Low-cost Detector Research Articles

Development and implementation of a low-cost metal detector device

Development and implementation of a low-cost metal detector device

Impact of strain relaxation on the growth rate of heteroepitaxial germanium tin binary alloy

The growth of high-quality germanium tin (Ge1–y Sn y ) binary alloys on a Si substrate using chemical vapor deposition (CVD) techniques holds immense potential for advancing electronics and optoelectronics applications, including the development of efficient and low-cost mid-infrared detectors and light sources. However, achieving precise control over the Sn concentration and strain relaxation of the Ge1–y Sn y epilayer, which directly influence its optical and electrical properties, remain a significant challenge. In this research, the effect of strain relaxation on the growth rate of Ge1–y Sn y epilayers, with Sn concentration >11at.%, is investigated. It is successfully demonstrated that the growth rate slows down by ~55% due to strain relaxation after passing its critical thickness, which suggests a reduction in the incorporation of Ge into Ge1–y Sn y growing layers. Despite the increase in Sn concentration as a result of the decrease in the growth rate, it has been found that the Sn incorporation rate into Ge1–y Sn y growing layers has also decreased due to strain relaxation. Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge1–y Sn y epilayers with tuned Sn concentration and strain relaxation.

Abstract C016: Optical Techniques to Democratize Intravital Quantification of Metabolic Heterogeneity

Abstract Since metabolic and vascular adaptations are essential for tumor cell survival, a technique capable of tracking metabolic heterogeneity at both the bulk tumor and cellular scales over extended timelines is necessary. To address this technological need, we have developed a multi-scale optical microscope relying on exogenous fluorescent reporters for dynamic spatiotemporal imaging of major metabolic pathways in vivo. This microscope utilizes a low-cost CMOS detector and LEDs for excitation to enable fluorescence microscopy in resource-limited settings. Here, we implement our system to assess changes in bulk tumor and cellular metabolic heterogeneity as vasculature is perturbed. 4T1 breast tumor-bearing mice were treated with combretastatin A-1 (a vascular disruptor), implanted with window chambers, and temporally imaged (n=5/group). Fluorescence imaging and Gabor filter/Djikstra segmentation approaches enabled metabolic and vascular analyses, respectively. We demonstrated the system’s ability to acquire co-registered images of vasculature, morphology, and distinct metabolic endpoints reporting on glucose uptake, fatty acid uptake, and mitochondrial metabolism at both wide-field and high resolutions. At 12 hours post-treatment, the tumors’ metabolism shifted from mitochondrial respiration to glycolysis in avascular regions. Further, we report a higher average vascular density in untreated versus treated mice at 108 hours post-treatment (p<0.05, Kolmogorov-Smirnov test). On exploring the relationship between metabolic activity and vasculature, regions with high local tortuosity in the untreated group exhibited a higher reliance on fatty acid uptake than high tortuosity regions in the treatment group, indicating these cells’ reliance on fatty acids within a complex vascular network. Our multiplexed imaging strategy enables the quantification of tumor metabolism and vasculature over multiple length scales, which could be leveraged to study adaptations following clinical therapies. Citation Format: Enakshi Sunassee. Optical Techniques to Democratize Intravital Quantification of Metabolic Heterogeneity [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C016.

Synthetic data at scale: a development model to efficiently leverage machine learning in agriculture.

The rise of artificial intelligence (AI) and in particular modern machine learning (ML) algorithms during the last decade has been met with great interest in the agricultural industry. While undisputedly powerful, their main drawback remains the need for sufficient and diverse training data. The collection of real datasets and their annotation are the main cost drivers of ML developments, and while promising results on synthetically generated training data have been shown, their generation is not without difficulties on their own. In this paper, we present a development model for the iterative, cost-efficient generation of synthetic training data. Its application is demonstrated by developing a low-cost early disease detector for tomato plants (Solanum lycopersicum) using synthetic training data. A neural classifier is trained by exclusively using synthetic images, whose generation process is iteratively refined to obtain optimal performance. In contrast to other approaches that rely on a human assessment of similarity between real and synthetic data, we instead introduce a structured, quantitative approach. Our evaluation shows superior generalization results when compared to using non-task-specific real training data and a higher cost efficiency of development compared to traditional synthetic training data. We believe that our approach will help to reduce the cost of synthetic data generation in future applications.

