Simple Device Research Articles

Performing hardness classification using diffusive memristor based artificial neurons

Abstract Artificial neurons and synapses are the building blocks for constructing a neuromorphic system such as Spiking Neural Network (SNN) or Artificial Neural Network (ANN). Recently, there has been tremendous interest in using memristors to develop neuromorphic technologies that can be used in advanced SNNs and ANNs. Memristors, because of their simple device structure, easy and high-density fabrication, and integration with other semiconductor electronics are suitable candidates for the construction of neuromorphic concepts. However, not much has been discussed about using memristors for the development of sensors that can be utilized for object- classification especially their rigidity, shape and structure. In this article, we propose the application of memristors, specifically silver nanoparticle based diffusive memristor, in conjunction with a piezoelectric sensor within a robotics gripper, serving as one receptor (a tactile sensor) that triggers neuron circuitry with memristors to generate spikes. Furthermore, to perform hardness classification, we utilized various objects to collect data and generated multiple spikes corresponding to each object. This data was then utilized with a machine learning algorithm. The outcomes were compared with the accuracy of commercial FSR tactile sensors. Our approach demonstrated the capability of diffusive memristors in generating neuron spikes from tactile stimuli for hardness classification, achieving accuracy ranging from 82% to 100% during the validation of 20% test data across various algorithms, while the FSR sensors achieved an accuracy range of 95% to 98%.

Wearable Patch Biosensor through Electrothermal Film-Stimulated Sweat Secretion for Continuous Sweat Glucose Analysis at Rest.

Wearable patch biosensors for noninvasive and continuous diabetes management through sweat glucose analysis present a promising prospect. However, how to obtain sweat samples safely and effectively remains a huge challenge, especially in a resting state. In this work, we propose an innovative wearable patch biosensor through a heat-stimulated approach for sweat collection. A silver nanowire-loaded electrothermal film was designed as the heat source to stimulate sweat glands for sweat secretion. Subsequently, the secreted sweat sample was transported and enriched through microfluidic channels, which was continuously and sensitively analyzed by a Prussian blue and glucose oxidase comodified glucose electrochemical biosensor. Under optimal conditions, its sensitivity could achieve 14 μM sweat glucose within 15 min, which was 17 min shorter than that without heating. The specificity, reproducibility, and accuracy were also adequate. To achieve on-body perspiration monitoring of human subjects, the wearable patch biosensor was integrated with a portable electrochemical workstation, a temperature controller, and a power source. The glucose concentration was presented on a smartphone. Results showed that the glucose concentration in sweat detected by the wearable biosensor presented a highly consistent trend with the blood glucose measured by a blood glucose meter throughout the day with normal meals. Compared with other conventional sweat stimulation strategies, the simple device and safe principle made it more suitable for individuals who were sedentary or at rest. This work provides a new approach to realizing wearable patch biosensors for personalized health monitoring.

Microfluidic Synthesis of Magnetic Nanoparticles for Biomedical Applications.

Magnetic nanoparticles have attracted great attention and become promising candidates in the biomedicine field due to their special physicochemical properties. They are generally divided into metallic and non-metallic magnetic nanoparticles, according to their compositions. Both of the two types have shown practical values in biomedicine applications, such as drug delivery, biosensing, bioimaging, and so on. Research efforts are devoted to the improvement of synthesis strategies to achieve magnetic nanoparticles with controllable morphology, diverse composition, active surface, or multiple functions. Taking high repeatability, programmable operation, precise fluid control, and simple device into account, the microfluidics system can expand the production scale and develop magnetic nanoparticles with desired features. This review will first describe different classifications of promising magnetic nanoparticles, followed by the advancements in microfluidic synthesis and the latest biomedical applications of these magnetic nanoparticles. In addition, the challenges and prospects of magnetic nanoparticles in the biomedical field are also discussed.

