups in D1 and D2 are determined with X-ray diffraction, 2D nuclear magnetic resonance, and Fourier transformation infrared spectroscopy. The two types of hydrogen bonds in D1 cooperating with inherent π-π stacking interaction result in tunable molecular aggregations, which further leads to the transformation between J-aggregation and H-aggregation of D1 in the solid state in response to ammonia gas. In all, this work provides a feasible and effective way to study the self-assembled aggregates of SCy dyes at both molecular and supramolecular levels, and has developed a reversible sensor for ammonia gas detection. [ABSTRACT FROM AUTHOR]

We report a detailed investigation of the stability of a CO2 laser with feedback as described by a six-dimensional rate-equations model which provides satisfactory agreement between numerical and experimental results. We focus on experimentally accessible parameters, like bias voltage, feedback gain, and the bandwidth of the feedback loop. The impact of decay rates and parameters controlling cavity losses are also investigated as well as control planes which imply changes of the laser physical medium. For several parameter combinations, we report stability diagrams detailing how laser spiking and bursting is organized over extended intervals. Laser pulsations are shown to emerge organized in several hitherto unseen regular and irregular phases and to exhibit a much richer and complex range of behaviors than described thus far. A significant observation is that qualitatively similar organization of laser spiking and bursting can be obtained by tuning rather distinct control parameters, suggesting the existence of unexpected symmetries in the laser control space. [ABSTRACT FROM AUTHOR]

In this contribution, a multicommutated flow analysis (MCFA) system for immunoprecipitation assays is presented. The developed bioanalytical system constructed from microsolenoid devices coupled with an optoelectronic flow-through nephelometric detector is sufficient to monitor the kinetics of antigen–antibody interactions, the effect of which is turbidity. Because of the uncommon shape of the immunoprecipitation response curve, the developed MCFA system contains a special module for on-line dilution of the analyzed samples and for single-standard calibration. As a model analyte and an immunoreceptor for the presented investigations, human albumin and antibody for this albumin were used, respectively. The proposed MCFA system is characterized by robust construction, low reagent consumption (maximum 42 μL of undiluted reagent for the analysis of one sample) and relatively high throughput under optimal conditions (approximately 18 measurements per hour). The analytical usefulness of the developed MCFA system for clinical analysis has been experimentally confirmed. Samples of human urine were analyzed for the needs of microalbuminuria diagnostics and satisfactory analytical results have been obtained. [ABSTRACT FROM AUTHOR]

This study presents the use of a multi-channel opto-electronic sensor (OEPS) to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare. The aim of this work was to study how to capture the heart rate (HR) efficiently through a well-constructed OEPS and a 3-axis accelerometer with wireless communication. A protocol was designed to incorporate sitting, standing, walking, running and cycling. The datasets collected from these activities were processed to elaborate sport physiological effects. t-test, Bland-Altman Agreement (BAA), and correlation to evaluate the performance of the OEPS were used against Polar and Mio-Alpha HR monitors. No differences in the HR were found between OEPS, and either Polar or Mio-Alpha (both p > 0.05); a strong correlation was found between Polar and OEPS (r: 0.96, p < 0.001); the bias of BAA 0.85 bpm, the standard deviation (SD) 9.20 bpm, and the limits of agreement (LOA) from -17.18 bpm to +18.88 bpm. For the Mio-Alpha and OEPS, a strong correlation was found (r: 0.96, p < 0.001); the bias of BAA 1.63 bpm, SD 8.62 bpm, LOA from -15.27 bpm to +18.58 bpm. These results demonstrate the OEPS to be capable of carrying out real time and remote monitoring of heart rate. [ABSTRACT FROM AUTHOR]

Synchronous movement of attached self-lifting scaffolds (ASLS) is very important to ensure the safe and economic construction of high-rise buildings. Existing controlling methods for ensuring synchronous movement of ASLS are focused on the measurement of the relative displacement of ASLS modules with simple sensors. It is difficult to acquire the accurate relative module positions. In this article, an improved method is presented for controlling the ASLS synchronous movement based on an optoelectronic sensor array. Firstly, connected pipes were mounted on ASLS modules and the relative liquid level can be detected by the sensor array mounted on the pipe. When the ASLS is lifted or lowered, the relative movement of different ASLS modules leads to the change of the liquid levels, which are then instantly detected and recorded by the sensor array. The relative moving displacements of each ASLS module are obtained which were then compared to the allowable value designated by the construction specifications. Experimental result shows that the proposed model has effectively improved the controlling accuracy with an average agreement of 92.7% and 96.5% with the required allowable relative movement of 30 mm and 80 mm respectively, which leads to the decreased switching on or off of AC (alternating current) contactors and prolongs the service life of AC contactors. Additionally, the movement difference is accurately measured with a resolution of 2.0 mm. The synchronous movement of all ASLS modules is ensured. Finally, statistical data regarding the failure of the AC contactors are collected and it shows that the failure ratio of AC contactor is effectively reduced from 1.18% to 0.69%, indicating a sustainable solution for the synchronous movement control of ASLS. [ABSTRACT FROM AUTHOR]