Nitrogen-Doped Carbon Quantum Dots with Photoactivation Properties for Ultraviolet Ray Detection.

Photoactivation is a phenomenon that could enhance the photoluminescence (PL) and photostability upon UV/vis light exposure, which is usually observed in CdSe/ZnS quantum dots (QDs). However, the photoactivation phenomenon has been scarcely reported in fluorescent carbon quantum dots (CQDs). Herein, the nitrogen-doped carbon quantum dots (N-CQDs) were prepared through a facile solvothermal approach with naphthalenetracarboxylic dianhydride and serine as precursors. Upon simple UV light irradiation for 10 min, the fluorescence quantum yield (QY) of N-CQDs could increase up to 10-fold. Based on this phenomenon, the N-CQDs were explored as an ultraviolet (UV) light sensor to assess the intensity of ultraviolet radiation in sunlight and indirectly evaluate the UV-blocking efficiency of various sunscreen products. Thus, this contribution not only provided an insight into developing a low-cost UV detector but also opened a door for the development of carbon quantum dots with converse-photobleaching properties.

Convenient and Accurate Detection of Dopamine and Glucose by Modifying Carbon Fiber Electrodes

Fast, sensitive, and low-cost high-performance detectors have gradually become an indispensable tool for people to keep healthy, and sensors are the key devices of detection equipment. In this work, a ZnO nanocrystal modified carbon fiber electrode was prepared using a hydrothermal method, and on this basis, a galvanostatic point deposition method was used to load copper nanoparticles to prepare a sensor electrode. Scanning electron microscopy and X-ray diffraction were used to comprehensively analyze composition, morphology, and environmental adaptability of the prepared electrodes. The DPV test was used to verify the enhanced effect of ZnO nanorods on neurotransmitter detection. The ZnO/CF showed an obvious electrical signal (0.22 V, 4 × 10−5A) in the detection of dopamine (DA) solution, and the Cu-NPs/ZnO/CF also showed excellent detection results in the glucose detection experiment., providing two excellent examples for the development of low-cost electrochemical sensors. The electrodes can specifically detect DA in the presence of ascorbic acid and uric acid, and the detection limit of the electrode for detecting DA is about 0.4 μM. In addition, the Cu-NPs/ZnO/CF electrode successfully realized the enzyme-free detection of glucose, and the detection limit could reach 0.5 μM.

A Low-cost Two-in-one Fluorescence/ Colorimetry Ammonium Detector: Design and Application

In this study, a compact and low-cost ammonium detector integrated spectrophotometric and fluorescence detection was designed based on the reaction of ammonium and o-phthalaldehyde in the presence of sodium sulfite solution to form substances with both photometric properties and fluorescence. This two-in-one detector detects ammonium in spectrophotometric mode at high concentrations and in fluorescence mode at low concentrations. The detector with a total size of 5×5×5 cm2 and integrates the detector skeleton box, light source, attenuator, filter, photoelectric sensor, data acquisition card, constant current source circuit, and LabVIEW upper computer acquisition program. Also, the detector was applied to the determination of water samples with a wide range of ammonium concentrations, showing good performance. The detector has the advantages of low cost, miniaturization, easy operation, and wide detection concentration range. This two-in-one detector has good potential for ammonium detection in the field, especially where ammonium concentration varies widely.

Hadamard ghost imaging with a small amount of mask plates based on a spread spectrum.