Determinants of Mobile Phone Usage Among Young Adults in Zanzibar

Mobile phones have become a ubiquitous communication tool, particularly among young adults. What was once a simple technological device has now transformed into a social tool, deeply embedded in the daily lives of these individuals. This paper explores mobile phone usage among young adults in Zanzibar from behavioral, economic, and psychological perspectives. Data was collected from 375 participants, consisting of Zanzibar youth aged 16 to 40, residing in both rural and urban areas, through semi-structured interviews. The findings indicate that young adults utilize mobile phones for various purposes, including communication with family and friends, browsing the internet, consuming media, and playing games. The study also delved into the extent of mobile phone dependency, as well as the positive and negative attitudes surrounding its use. It was found that many young adults spend excessive time and money on mobile phones, sometimes prioritizing airtime and data bundles over basic necessities. The paper concludes with recommendations aimed at fostering balanced mobile phone usage among the younger generation

A novel micromixer based on coastal fractal for manufacturing controllable size liposome

The traditional lipid preparation methods are complex, time-consuming, and consume a large amount of reagents, increasing costs and difficulties. Although microfluidic technology is considered a promising solution, achieving controllable liposome production with a simple and inexpensive microfluidic mixing device remains an important problem. This paper presents a wall-type micro-mixer based on coastal zone fractals. Four parameters related to the geometric shape of the coastline fractal in the microchannel are used as design variables, and the mixing index is the objective function. Single-objective optimization numerical analysis of the primary wall-type fractal baffle micromixer under four Reynolds numbers conditions yields the optimal structural configuration. Visualization experiments verify the correctness and accuracy of the numerical simulation, and the optimized mixer is used to produce liposomes. The results show that the micro-mixer with the optimal double-sidewall cross arrangement enhances chaotic convection and improves mixing efficiency. At Re = 0.1 and Re = 100, the mixing efficiency reaches 99%, 50.44% higher than the reference design. By changing the relative flow rates of lipid and aqueous solutions, microfluidic blank liposomes with a particle size of 165.12 ± 11.6 nm and a polydispersity index of 0.35± are obtained. This wall-type fractal micro-mixer has broad application prospects due to its high mixing efficiency.

Design of an innovative aptasensor for the detection of chemotherapeutic drug Fludarabine phosphate

Monitoring the concentration of Fludarabine phosphate, a standard chemotherapeutic drug widely used in cancer treatment, is vital for ensuring the drug’s safety and effectiveness, tailoring treatments to individual needs, and consequently improving overall patient outcomes. Regarding the limitations of conventional techniques in terms of complexity, large time measurements, and a high cost, there is an urgent need to develop simple, rapid, and cost-effective devices. In this paper, we report the design of an aptasensor for the specific and selective detection of Fludarabine. Systematic evolution of ligands by exponential enrichment (SELEX) protocol was performed to select a specific aptamer for Fludarabine. Eleven rounds were carried out, and nine sequences were selected. Based on the dissociation constant (Kd), Ful-3, exhibiting the highest affinity (18.86 nM), was chosen and integrated into a simple electrochemical aptasensing platform for Fludarabine detection. Electrochemical results demonstrated good performance of the selected aptamer in detecting Fludarabine within the analytical range of 1 to 150 pg/mL and with LOD and LOQ in the order of 0.11 pg/mL (0.31 fM) and 0.39 pg/mL (1.06 fM), respectively. The developed platform also showed good selectivity against different analogous molecules and high applicability in serum-spiked samples, with recovery percentages ranging from 96.81 to 99.04%. Considering the encouraging results, this research presents an excellent alternative in terms of simplicity, stability, ease of use, reduction of sample volume, and low cost.

