The utilization of fluorescence detection for various biomedical applications such as oximeter sensors, cancer detection, monitoring of protein-DNA interactions, heart stroke detection, etc. has been on the rise which...
详细信息
The utilization of fluorescence detection for various biomedical applications such as oximeter sensors, cancer detection, monitoring of protein-DNA interactions, heart stroke detection, etc. has been on the rise which was first introduced by Heyduk and Lee in 1990. The integration of organic light emitting diode and organic photodiode (OPD) is well suited for these kinds of health-care detections. In this article, a methodology is proposed for Covid-19 detection which consists of a highly flexible blue organic LED (OLED), an OPD, and a human saliva sample. An in-depth investigation is being performed on both the OLED and OPD devices to make these devices suitable for the detection of the SARS-COV-2 virus inside human saliva samples. The presented methodology is based on fluorescence detection. Herein, the OLED emits an excitation wavelength of 470 nm and OPD produces two different currents 63.5 and 37.2 mA corresponding to the emission wavelengths of 490 and 525 nm, correspondingly. It is concluded here that if the OPD produces 63.5 mA current, the person is infected by Covid-19 and if it produces 37.2 mA current, the person is healthy. This article also compares the proposed methodology with some other researcher's work. The proposed OLED-OPD integration may be utilized for other sensing applications such as environmental monitoring, multispectral sensing, optical sensing, IoT devices, etc.
Increasing reliance on digital twin technology for managing indoor environments necessitates the development of spatial expansion virtual sensors (SEVS). However, in practical applications, SEVS performance often dete...
详细信息
Increasing reliance on digital twin technology for managing indoor environments necessitates the development of spatial expansion virtual sensors (SEVS). However, in practical applications, SEVS performance often deteriorates due to shifts in data distribution and environmental conditions, presenting challenges for consistent reliability. Most existing SEVS research has primarily focused on initial model development, with limited consideration to in-situ calibration strategies. This study introduces an autoencoder reconstruction residualWasserstein distance (AR-WD)-based error estimation model, designed for spatial expansion virtual sensors with the primary objective of enhancing their performance in practical applications. The proposed model utilizes residuals from autoencoders and Wasserstein features, which can be derived without additional sensor installations, for real-time calibration. A comprehensive evaluation was conducted using temperature data from a pigsty, where the AR-WD model demonstrated robust performance across various machine learning algorithms, particularly with random forest and XGBoost, showing high predictive accuracy with a mean absolute error as low as 0.086. These findings suggest that the integration of AR-WD features significantly enhances the reliability and accuracy of virtual sensors. In addition, the AR-WD model leverages the unique characteristics of SEVS to enable real-time error estimation based solely on input data variations, thereby addressing common limitations of non-intrusive calibration methods. This research not only advances the field of virtual sensor development but also provides critical insights for optimizing sensor systems in complex indoor settings.
Fiber strain sensors show good application potential in the field of wearable smart fabrics and equipment because of their characteristics of easy deformation and weaving. However, the integration of fiber strain sens...
详细信息
Fiber strain sensors show good application potential in the field of wearable smart fabrics and equipment because of their characteristics of easy deformation and weaving. However, the integration of fiber strain sensors with sensitive response, good stretchability, and effective practical application remains a challenge. Herein, this paper proposes a new strategy based on 3D stress complementation through pre-stretching and swelling processes, and the polydimethylsiloxane (PDMS)/silver nanoparticle (AgNPs)/MXene/carbon nanotubes (CNTs) fiber sensor with the bilayer labyrinthian wrinkles conductive network on the PU fiber surface is fabricated. Benefiting from the wrinkled structure and the synergies of sensitive composite materials, the fiber sensor exhibits good stretchability (>150%), high sensitivity (maximum gauge factor is 57896), ultra-low detection limit (0.1%), fast response/recovery time (177/188 ms) and good long-term durability. It can be used as Morse code issuance and recognition to express the patient's symptoms and feelings. Further, the sensor enables comprehensive human movement monitoring and collects data of different characteristics with the assistance of machine learning, different letters/numbers are recognized and predicted with an accuracy of 99.17% and 99.33%. Therefore, this fiber sensor shows potential as a new generation of flexible strain sensors with applications in medical monitoring and human-computer interaction.
The reliability of rectifiers is regarded as one of the most important factors in traction systems. Unexpected faults occurring in sensors can degrade the performance and lead to secondary faults. Accordingly, a senso...