Ghost imaging techniques using low-cost bucket detectors have unrivaled advantages for some wavebands where plane array detectors are not available or where focusing is difficult. In these bands, fine mask plates are the key to implementing high-resolution and quality ghost imaging. However, manufacturing a large number of mask plates is necessary but undoubtedly expensive in traditional Hadamard ghost imaging (HGI). Inspired by the spread spectrum technology, Hadamard ghost imaging based on spread spectrum (HGI-SS) is proposed, in which only two sets of a small number of mask plates are needed to accomplish Nyquist sampling for the object. Their numbers are equal to the lateral pixel resolution and the vertical pixel resolution of the object, respectively. Optical experiments verify the effectiveness of the scheme. For ghost imaging with a resolution requirement of 128 × 128 pixels, HGI-SS needs to prepare only 256 mask plates, while the traditional HGI needs to prepare 16,384 mask plates. HGI-SS may be helpful to expand the pixel resolution of imaging at a relatively low cost of mask plates.

Long infrared detector based on Se-hyperdoped black silicon

Infrared (IR) detectors play crucial roles in various applications. A significant milestone in advancing the next-generation low-cost silicon technology is the enhancement of hyperdoped black silicon (b-Si) photodetectors, particularly within the IR wavelength range. In this study, highly selenium (Se)-doped b-Si photodetectors. Through the optimization of laser parameters and the application of SiO2 passivation, significant enhancements were achieved in responsivity (R), external quantum efficiency, and specific detectivity (D*) within the long-wave IR range, culminating in a D* of 1.3 × 1012 Jones at 9.5 μm. Additionally, the Se: b-Si photodetectors maintain a D* of approximately 1.3 × 1011 Jones at critical optical telecommunications wavelengths of 1.3 μm and 1.5 μm. These results significantly contribute to the advancement of IR photodetector technology and provide a foundation for the development of highly efficient, low-cost, and broadband IR detectors for Si photonic applications.

A Low-Cost Detector and Eviction Module for Agricultural Bird Pest Design

A Low-Cost Detector and Eviction Module for Agricultural Bird Pest Design

Comparative study of the near-infrared detection of PbSe fabricated using a sputter deposition method

Near-infrared (NIR) light is used in nondestructive spectroscopies to analyze various compounds in several applications. A PbSe nanocrystal film used in NIR detectors is fabricated using a magnetron sputtering process. The PbSe NIR detectors can be fabricated at a low cost and can operate at ambient temperatures. In this study, the surface morphology and chemical and crystal states of PbSe and its NIR detection performance are investigated and compared with existing reports in the literature. The PbSe film grown by sputtering exhibits nano- and columnar crystal structures, predominantly halite-like (100) face-centered cubic structures. The PbSe film contains PbO and SeO2 and exhibits dual-absorption band-to-band transitions at 0.43 and 0.52 eV. The sputtered PbSe film is used to fabricate an NIR photodetector with a metal-semiconductor-metal structure. The detector shows fast rise and decay times of 0.14 and 0.12 s, respectively, and responsivity of approximately 0.01 A/W under infrared illumination. Based on this study, a low-cost PbSe NIR detector that can operate at room temperature is developed for early fire detection.

Quartz as an accurate high-field low-cost THz helicity detector

Emerging concepts employing angular momentum of THz light for ultrafast material control rely on the measurement of undistorted intense THz fields and on the precise knowledge about sophisticated THz helicity states. Here, we establish z-cut α-quartz as a precise electro-optic THz detector for full amplitude, phase, and polarization measurement of highly intense THz fields, all at a fraction of costs of conventional THz detectors. We experimentally determine its detector response function, in excellent agreement with our modeling. Thereupon, we develop a swift and reliable protocol to precisely measure arbitrary THz polarization and helicity states. This two-dimensional electro-optic sampling in α-quartz fosters rapid and cost-efficient THz time-domain ellipsometry and enables the characterization of polarization-tailored fields for driving chiral or other helicity-sensitive quasi-particles and topologies.

Scintillation Properties of CsPbBr3 Nanocrystals Prepared by Ligand-Assisted Reprecipitation and Dual Effect of Polyacrylate Encapsulation toward Scalable Ultrafast Radiation Detectors.