A Critical Review on Various Buffer Layers used to Enhance the Photovoltaic Performance of Organic Solar Cells

Abstract: Due to the high need for sustainable energy sources, there has been a tremendous increase in SC (solar cell) production and research in recent years. Despite the fact that inorganic SC has led the SC consumer market due to its exceptional efficiency, its expensive and difficult manufacture method makes it unaffordable. Hence alternative technology for SC has been explored by researchers to overcome the draw backs of inorganic SC fabrication. OSC (organic solar cell) alternatively known as polymer SC has the advantage of having lightweight, low production cost, and simple device structure. During the last few years, significant attention has been given in order to overcome the material and technological barriers in OSC devices to make them commercially viable. Buffer layers play a significant part in improving the power conversion efficiencies in OSCs, thus it is necessary to comprehend the underlying microscopic mechanisms that underlie the advancements in order to support the current qualitative knowledge. In this review article, we have studied extensively the impact of different BLs (buffer-layer) in enhancing the PCE (power conversion efficiency) and absorption capabilities of OSCs.

Discovery of EDA‐Complex Photochemical Reactions Using Computational Vision

Herein, we report a multidimensional screening strategy to discover Electron Donor‐Acceptor (EDA) complex photochemical reactions using only simple photographic devices, such as webcams or cellphones, combined with TLC analysis. An algorithm was designed to automatically identify EDA‐complex reactive mixtures in solution by processing digital images from a 96‐well microplate, alongside TLC results. The code detects the absorption region of the mixture in the visible spectrum and quantifies color changes through grayscale values. Integrated automatic TLC analysis further classifies mixtures as colorimetric reactions, non‐reactive, or potentially reactive EDA complexes. Leveraging this screening platform, we have developed a new EDA‐mediated approach to synthesize iminophosphoranes in yields up to 90%.

Simple and disposable device based on gold nanoparticles modified screen-printed carbon electrode for detection of ciprofloxacin

Simple and disposable device based on gold nanoparticles modified screen-printed carbon electrode for detection of ciprofloxacin

Application of Photo-Induced Chirality in Covert Authentication

A new technology to write and read covert information in authentication labels is described. This technology uses the phenomenon of photo-induced chirality in Ge2Sb2Te5 thin films to encode the left- or right-circular or linear polarization of the laser beam used to write the label. The written polarization can be revealed by a simple reading device, which is demonstrated to provide the same qualitative information as reading based on cyclotron circular dichroism spectroscopy and imaging. The suggested method, while based on existing manufacturing approaches, offers a balance between technological complexity for writing and simplicity for reading, and may be advantageous as a new authentication technology.

Carrier Generation and Recombination in AC-QLEDs with a Synergistic Capacitance Effect of ZnO/PVDF Heterofunction Layers.

The alternating current-driven electroluminescence (AC-EL) of Cd-based quantum dots is garnering increasing attention due to advantages such as high efficiency and an extended operating lifetime. However, the generation and transport mechanisms of charge carriers within devices still need to be more understood. Here, we construct a simple device and investigate its luminance mechanisms within a single cycle using time-resolved spectroscopy. We tested the luminance-voltage and luminance-frequency characteristics of the device as the thickness of the insulating layer varied, finding that they both exhibited a trend of initially increasing and then decreasing as the voltage or frequency increased. We subsequently investigated the transient electroluminescent characteristics of the device, which featured a P(VDF-TrFE-CFE) layer as the insulator. This layer prevents carrier injection from the Al electrode, while the ZnO layer acts as a charge-generating layer to provide additional carriers. We observed that with an increase in AC voltage, the strongest luminance peak is advanced in the cycle compared to when lower voltages were applied. The position of the strongest luminance peak is delayed with an increasing AC frequency. The C-V characteristics demonstrated that the synergistic P(VDF-TrFE-CFE)/ZnO exhibited a displacement current transforming to a conduct current, which activates the forward operation of the QLED and enables it to emit light. The mechanism we present may serve as a benchmark for improving the luminance and longevity of such devices.

Use of a Microelectromechanical Systems Sensor for Objective Measurements of Abnormal Head Posture in Congenital Superior Oblique Palsy Patients.

