Pub Date : 2025-02-12DOI: 10.1016/j.sna.2025.116318
Mohammad Okour , Hamed Nikfarjam , Mutaz Al Fayad , Farahnaz Fallah Tafti , Mohammad Ali Takallou , Iraklis I. Pipinos , Siavash Pourkamali , Sara Myers , Fadi Alsaleem
Microelectromechanical Systems (MEMS) reservoir computers (RC) utilize the vibration of micromechanical structures to perform computing rather than relying on digital computers, enabling low-power computing solutions. This paper introduces a novel application of MEMS RC for classifying the signals of patients with peripheral artery disease (PAD) versus healthy individuals. Using acceleration signals from PAD and non-PAD subjects, this study implements a MEMS RC model with three interconnected MEMS devices, achieving 89 % classification accuracy—substantially outperforming the 54 % accuracy obtained with a single MEMS device. This method reintroduces the benefits of parallel computing to RC, unlike the virtual-node RC approach, which uses one physical system in a serial setup, potentially introducing delays and requiring complex circuitry for high-speed sampling.
{"title":"A MEMS network operating as a reservoir computer to classify peripheral artery disease signal from a healthy signal","authors":"Mohammad Okour , Hamed Nikfarjam , Mutaz Al Fayad , Farahnaz Fallah Tafti , Mohammad Ali Takallou , Iraklis I. Pipinos , Siavash Pourkamali , Sara Myers , Fadi Alsaleem","doi":"10.1016/j.sna.2025.116318","DOIUrl":"10.1016/j.sna.2025.116318","url":null,"abstract":"<div><div>Microelectromechanical Systems (MEMS) reservoir computers (RC) utilize the vibration of micromechanical structures to perform computing rather than relying on digital computers, enabling low-power computing solutions. This paper introduces a novel application of MEMS RC for classifying the signals of patients with peripheral artery disease (PAD) versus healthy individuals. Using acceleration signals from PAD and non-PAD subjects, this study implements a MEMS RC model with three interconnected MEMS devices, achieving 89 % classification accuracy—substantially outperforming the 54 % accuracy obtained with a single MEMS device. This method reintroduces the benefits of parallel computing to RC, unlike the virtual-node RC approach, which uses one physical system in a serial setup, potentially introducing delays and requiring complex circuitry for high-speed sampling.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"385 ","pages":"Article 116318"},"PeriodicalIF":4.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-11DOI: 10.1016/j.sna.2025.116285
Xinwang Wang , Ying Cui , Xin Zhang , Huiliang Cao
In order to address the problem of temperature-induced excessive output drift in MEMS gyroscopes, a zero-bias temperature compensation model based on RIME-VMD-PSO-DBN multiple fusion algorithm is developed in this study. The model utilizes RIME to optimize the input parameters in the VMD algorithm and decomposes the temperature drift of MEMS multi-ring disk solid wave gyroscope through RIME-VMD. The temperature drift signal is decomposed into multiple intrinsic mode functions (IMFs), and is classified and processed according to the frequency. The high-frequency noise term, intermediate frequency mixed noise term, and temperature feature term are processed by PSO-DBN and CWT, respectively. Finally, the processed signal is reconstructed by ELM. Experimental results show that under the conditions of −40 ℃ ∼ 60 ℃, the zero bias instability decreases from 78.48°/h to 0.81 °/h, and the angle random walk reduces from 36.2 to 0.15. Under the conditions of 60 ℃ −40 ℃, the zero bias instability declines from 49.32 °/h to 0.98 °/h, and the angle random walk reduces from 47.53to 0.42.