详细信息
The reliability of rectifiers is regarded as one of the most important factors in traction systems. Unexpected faults occurring in sensors can degrade the performance and lead to secondary faults. Accordingly, a sensor fault diagnosis method is proposed in this paper. It can locate faults and identify fault types. Three high-incidence fault types in current and voltage sensors have been taken into consideration. Only the current residual is needed in the process of fault diagnosis. No additional sensors are required in this method. First, a traction rectifier model is developed. Then, a grid current estimator is constructed, the residual is acquired and applied to fault detection. Next, the residual is analyzed under different kinds of sensor faults. Fault diagnosis functions are constructed and the faults can be diagnosed. Finally, an experiment test is processed to demonstrate the effectiveness of the proposed method.
Rehabilitative gloves with leader-follower control offer a promising approach for stroke patients with impaired hand function. However, the current integration of sensors in rehabilitative soft gloves is limited, whic...
详细信息
Rehabilitative gloves with leader-follower control offer a promising approach for stroke patients with impaired hand function. However, the current integration of sensors in rehabilitative soft gloves is limited, which poses challenges in achieving position feedback and desired bending angles of actuators. Moreover, fine movement perception and recognition add complexity to leader-follower control. Here, we propose a rehabilitative soft glove system with cooperative sensing and fine gesture recognition, utilizing a carbon black (CB) strain sensor and electromyography sensor. The strain sensor has high flexibility and stretchability, and we conducted a comprehensive analysis of its electrical characteristics. It demonstrates an impressive 100% stretchability with a gauge factor of 1.14-1.34. By seamlessly integrating the strain sensors into a data glove, we successfully monitored finger movement and grip. We propose two leader-follower control methods, namely strain sensor-based position control and cooperative sensing-based fine dynamic gesture recognition control. In the former approach, we calibrated of all sensors integrated in the data glove and actuators, enabling position control of the rehabilitative soft glove through an incremental PID controller. For fine dynamic gesture recognition, we introduce a ResNet-ConvLSTM-self-attention (RCSA) deep learning framework that eliminates the need for sensor calibration and achieves an impressive recognition accuracy of 96.20%. Finally, we validate the effectiveness of our proposed control scheme through online experiments with the rehabilitative soft glove.
Purpose - The aging and deterioration of engineering building structures present significant risks to both life and property. Fiber Bragg grating (FBG) sensors, acclaimed for their outstanding reusability, compact for...
详细信息
Purpose - The aging and deterioration of engineering building structures present significant risks to both life and property. Fiber Bragg grating (FBG) sensors, acclaimed for their outstanding reusability, compact form factor, lightweight construction, heightened sensitivity, immunity to electromagnetic interference and exceptional precision, are increasingly being adopted for structural health monitoring in engineering buildings. This research paper aims to evaluate the current challenges faced by FBG sensors in the engineering building industry. It also anticipates future advancements and trends in their development within this field. Design/methodology/approach - This study centers on five pivotal sectors within the field of structural engineering: bridges, tunnels, pipelines, highways and housing construction. The research delves into the challenges encountered and synthesizes the prospective advancements in each of these areas. Findings - The exceptional performance of FBG sensors provides an ideal solution for comprehensive monitoring of potential structural damages, deformations and settlements in engineering buildings. However, FBG sensors are challenged by issues such as limited monitoring accuracy, underdeveloped packaging techniques, intricate and time-intensive embedding processes, low survival rates and an indeterminate lifespan. Originality/value - This introduces an entirely novel perspective. Addressing the current limitations of FBG sensors, this paper envisions their future evolution. FBG sensors are anticipated to advance into sophisticated multi-layer fiber optic sensing networks, each layer encompassing numerous channels. Data integration technologies will consolidate the acquired information, while big data analytics will identify intricate correlations within the datasets. Concurrently, the combination of finite element modeling and neural networks will enable a comprehensive simulation of the adaptability and longevity of FBG sensors in their
With the booming development of smart electronic devices, the forms of wearable sensors are gradually diversifying. However, integrating dual sensing capabilities into a single sensor for decoupled strain and humidity...