The purpose of this study was to design an objective method for measurement of head positions as achieved with use of a microelectromechanical systems (MEMS) sensor. In addition, to use this system to observe the abnormal head position (AHP) in patients with congenital superior oblique palsy (SOP) before and after their surgery. An MEMS sensor was designed for recording of the pitch, roll, and yaw values of the head position in real time. The MEMS sensor was then fixed on the synoptophore from -30 degrees to +30 degrees positions horizontally and vertically to test the accuracy of these measurements. Then, we tested 13 participants with AHP using the MEMS method and the photographic method and compared their correlations. Finally, the pitch, roll, and yaw values of head positions were measured using this MEMS sensor in 31 patients with congenital SOP as performed before and after their surgery. The MEMS sensor (LPMS-B2; Alubi, Guangzhou, China; 400 hertz [Hz]), as based on the theory of a gyroscope, was designed and connected to a smartphone via Bluetooth. It was able to conveniently record the patient's pitch, roll, and yaw head positions in real time, recordings which were consistent with the scales of the synoptophore (P > 0.05) and good correlations with the photographic method (P < 0.001). The main preoperative AHP in patients with SOP was roll (22/31, 71%). Pre- and postoperative vertical deviations were 16.4 ± 7.3 prism diopters (PD) and 4.1 ± 4.2 PD, respectively (P = 0.001). The AHP in patients with SOP was positively correlated with the angle of extorsion in the dominant eye (P = 0.01), rather than that of the vertical deviation. The MEMS sensor described in this report is a simple, practical, and accurate objective device for use in head position measurements. In patients with SOP, the AHP is related to the angle of extorsion in the dominant eye. The MEMS sensor was designed as a micro-wireless dynamic high-precision device for AHP measurement, which has the potential for use in a clinic.

Unveiling islet heterogeneity using an automated microfluidic imaging system

Islets of Langerhans are a therapeutic target for diabetes and prediabetes. Measurements of therapeutic inhibitory or excitatory concentrations are often performed using large groups of islets, however, the population heterogeneity cannot be observed when examining the ensemble response. Normal islet function and islet response to therapeutic treatment can be affected by islet heterogeneity, influencing the progression of diabetes mellitus. To identify heterogeneity in an islet population, we developed a simple microfluidic device capable of delivering a stimulant to four independent chambers, allowing measurements of individual responses from a population of 20–25 islets. The device enabled accurate delivery of the same stimulant concentration to all four chambers, with an error <1% between chambers. To demonstrate the capability of this system, ensemble and individual EC/IC\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{50}$$\\end{document} measurements of glucose and diazoxide were performed on murine islets. Results showed little heterogeneity of glucose EC\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{50}$$\\end{document} values with all 21 islets within ± 0.6 mM of the ensemble value of 7.4 mM. In contrast, application of diazoxide to 24 islets in the presence of 20 mM glucose resulted in 37% of islets having an IC\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{50}$$\\end{document} greater than 10% from the ensemble value of 10.2 μM. The simple system developed here is amenable to further studies on islet heterogeneity, and is applicable to investigate heterogeneity in other cell types.

Wrinkled Rhenium Disulfide for Anisotropic Nonvolatile Memory and Multiple Artificial Neuromorphic Synapses.

Two-dimensional materials are emerging as potential solutions for high-density nonvolatile memory and efficient neuromorphic computing. However, integrating multidimensional memory and an ideal linear weight updating synapse in a simple device configuration to achieve versatile biomimetic neuromorphic systems remains challenging. Here, we introduce a wrinkled rhenium disulfide (ReS2) transistor, where the wrinkled structure facilitates the carrier trapping/detrapping at the dielectric interface, thus enabling the fusion of nonvolatile memory and both electronic and optoelectronic synaptic functionalities. As a nonvolatile memory, anisotropic wrinkled ReS2 can yield three distinct sets of data across three crystal orientations under identical programming operations. Each set demonstrates exceptional retention and endurance properties. As a neuromorphic synapse, it realizes the linear and symmetric updates of conductance states up to 9 bits and 8 bits, the ultra-low-energy consumption of 75 fJ and 2.5 pJ under the electrical and optical stimuli, respectively. The artificial neural network (ANN) based on electronic synapses gives a superior recognition accuracy of 92.9% for the original handwritten digits. The anisotropic synaptic responses and multiwavelength sensitivities of optoelectronic synapses enable them to execute advanced memory and recognition functions for complex images that encompass a variety of pattern features or color information. This underscores its substantial potential for integration into efficient biomimetic visual systems.