{"title":"Temperature compensation model of MEMS multi-ring disk solid wave gyroscope based on RIME-VMD and PSO-DBN multi fusion algorithm","authors":"Xinwang Wang , Ying Cui , Xin Zhang , Huiliang Cao","doi":"10.1016/j.sna.2025.116285","DOIUrl":"10.1016/j.sna.2025.116285","url":null,"abstract":"<div><div>In order to address the problem of temperature-induced excessive output drift in MEMS gyroscopes, a zero-bias temperature compensation model based on RIME-VMD-PSO-DBN multiple fusion algorithm is developed in this study. The model utilizes RIME to optimize the input parameters in the VMD algorithm and decomposes the temperature drift of MEMS multi-ring disk solid wave gyroscope through RIME-VMD. The temperature drift signal is decomposed into multiple intrinsic mode functions (IMFs), and is classified and processed according to the frequency. The high-frequency noise term, intermediate frequency mixed noise term, and temperature feature term are processed by PSO-DBN and CWT, respectively. Finally, the processed signal is reconstructed by ELM. Experimental results show that under the conditions of −40 ℃ ∼ 60 ℃, the zero bias instability decreases from 78.48°/h to 0.81 °/h, and the angle random walk reduces from 36.2<span><math><mrow><mo>°</mo><mo>/</mo><msqrt><mi>h</mi></msqrt></mrow></math></span> to 0.15<span><math><mrow><mo>°</mo><mo>/</mo><msqrt><mi>h</mi></msqrt></mrow></math></span>. Under the conditions of 60 ℃ −40 ℃, the zero bias instability declines from 49.32 °/h to 0.98 °/h, and the angle random walk reduces from 47.53<span><math><mrow><mo>°</mo><mo>/</mo><msqrt><mi>h</mi></msqrt></mrow></math></span>to 0.42<span><math><mrow><mo>°</mo><mo>/</mo><msqrt><mi>h</mi></msqrt></mrow></math></span>.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"385 ","pages":"Article 116285"},"PeriodicalIF":4.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tin disulfide (SnS2) thin films, prized for their diverse structural and electrical properties, are increasingly explored for practical applications. This study investigates the controlled doping of SnS2 with selected alkali metals (Li, Na, and K) via a spray-coating method to enhance its functionality, particularly in resistive humidity sensing. The deposition process, meticulously designed for uniformity and reproducibility, incorporates precise concentrations of dopants to modulate film characteristics. X-ray diffraction analysis reveals alterations in lattice parameters and crystallite size (increase from 10 nm to 18 nm) due to doping. X-ray photoelectron spectroscopy elucidates shifts in binding energies and stoichiometry changes induced by dopants. Electrical investigations demonstrate semiconductor behavior, with doped films exhibiting reduced resistance and increased capacitance under humidity, which is critical for humidity sensing. Particularly, Li-doped films display a sensitivity of 18.78 pF/ % RH and a response time of 85 seconds, suggesting promising applications in humidity sensing technology. This comprehensive study provides insights into the intricate interplay between dopants and SnS2 properties, paving the way for tailored material design and sensor development.
{"title":"Unveiling growth and characterization of alkali metals-doped SnS2 thin films for resistive humidity sensing","authors":"Imane Radja , Florin Tudorache , Bouhalouane Amrani , M'hamed Guezzoul , Abdelkader Nebatti Ech-Chergui , Ali Sadek Kadari , Kouider Driss-Khodja , Minnam Reddy Vasudeva Reddy , Adjdir Mehdi , Choukry Kamel Bendeddouche , Mohammad Mansoob Khan","doi":"10.1016/j.sna.2025.116308","DOIUrl":"10.1016/j.sna.2025.116308","url":null,"abstract":"<div><div>Tin disulfide (SnS<sub>2</sub>) thin films, prized for their diverse structural and electrical properties, are increasingly explored for practical applications. This study investigates the controlled doping of SnS<sub>2</sub> with selected alkali metals (Li, Na, and K) via a spray-coating method to enhance its functionality, particularly in resistive humidity sensing. The deposition process, meticulously designed for uniformity and reproducibility, incorporates precise concentrations of dopants to modulate film characteristics. X-ray diffraction analysis reveals alterations in lattice parameters and crystallite size (increase from 10 nm to 18 nm) due to doping. X-ray photoelectron spectroscopy elucidates shifts in binding energies and stoichiometry changes induced by dopants. Electrical investigations demonstrate semiconductor behavior, with doped films exhibiting reduced resistance and increased capacitance under humidity, which is critical for humidity sensing. Particularly, Li-doped films display a sensitivity of 18.78 pF/ % RH and a response time of 85 seconds, suggesting promising applications in humidity sensing technology. This comprehensive study provides insights into the intricate interplay between dopants and SnS<sub>2</sub> properties, paving the way for tailored material design and sensor development.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"385 ","pages":"Article 116308"},"PeriodicalIF":4.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-11DOI: 10.1016/j.sna.2025.116309
Minh Long Hoang , Guido Matrella , Paolo Ciampolini
Precise categorization of sleep postures is essential for evaluating overall physical and mental condition. A smart bed was constructed with the microelectromechanical systems (MEMS) accelerometer sensor and an STM 32-bit microcontroller board. This work applies machine learning (ML) methods to acceleration data to accurately categorize four main sleep positions: right side, left side, prone, and supine without any wearable devices. In this work, the efficiency of 9 ML methods is examined. These algorithms include Logistic Regression (LR) with one-vs-rest and multinomial logistic regression types, Linear Discriminant Analysis (LDA), K-Nearest Neighbors Classification (KNN), Classification and Regression Trees (CART), Naive Bayes (NB), Support Vector Machines (SVMs) with one-vs-one and one-vs-rest types, and Random Forest (RF). The best hyperparameters of each model was accomplished, based on GridSearchCV. The K-fold cross-validation with the assessing measurement stability results indicate that the LG-OvR, LDA, and RF models have the best performance, whereas LG-OvR model possesses accuracy rates of almost 99 %. Furthermore, precision, recall and F1-score are calculated with minimum value of 0.95 for all chosen models. The training and test time are also presented for the selected models. This research has important implications for healthcare, sports medicine, and ergonomics, demonstrating the potential of Artificial Intelligence (AI) approaches in improving sleep monitoring methods.