Lead halide perovskite nanocrystals (LHP-NCs) embedded in polymeric hosts are gaining attention as scalable and low-cost scintillation detectors for technologically relevant applications. Despite rapid progress, little is currently known about the scintillation properties and stability of LHP-NCs prepared by the ligand assisted reprecipitation (LARP) method, which allows mass scalability at room temperature unmatched by any other type of nanostructure, and the implications of incorporating LHP-NCs into polyacrylate hosts are still largely debated. Here, we show that LARP-synthesized CsPbBr3 NCs are comparable to particles from hot-injection routes and unravel the dual effect of polyacrylate incorporation, where the partial degradation of LHP-NCs luminescence is counterbalanced by the passivation of electron-poor defects by the host acrylic groups. Experiments on NCs with tailored surface defects show that the balance between such antithetical effects of polymer embedding is determined by the surface defect density of the NCs and provide guidelines for further material optimization.

RAD01: Development of a NUMTEK RAD01 Low-Cost, Portable Digital Gamma Radiation Detector

Additive manufacturing and open-source affordable instruction provide equal opportunities. Therefore, it is possible to quickly, compactly, and cheaply make expensive, scarce, and large devices in the previous century. The Geiger-Muller tube is used for the primary sensing component proposed and incorporates digital signal processing to ensure accurate and reliable measurement of gamma radiation. The performance of the developed detector is evaluated through experimental testing and comparisons with commercially available radiation detection devices. The results demonstrate the detector's ability to provide precise and consistent measurements while remaining cost-effective. Moreover, its portability and user-friendly interface make it suitable for various applications, including environmental monitoring, nuclear safety, personal radiation exposure assessment, and, most importantly, educational purposes. This low-cost portable digital gamma radiation detector contributes to the field of radiation detection by presenting an accessible solution that addresses the financial limitations associated with conventional gamma radiation detectors.

A Low-Cost Arduino-Based LPG Gas Leak Detector and Alarm System for Preventing Fire Accidents in Residential Buildings

A Low-Cost Arduino-Based LPG Gas Leak Detector and Alarm System for Preventing Fire Accidents in Residential Buildings

Investigating the possibility of leakage detection in water distribution networks using cosmic ray neutrons in the thermal region

Water distribution systems can experience high levels of leakage, originating from different sources, such as deterioration due to aging of pipes and fittings, material defects, and corrosion. In addition to causing financial losses and supply problems, leakages in treated water distribution also represent a risk for public health. Despite several techniques for leak detection are already available, there is still a lot of interest in new non-invasive approaches, especially for scenarios where acoustic techniques struggle, such as in noisy environmental conditions.In this work we investigated the possibility of using cosmic ray (CR) neutrons for the detection of underground leakages in water distribution networks, by exploiting the difference in the above ground thermal neutron flux between dry and wet soil conditions. The potential of the technique has been assessed by means of an extensive set of Monte Carlo simulations based on GEANT4, involving realistic scenarios based on the Italian aqueduct design guidelines. Simulation studies focused on sandy soils and results suggest that a significative signal, associated with a leakage, could be detected with a data-taking lasting from a few minutes to a half-hour, depending on the environmental soil moisture, the leaking water distribution in soil, and the soil chemical composition.Finally, a brief description of a new portable and low-cost detector for thermal neutrons, currently under commission, is also presented.