Determination of Nitrobenzenes in Air by a Needle Trap Device (NTD) and Gas Chromatography-Mass Spectrometry (GC-MS)

A simple needle-trap device (NTD) coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine trace levels of nitrobenzenes (NBs) in workplace air. The NTD with sorbent inside the needle was employed for the quantification of nitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, o-nitrochlorobenzene, m-nitrochlorobenzene, and p-nitrochlorobenzene. The optimum temperature and time for desorption of analytes were 270 °C and 4 min, and parameters such as sampling flow rate, breakthrough volume, and storage capability were also optimized. The limits of detection and quantification were in the ranges of 1.8 × 10−4–1.1 × 10−3 and 5.9 × 10−4–3.6 × 10−3 mg m−3, respectively. The developed protocol was successfully applied for the determination of NBs in vehicle repair plants where the highest detected concentration was 0.11 mg m−3. The established NTD-GC-MS generally applies to monitoring trace levels of NBs in the air.

In-situ cured gel polymer/ecoflex hierarchical structure-based stretchable and robust TENG for intelligent touch perception and biometric recognition

Gel-based sensors for next generation touch panels have been acknowledged for their exceptional sensitivity and flexibility. However, these sensors typically depend on a metal grid connection, which is susceptible to structural deformation under heavy stress applications and necessitates external power. Here, we report a novel in-situ cured gel polymer electrode-based triboelectric nanogenerator (GPE-TENG) that is stretchable, semi-transparent, and durable, designed to enable a self-powered touch panel for intelligent touch perception. The in-situ curing of the hierarchical structure of the ionic polymer gel encapsulated within the ecoflex ensures robust adhesion of the ionic conductive polymer gel (PEO/LiTFSI) to the ecoflex layers, addressing the issue of delamination in TENG components under mechanical stress. As a result, the GPE-TENG demonstrates high durability, enduring under stretching of approximately 375 % and sustaining heavy mechanical deformations (under folding, twisting, and rolling) over a long period (approximately 2 months) without loss of functionality. Remarkably, the GPE-TENG exhibits outstanding energy harvesting capabilities with a peak power density of 0.36 W m-2. Notably, the GPE-TENG generates electrical signals through simple device stretching, thus serving as a self-powered wearable sensor for human activity monitoring. Moreover, a 9-digital arrayed (3 × 3) flexible, semi-transparent, and self-powered touch panel based on the GPE-TENG shows multifunctionality, including touch track/pattern recognition (i.e. touch and sliding mode) and a highly accurate (∼98 %) deep learning assisted smart biometric system for user identification.

Streamlining Barkhausen effect measurements: A simplified apparatus approach

The application of the Barkhausen Effect technique is hindered by the complexity and need for standardization in Barkhausen measurement devices. These devices typically comprise several modules for excitation, measurement, conditioning, and signal acquisition/processing, making them more complex than simpler methods such as Eddy Current or Magnetic Flux Leakage. Variations in device parameters among researchers can affect result consistency and interpretation. To address this issue, we propose a streamlined Barkhausen device consisting of a low-complexity measurement-excitation unit directly connected to the power grid. In the proposed device, nearly all signal conditioning and processing are transitioned from hardware, as used in the classic Barkhausen setup, to digital processing. This transition significantly enhances the standardization of the resultant Barkhausen signal. Comparative analysis between this simplified device and a traditional setup revealed no significant differences in signal parameters. The proposed device could function as a portable solution for preliminary tests to determine the feasibility of using the Barkhausen measurement technique. Adopting this simplified device could enhance the utility of the Barkhausen technique across various applications.