{"title":"Metrological evaluation of contactless sleep position recognition using an accelerometric smart bed and machine learning","authors":"Minh Long Hoang , Guido Matrella , Paolo Ciampolini","doi":"10.1016/j.sna.2025.116309","DOIUrl":"10.1016/j.sna.2025.116309","url":null,"abstract":"<div><div>Precise categorization of sleep postures is essential for evaluating overall physical and mental condition. A smart bed was constructed with the microelectromechanical systems (MEMS) accelerometer sensor and an STM 32-bit microcontroller board. This work applies machine learning (ML) methods to acceleration data to accurately categorize four main sleep positions: right side, left side, prone, and supine without any wearable devices. In this work, the efficiency of 9 ML methods is examined. These algorithms include Logistic Regression (LR) with one-vs-rest and multinomial logistic regression types, Linear Discriminant Analysis (LDA), K-Nearest Neighbors Classification (KNN), Classification and Regression Trees (CART), Naive Bayes (NB), Support Vector Machines (SVMs) with one-vs-one and one-vs-rest types, and Random Forest (RF). The best hyperparameters of each model was accomplished, based on GridSearchCV. The K-fold cross-validation with the assessing measurement stability results indicate that the LG-OvR, LDA, and RF models have the best performance, whereas LG-OvR model possesses accuracy rates of almost 99 %. Furthermore, precision, recall and F1-score are calculated with minimum value of 0.95 for all chosen models. The training and test time are also presented for the selected models. This research has important implications for healthcare, sports medicine, and ergonomics, demonstrating the potential of Artificial Intelligence (AI) approaches in improving sleep monitoring methods.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"385 ","pages":"Article 116309"},"PeriodicalIF":4.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-10DOI: 10.1016/j.sna.2025.116302
Haifeng Se , Kai Song , Jinhai Jiang , Chuanyu Sun , Yuhan Hu , Bo Wang , Lu Xia , Xuanhe Wang , Jijiang Liu
Pattern recognition constitutes a critical building block in machine olfaction. Traditional machine learning methods rely on the response curves from gas sensor arrays. However, it usually takes hundreds of seconds to acquire the entire curves, which significantly increases detection time. Furthermore, manual feature extraction suffers from limitations such as low adaptability and inefficiency. Therefore, a robust and fast gas detection method combining Remaining Response Curve Forecasting (RRCF) and Gas Classification (GC) is proposed. First, the early part of the response curve is used as input, and RRCF predicts the remaining part of the curve. Second, the early part and prediction result are spliced together to reconstruct the response curve. Finally, GC utilizes these reconstructed response curves for gas classification. Experimental results show that RRCF-GC achieves accuracies of 97.58 % and 91.59 % in cross-board and mixed gas scenarios, respectively, under the condition of reducing the detection time by about three-fifths.