Smartphone as a fluorescence detector for high-performance liquid chromatography

BackgroundFluorescence detection is employed in high-performance liquid chromatography (HPLC) due to its high specificity and sensitivity. However, it is often limited by expensive components and bulkiness. Recently, advances in technology and electronics have led to the development of smartphones that can serve as portable recording, analysis, and monitoring tools. Smartphone-based detection provides advantages of cost effectiveness, rapid signal/data processing, and the display of results on a handhold monitor. The combination of smartphone-based detection with HPLC can offer unique features that are beneficial in overcoming limitations of commercial fluorescence detectors. (90) ResultsA miniaturized and low-cost HPLC fluorescence detector based on a smartphone is introduced for the detection of six fluorescent molecules. The smartphone is able to capture emitted fluorescence in video format while MATLAB code is used for data processing to provide chromatograms based on different detection channels. A custom designed double-channel flow cell was utilized to enable simultaneous detection of fluorescent compounds with different excitation wavelengths. The detector consists of a lab-made flow cell, monochromatic LEDs as the light source, 3D printed housing and connector box, fiber optic cables, and a smartphone. The effects of flow cell geometry, channel width and light slit diameter, as well as a comparison of different flow cell manufacturing techniques, are studied and discussed. The validated system was successfully applied to samples from diverse water sources, yielding spiking recoveries within the range of 91.7% and 109.7%. (141) SignificanceThis study introduces the first smartphone-based fluorescence detector for HPLC with cost-effective and customizable flow cells, allowing for the simultaneous detection of fluorescent compounds with different excitation wavelengths and offering a potential solution for the analysis of co-eluting compounds. Beyond its user-friendly interface and low-cost, smartphone detection in HPLC provides tremendous opportunities in further miniaturizing chromatographic instrumentation while offering high sensitivity and can be expanded to other mechanisms of detection. (70)

One-Dimensional Hybrid Copper(I) Iodide Single Crystal with Renewable Scintillation Properties.

Low-dimensional hybrid copper(I) halides attract considerable attention in the field of light emissions. In this work, we obtained the centimeter-sized single crystal of 1,3-propanediamine copper(I) iodide (PDACuI3) with a solvent evaporation method. The single crystal X-ray diffraction of PDACuI3 reveals that the [CuI4] tetrahedra form the corner-connected chains separated by PDAs, forming a one-dimensional structure with an orthorhombic space group of Pbca. The band gap is determined to be 4.03 eV, and the room temperature photoluminescence (PL) quantum yield is determined to be 26.5%. The thermal quenching and negative thermal quenching of emission are observed via temperature-dependent PL spectra, and our study shows that the intermediate nonradiative state below the self-trapped exciton state may get involved in these temperature-dependent behaviors. The X-ray scintillation performance of PDACuI3 single crystals is also evaluated, and the relative light output renewed to 94.3% of the fresh one after a low-temperature annealing. On the basis of our results, PDACuI3 single crystals provide nontoxicity and renewable scintillation performance, thus showing potential application in the area of low-cost radiation detectors.

Dynamic Breath Limonene Sensing at High Selectivity.

Liver diseases (e.g., cirrhosis, cancer) cause more than two million deaths per year worldwide. This is partly attributed to late diagnosis and insufficient screening techniques. A promising biomarker for noninvasive and inexpensive liver disease screening is breath limonene that can indicate a deficiency of the cytochrome P450 liver enzymes. Here, we introduce a compact and low-cost detector for dynamic and selective breath limonene sensing. It comprises a chemoresistive sensor based on Si/WO3 nanoparticles pre-screened by a packed bed Tenax separation column at room temperature. We demonstrate selective limonene detection down to 20 parts per billion over up to three orders of magnitude higher concentrated acetone, ethanol, hydrogen, methanol, and 2-propanol in gas mixtures, as well as robustness to 10-90% relative humidity. Most importantly, this detector recognizes the individual breath limonene dynamics of four healthy volunteers following the ingestion (swallowing or chewing) of a limonene capsule. Limonene release and subsequent metabolization are monitored from breath measurements in real time and in excellent agreement (R2 = 0.98) with high-resolution proton transfer reaction mass spectrometry. This study demonstrates the potential of the detector as a simple-to-use and noninvasive device for the routine monitoring of limonene levels in exhaled breath to facilitate early diagnosis of liver dysfunction.

Real‐Time Superresolution Interferometric Measurement Enabled by Structured Nonlinear Optics (Laser Photonics Rev. 17(6)/2023)

A Structured-Light Enabled Nonlinear Interferometer In article number 2200967, Zhi-Han Zhu, Xiao-Peng Hu, Bao-Sen Shi, and colleagues describe a structured-light enabled nonlinear interferometer capable of superresolution measurement in real time. Such a novel technique realized the first observation of a 12-photon de Broglie wavelength in real time by using only a low-cost detector, providing a promising new way for the development of superresolution interferometric metrology.