Metamaterial-inspired infrared electrochromic devices with wideband microwave absorption for multispectral camouflage

Infrared (IR) electrochromic devices, capable of dynamically controlling thermal radiation, hold promising applications in adaptive camouflage. However, the strong microwave reflective properties inherent in the device’s electrodes present a significant challenge, rendering them susceptible to radar detection and weakening their camouflage effect. Inspired by the remarkable electromagnetic control capabilities of metamaterials, the integration of frequency selective surfaces into IR electrochromic devices is proposed to address this multispectral compatibility challenge. The designed integrated metadevices simultaneously exhibit large and reversible IR emissivity tunability (Δε≥0.55 at 3–5 μm, Δε≥0.5 at 7.5–13 μm) and wideband microwave absorption (reflection loss ≤−10 dB at 8.5–18 GHz). Furthermore, the monolithic integrated design of the shared barium fluoride substrate offers a simple device architecture, while careful design considerations mitigate coupling between IR electrochromism and microwave wideband absorption. This work introduces opportunities for the development of multispectral adaptive camouflage systems, offering potential advancements in concealment technology.

THE TRAINING OF TEMPERATURE MONITORING SYSTEM WITH LM35 SENSOR BASED ON RESBEERY PI

Abstract. This community service activity aims to train the community on developing and implementing a temperature monitoring system using the LM35 sensor integrated with Raspberry Pi. This training was carried out to improve people's understanding and skills, especially in utilizing microcontroller-based technology and IoT (Internet of Things) in daily life, especially in the field of room temperature or environmental monitoring. This activity involves targets, for example, teachers, students, and technicians, at SMA AL-IRSYAD TEGAL, with training methods that include basic theories about temperature sensors, introduction to Raspberry Pi, and hands-on practice in assembling and programming temperature monitoring systems. The results of this training showed that participants could understand the basic concepts of temperature monitoring systems and could apply the knowledge gained in making simple devices that can measure and display temperature in real time. The activity evaluation showed that most of the participants felt helped by this training and showed high interest in further developing the system that had been studied. In the future, it is hoped that similar activities can continue to be carried out to empower the community to utilize technology for daily needs. Keywords: Community service, temperature monitoring system, LM35, Raspberry Pi, technology training.

A custom-built single-channel in-ear electroencephalography sensor for sleep phase detection: an interdependent solution for at-home sleep studies.

Sleep is vital for health. It has regenerative and protective functions. Its disruption reduces the quality of life and increases susceptibility to disease. During sleep, there is a cyclicity of distinct phases that are studied for clinical purposes using polysomnography (PSG), a costly and technically demanding method that compromises the quality of natural sleep. The search for simpler devices for recording biological signals at home addresses some of these issues. We have reworked a single-channel in-ear electroencephalography (EEG) sensor grounded to a commercially available memory foam earplug with conductive tape. A total of 14 healthy volunteers underwent a full night of simultaneous PSG, in-ear EEG and actigraphy recordings. We analysed the performance of the methods in terms of sleep metrics and staging. In another group of 14 patients evaluated for sleep-related pathologies, PSG and in-ear EEG were recorded simultaneously, the latter in two different configurations (with and without a contralateral reference on the scalp). In both groups, the in-ear EEG sensor showed a strong correlation, agreement and reliability with the 'gold standard' of PSG and thus supported accurate sleep classification, which is not feasible with actigraphy. Single-channel in-ear EEG offers compelling prospects for simplifying sleep parameterisation in both healthy individuals and clinical patients and paves the way for reliable assessments in a broader range of clinical situations, namely by integrating Level 3 polysomnography devices. In addition, addressing the recognised overestimation of the apnea-hypopnea index, due to the lack of an EEG signal, and the sparse information on sleep metrics could prove fundamental for optimised clinical decision making.