{"title":"A robust and fast odor detection method with remaining response curve forecasting","authors":"Haifeng Se , Kai Song , Jinhai Jiang , Chuanyu Sun , Yuhan Hu , Bo Wang , Lu Xia , Xuanhe Wang , Jijiang Liu","doi":"10.1016/j.sna.2025.116302","DOIUrl":"10.1016/j.sna.2025.116302","url":null,"abstract":"<div><div>Pattern recognition constitutes a critical building block in machine olfaction. Traditional machine learning methods rely on the response curves from gas sensor arrays. However, it usually takes hundreds of seconds to acquire the entire curves, which significantly increases detection time. Furthermore, manual feature extraction suffers from limitations such as low adaptability and inefficiency. Therefore, a robust and fast gas detection method combining Remaining Response Curve Forecasting (RRCF) and Gas Classification (GC) is proposed. First, the early part of the response curve is used as input, and RRCF predicts the remaining part of the curve. Second, the early part and prediction result are spliced together to reconstruct the response curve. Finally, GC utilizes these reconstructed response curves for gas classification. Experimental results show that RRCF-GC achieves accuracies of 97.58 % and 91.59 % in cross-board and mixed gas scenarios, respectively, under the condition of reducing the detection time by about three-fifths.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"386 ","pages":"Article 116302"},"PeriodicalIF":4.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, multi-functional actuators have caused concern owing to extensive possible applications in biomimetic and intelligent systems. Nonetheless, traditional light-driven actuators with bilayer heterostructure are mostly unsuitable for wading environments. Also, the heat generated can not be effectively utilized. Hence, there is an urgent demand for the progress of light-powered photothermal actuators which can not only be used in amphibious environments, but also utilize photothermal energy. To fill this gap, we designed amphibious light-powered actuators according to bilayer aluminum/carbon nanotube-polydimethylsiloxane (Al/CNT-PDMS) composite films with heterostructure. First, a light-driven actuator was designed according to the change in coefficient of thermal expansion (CTEs) between the layers. In the near-infrared (NIR) irradiation, its photothermal conversion efficiency could reach over 90 % with a maximum bending angle of 46.27°. Second, a floating light-powered actuator was designed according to the Marangoni Effect with a moving speed up to 16.7 mm s−1. Further, the triboelectric nanogenerator (TENG) made from this composite film achieved an open-circuit voltage of 138 V. Finally, taking advantage of the above characteristics, the Al/CNT-PDMS actuators were used in a series of practical applications towards land and wading environments. These applications including bionic sunflowers, flexible switches, smart curtains, intelligent conveyor belts, and the self-powered light power sensors, demonstrating a broad range of appealing applications.
{"title":"Hierarchical metal/carbon nanotube-polymer composite films for amphibious photothermal actuators and power generation","authors":"Qiaohang Guo , Changsheng Wu , Peidi Zhou , Shiwen Dou , Kaihuai Yang , Huamin Chen , Zi Chen , Mingcen Weng","doi":"10.1016/j.sna.2025.116301","DOIUrl":"10.1016/j.sna.2025.116301","url":null,"abstract":"<div><div>In recent years, multi-functional actuators have caused concern owing to extensive possible applications in biomimetic and intelligent systems. Nonetheless, traditional light-driven actuators with bilayer heterostructure are mostly unsuitable for wading environments. Also, the heat generated can not be effectively utilized. Hence, there is an urgent demand for the progress of light-powered photothermal actuators which can not only be used in amphibious environments, but also utilize photothermal energy. To fill this gap, we designed amphibious light-powered actuators according to bilayer aluminum/carbon nanotube-polydimethylsiloxane (Al/CNT-PDMS) composite films with heterostructure. First, a light-driven actuator was designed according to the change in coefficient of thermal expansion (CTEs) between the layers. In the near-infrared (NIR) irradiation, its photothermal conversion efficiency could reach over 90 % with a maximum bending angle of 46.27°. Second, a floating light-powered actuator was designed according to the Marangoni Effect with a moving speed up to 16.7 mm s<sup>−1</sup>. Further, the triboelectric nanogenerator (TENG) made from this composite film achieved an open-circuit voltage of 138 V. Finally, taking advantage of the above characteristics, the Al/CNT-PDMS actuators were used in a series of practical applications towards land and wading environments. These applications including bionic sunflowers, flexible switches, smart curtains, intelligent conveyor belts, and the self-powered light power sensors, demonstrating a broad range of appealing applications.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"385 ","pages":"Article 116301"},"PeriodicalIF":4.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.sna.2025.116273
Dan Gh. Matei, Daniel Ursescu
An electro-opto-mechanical device based on frustrated total internal reflection is designed and constructed for use in the laser beam power control. It is based on a double prism attenuator and it demonstrates high dynamic range continuous attenuation up to 120 dB. The device is used to actively stabilize the power of a laser beam over a bandwidth of more than 1 kHz. An enhancement of more than one order of magnitude in the power spectral density of the power fluctuations is obtained in closed-loop operation.