详细信息
With the booming development of smart electronic devices, the forms of wearable sensors are gradually diversifying. However, integrating dual sensing capabilities into a single sensor for decoupled strain and humidity detection remains a significant challenge. In this study, we report a flexible dual-modal sensor designed with a "skin-core" structure that integrates pressure and humidity sensing layers, enabling decoupled monitoring of pressure and humidity. Using a coaxial wet-spinning method, we fabricated multifunctional sensing fibers with MXene/CNF as the core and cationic cellulose as the skin. By controlling the ratio of the spinning solution for the core layer, the resulting MXene/CNF@cationic cellulose aerogel fiber (MCC) pressure sensor exhibits high sensitivity (120 kPa-1), rapid response time (50 ms for response, 55 ms for recovery), and excellent cycling stability under compression. Furthermore, the unique structure of the coaxially spun aerogel and the inherent properties of the MCC fiber material endow the sensor with outstanding cycling stability, fast moisture absorption and desorption responses (response time of 9.43 s and recovery time of 5.3 s), and excellent moisture absorption and desorption characteristics. This study promotes the effective utilization of cellulose-based materials in wearable sensing and health management, expands how sensors can be worn, and lays the foundation for the integration of sensors with garments.
Breathing, as a vital physiological parameter, holds significance in reflecting the breathing abnormalities associated with sleep apnea syndrome (SAS) through real-time breathing monitoring. Stretchable strain sensors...
详细信息
Breathing, as a vital physiological parameter, holds significance in reflecting the breathing abnormalities associated with sleep apnea syndrome (SAS) through real-time breathing monitoring. Stretchable strain sensors, designed to match the strain patterns of chest and abdominal movements that accompany breathing, can deform to the maximum extent along with the thoracic and abdominal changes, thereby capturing the intricate details of breathing state variations. In this study, we commence with strain sensors to explore and develop a portable, user-friendly, and cost-effective wearable equipment for real-time breathing monitoring. A core-shell elastic thread composed of a hydrophilic shell and an elastic core is utilized as the substrate, a strain sensor is constructed through a simple immersion method, and carbon-based materials are loaded onto the hydrophilic shell layer. The sensor benefits from the unique weaving structure of the shell, exhibiting a high gauge factor (GF) (25.8) and linearity (0.998) within a strain range of 0%-50%, along with excellent stability (>20 000 cycles). integration of the sensor into a system yields a wireless breathing monitoring device capable of real-time tracking of breathing rate and status. This comprehensive research covers the entire development process, encompassing sensor fabrication, software development, and a specific focus on sleep apnea applications.
The integration of ultra-soft curvature sensors into textile data gloves is essential to enhance user experience with greater flexibility and adaptability, particularly in various human-machine interface scenarios, in...
详细信息
The integration of ultra-soft curvature sensors into textile data gloves is essential to enhance user experience with greater flexibility and adaptability, particularly in various human-machine interface scenarios, including rehabilitation tasks. Current options for such sensors are limited, often relying on strain variance measurements that can introduce significant errors due to stretching interference. Here, the proposed ultra-soft curvature sensor, composed of a soft elastomer and conductive liquid, directly measures curvature with minimal stretching interference, ensuring high performance and reliability. The sensor's microchannel design with embedded nylon ropes and utilizable storage regions provides a wide detection range (0 degrees-180 degrees), low hysteresis (2.46%), and high stability (loading: 3.28%, unloading: 4.29%). This study also presents a data glove integrating flexible curvature sensors and an embedded light-trigger system, aimed at optimizing the human-machine interaction experience through active signal feedback. The design, incorporating real-time feedback mechanisms, is expected to promote physical recovery and a psychological sense of belonging among patients, thereby advancing their autonomy and confidence.
Flexible sensors play a crucial role in enhancing information transmission and human-machine control efficiency, particularly in challenging environments such as nighttime or dusty conditions encountered in counter-te...
详细信息
Flexible sensors play a crucial role in enhancing information transmission and human-machine control efficiency, particularly in challenging environments such as nighttime or dusty conditions encountered in counter-terrorism operations. Combining high stability sensing performance and exceptional flexibility is paramount for effective human-machine interaction facilitated by flexible sensors. Finding a balance between high flexibility, wide detection range, and stability is challenging because they are mutually limiting. In this study, a latex-polyester core-spun elastic yarn with a double-helix structure was used, using a dip-coating process to apply two layers of MWCNTs and one layer of PEDOT:PSS, aiming to enhance the detection range and stability of sensors. The developed yarn sensor exhibited a low modulus (0.09 MPa), a wide detection range (0.025%-200%), and high stability (>20000 cycles). Its flexibility surpassed that of human skin, demonstrating excellent stability under varying rates, strain ranges, and sample lengths. integration of the yarn sensor into sensing gloves facilitated natural gesture recognition in counter-terrorism operations and enabled successful control of unmanned counter-terrorism vehicles, thereby enhancing human-machine interaction. This innovative solution presents significant potential for enhancing the efficiency and accuracy of counter-terrorism operations through improved sensing capabilities.
暂无评论