{"title":"Laser power stabilization using a double prism attenuator","authors":"Dan Gh. Matei, Daniel Ursescu","doi":"10.1016/j.sna.2025.116273","DOIUrl":"10.1016/j.sna.2025.116273","url":null,"abstract":"<div><div>An electro-opto-mechanical device based on frustrated total internal reflection is designed and constructed for use in the laser beam power control. It is based on a double prism attenuator and it demonstrates high dynamic range continuous attenuation up to 120<!--> <!-->dB. The device is used to actively stabilize the power of a laser beam over a bandwidth of more than 1<!--> <!-->kHz. An enhancement of more than one order of magnitude in the power spectral density of the power fluctuations is obtained in closed-loop operation.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"385 ","pages":"Article 116273"},"PeriodicalIF":4.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.sna.2025.116283
Zixia Yu, Xiaolong Zhao, Yongqing Yue, Danyang Huang, Yongning He
A photoconductive and acoustic dual-mode X-ray dose rate detector based on a GaN single crystal was explored in this work, which utilizing the photoelectric and piezoelectric effects of the GaN semiconductor. The detector was fabricated from a bulk GaN single crystal with a resistivity of 107·Ω·cm, and its resonant frequency in the dark condition is 11.5 MHz, with a high quality factor (Q factor) of 1165. Under X-ray irradiation, the bulk conductivity of the GaN single crystal increases allowing the detector to work at the photoconductive mode. Simultaneously, the reduced wave velocity causes a shift in the resonant frequency of the GaN acoustic resonator enabling working at the acoustic mode. Experimental results show that the detector has the responsivities of nC Gy−1·cm-² and (0.31 ± 0.03) kHz Gy⁻¹ s for the photoconductive and the acoustic modes respectively.
{"title":"Photoconductive and acoustic dual-mode X-ray dose rate detector based on a GaN single crystal","authors":"Zixia Yu, Xiaolong Zhao, Yongqing Yue, Danyang Huang, Yongning He","doi":"10.1016/j.sna.2025.116283","DOIUrl":"10.1016/j.sna.2025.116283","url":null,"abstract":"<div><div>A photoconductive and acoustic dual-mode X-ray dose rate detector based on a GaN single crystal was explored in this work, which utilizing the photoelectric and piezoelectric effects of the GaN semiconductor. The detector was fabricated from a bulk GaN single crystal with a resistivity of 10<sup>7</sup>·Ω·cm, and its resonant frequency in the dark condition is 11.5 MHz, with a high quality factor (Q factor) of 1165. Under X-ray irradiation, the bulk conductivity of the GaN single crystal increases allowing the detector to work at the photoconductive mode. Simultaneously, the reduced wave velocity causes a shift in the resonant frequency of the GaN acoustic resonator enabling working at the acoustic mode. Experimental results show that the detector has the responsivities of nC Gy<sup>−1</sup>·cm<sup>-</sup>² and (0.31 ± 0.03) kHz Gy⁻¹ s for the photoconductive and the acoustic modes respectively.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"384 ","pages":"Article 116283"},"PeriodicalIF":4.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.sna.2025.116300
Issam Ouni, Youssef Moualhi, Hedi Rahmouni
The present investigation highlights the impact of introducing few potassium contents on the electrical and dielectric properties of Pr0.8Na0.2MnO3 mixed valence system. Resistivity curves of Pr0.8Na0.2-xKxMnO3 (x = 0.0 and x = 0.05) manganites have been investigated over a large temperature range between 80 K and 500 K. The studied compounds exhibit a semiconductor behavior. Between 180 K and 400 K, the activation energy values Ea, the thermistor constant β, the sensitivity factor α, and the stability factor SF parameters are calculated to confirm that Pr0.8Na0.2-xKxMnO3 (x = 0.0 and x = 0.05) compounds are suitable candidates for sensor applications. Capacitance measurements as a function of frequency, at various temperatures, are reported for both samples to confirm the strong importance of the microstructure (bulk and grain boundary regions) on the dielectric properties and the capacitive behavior of the manganites. From the capacitance investigation, we found that both prepared ceramics are charactered by motivating and stable capacitance values making those compounds promote applicant in the sector of the ceramic capacitors with Y5R, Y6R, Y7R, and X7P codes.
{"title":"Thermistor and capacitor parameter analysis through electrical and dielectric investigations of manganite systems for technological applications","authors":"Issam Ouni, Youssef Moualhi, Hedi Rahmouni","doi":"10.1016/j.sna.2025.116300","DOIUrl":"10.1016/j.sna.2025.116300","url":null,"abstract":"<div><div>The present investigation highlights the impact of introducing few potassium contents on the electrical and dielectric properties of Pr<sub>0.8</sub>Na<sub>0.2</sub>MnO<sub>3</sub> mixed valence system. Resistivity curves of Pr<sub>0.8</sub>Na<sub>0.2-x</sub>K<sub>x</sub>MnO<sub>3</sub> (x = 0.0 and x = 0.05) manganites have been investigated over a large temperature range between 80 K and 500 K. The studied compounds exhibit a semiconductor behavior. Between 180 K and 400 K, the activation energy values E<sub>a</sub>, the thermistor constant β, the sensitivity factor α, and the stability factor SF parameters are calculated to confirm that Pr<sub>0.8</sub>Na<sub>0.2-x</sub>K<sub>x</sub>MnO<sub>3</sub> (x = 0.0 and x = 0.05) compounds are suitable candidates for sensor applications. Capacitance measurements as a function of frequency, at various temperatures, are reported for both samples to confirm the strong importance of the microstructure (bulk and grain boundary regions) on the dielectric properties and the capacitive behavior of the manganites. From the capacitance investigation, we found that both prepared ceramics are charactered by motivating and stable capacitance values making those compounds promote applicant in the sector of the ceramic capacitors with Y5R, Y6R, Y7R, and X7P codes.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"384 ","pages":"Article 116300"},"PeriodicalIF":4.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.sna.2025.116272
Dalia N. Elsheakh , Mennatullah E. Elsayed , Angie R. Eldamak
This paper is developing a wearable device for breast cancer detection using four elements of circularly polarized (CP) sensors. The proposed CP sensors are integrated as a smart bra to provide a wearable breast cancer detection system. The proposed antenna-based sensor consists of a flexible Roger 3003 substrate with a thickness of 0.17 mm, an etched trapezoidal slot, and a CPW trapezoidal-shaped monopole antenna with an overall compact size of as 0.2 λo × 0.2 λo m2. The proposed sensors provide conformal construction for biological structures and biocompatibility and sufficiently extended bandwidth from 1.8 to 8 GHz at |S11| ≤ −10 dB. To guarantee safety, the specific absorption rate (SAR) of 0.789 W/kg at 20 dBm and 5.8 GHz has been computed and measured for the proposed sensor. CP sensors provide significant advantages in near-field applications compared to linear polarized sensors validated by fidelity parameter calculation and image construction for proposed sensors for image reconstruction applications. This paper also includes an analysis of bending, SAR, and heat effects. Measurements for transmission and reflection parameters without and with tumors at different positions in breast phantom are also recorded and presented
{"title":"Circularly polarized flexible antennas for near field breast cancer sensing in a smart bra monitoring system","authors":"Dalia N. Elsheakh , Mennatullah E. Elsayed , Angie R. Eldamak","doi":"10.1016/j.sna.2025.116272","DOIUrl":"10.1016/j.sna.2025.116272","url":null,"abstract":"<div><div>This paper is developing a wearable device for breast cancer detection using four elements of circularly polarized (CP) sensors. The proposed CP sensors are integrated as a smart bra to provide a wearable breast cancer detection system. The proposed antenna-based sensor consists of a flexible Roger 3003 substrate with a thickness of 0.17 mm, an etched trapezoidal slot, and a CPW trapezoidal-shaped monopole antenna with an overall compact size of as 0.2 λ<sub>o</sub> × 0.2 λ<sub>o</sub> m<sup>2</sup>. The proposed sensors provide conformal construction for biological structures and biocompatibility and sufficiently extended bandwidth from 1.8 to 8 GHz at |S<sub>11</sub>| ≤ −10 dB. To guarantee safety, the specific absorption rate (SAR) of 0.789 W/kg at 20 dBm and 5.8 GHz has been computed and measured for the proposed sensor. CP sensors provide significant advantages in near-field applications compared to linear polarized sensors validated by fidelity parameter calculation and image construction for proposed sensors for image reconstruction applications. This paper also includes an analysis of bending, SAR, and heat effects. Measurements for transmission and reflection parameters without and with tumors at different positions in breast phantom are also recorded and presented</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":"387 ","pages":"Article 116272"},"PeriodicalIF":4.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号