Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (269)

Search Parameters:
Keywords = flexible chemical sensor

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
14 pages, 2050 KiB  
Article
Electrospun PANI/PEO-Luffa Cellulose/TiO2 Nanofibers: A Sustainable Biocomposite for Conductive Applications
by Gözde Konuk Ege, Merve Bahar Okuyucu and Özge Akay Sefer
Polymers 2025, 17(14), 1989; https://doi.org/10.3390/polym17141989 - 20 Jul 2025
Viewed by 430
Abstract
Herein, electrospun nanofibers composed of polyaniline (PANI), polyethylene oxide (PEO), and Luffa cylindrica (LC) cellulose, reinforced with titanium dioxide (TiO2) nanoparticles, were synthesized via electrospinning to investigate the effect of TiO2 nanoparticles on PANI/PEO/LC nanocomposites and the effect of conductivity [...] Read more.
Herein, electrospun nanofibers composed of polyaniline (PANI), polyethylene oxide (PEO), and Luffa cylindrica (LC) cellulose, reinforced with titanium dioxide (TiO2) nanoparticles, were synthesized via electrospinning to investigate the effect of TiO2 nanoparticles on PANI/PEO/LC nanocomposites and the effect of conductivity on nanofiber morphology. Cellulose extracted from luffa was added to the PANI/PEO copolymer solution, and two different ratios of TiO2 were mixed into the PANI/PEO/LC biocomposite. The morphological, vibrational, and thermal characteristics of biocomposites were systematically investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). As anticipated, the presence of TiO2 enhanced the electrical conductivity of biocomposites, while the addition of Luffa cellulose further improved the conductivity of the cellulose-based nanofibers. FTIR analysis confirmed chemical interactions between Luffa cellulose and PANI/PEO matrix, as evidenced by the broadening of the hydroxyl (OH) absorption band at 3500–3200 cm−1. Additionally, the emergence of characteristic peaks within the 400–1000 cm−1 range in the PANI/PEO/LC/TiO2 spectra signified Ti–O–Ti and Ti–O–C vibrations, confirming the incorporation of TiO2 into the biocomposite. SEM images of the biocomposites reveal that the thickness of nanofibers decreases by adding Luffa to PANI/PEO nanofibers because of the nanofibers branching. In addition, when blending TiO2 nanoparticles with the PANI/PEO/LC biocomposite, this increment continued and obtained thinner and smother nanofibers. Furthermore, the incorporation of cellulose slightly improved the crystallinity of the nanofibers, while TiO2 contributed to the enhanced crystallinity of the biocomposite according to the XRD and DCS results. Similarly, the TGA results supported the DSC results regarding the increasing thermal stability of the biocomposite nanofibers with TiO2 nanoparticles. These findings demonstrate the potential of PANI/PEO/LC/TiO2 nanofibers for advanced applications requiring conductive and structurally optimized biomaterials, e.g., for use in humidity or volatile organic compound (VOC) sensors, especially where flexibility and environmental sustainability are required. Full article
Show Figures

Figure 1

14 pages, 4370 KiB  
Article
Fabrication of Zwitterionized Nanocellulose/Polyvinyl Alcohol Composite Hydrogels Derived from Camellia Oleifera Shells for High-Performance Flexible Sensing
by Jingnan Li, Weikang Peng, Zhendong Lei, Jialin Jian, Jie Cong, Chenyang Zhao, Yuming Wu, Jiaqi Su and Shuaiyuan Han
Polymers 2025, 17(14), 1901; https://doi.org/10.3390/polym17141901 - 9 Jul 2025
Viewed by 366
Abstract
To address the growing demand for environmentally friendly flexible sensors, here, a composite hydrogel of nanocellulose (NC) and polyvinyl alcohol (PVA) was designed and fabricated using Camellia oleifera shells as a sustainable alternative to petroleum-based raw materials. Firstly, NC was extracted from Camellia [...] Read more.
To address the growing demand for environmentally friendly flexible sensors, here, a composite hydrogel of nanocellulose (NC) and polyvinyl alcohol (PVA) was designed and fabricated using Camellia oleifera shells as a sustainable alternative to petroleum-based raw materials. Firstly, NC was extracted from Camellia oleifera shells and modified with 2-chloropropyl chloride to obtain a nanocellulose-based initiator (Init-NC) for atomic transfer radical polymerization (ATRP). Subsequently, sulfonyl betaine methacrylate (SBMA) was polymerized by Init-NC initiating to yield zwitterion-functionalized nanocellulose (NC-PSBMA). Finally, the NC-PSBMA/PVA hydrogel was fabricated by blending NC-PSBMA with PVA. A Fourier transform infrared spectrometer (FT-IR), proton nuclear magnetic resonance spectrometer (1H-NMR), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), universal mechanical testing machine, and digital source-meter were used to characterize the chemical structure, surface microstructure, and sensing performance. The results indicated that: (1) FT-IR and 1H NMR confirmed the successful synthesis of NC-PSBMA; (2) SEM, TEM, and alternating current (AC) impedance spectroscopy verified that the NC-PSBMA/PVA hydrogel exhibits a uniform porous structure (pore diameter was 1.1737 μm), resulting in significantly better porosity (15.75%) and ionic conductivity (2.652 S·m−1) compared to the pure PVA hydrogel; and (3) mechanical testing combined with source meter testing showed that the tensile strength of the composite hydrogel increased by 6.4 times compared to the pure PVA hydrogel; meanwhile, it showed a high sensitivity (GF = 1.40, strain range 0–5%; GF = 1.67, strain range 5–20%) and rapid response time (<0.05 s). This study presents a novel approach to developing bio-based, flexible sensing materials. Full article
(This article belongs to the Special Issue Polysaccharide-Based Materials: Developments and Properties)
Show Figures

Graphical abstract

29 pages, 5886 KiB  
Review
Advances in the Applications and Studies of Polyurethane Foam for Flexible Strain Sensors
by Shuai Huang, Guanbing Liu, Ying Sun and Xiacong Zhang
Polymers 2025, 17(13), 1851; https://doi.org/10.3390/polym17131851 - 2 Jul 2025
Viewed by 683
Abstract
Polyurethane (PU) foam, renowned for its structural versatility, elasticity, compressibility, and adaptability, has garnered significant attention for its use in flexible strain sensors due to its capability to detect mechanical deformation. This review presents a comprehensive analysis of both the studies and recent [...] Read more.
Polyurethane (PU) foam, renowned for its structural versatility, elasticity, compressibility, and adaptability, has garnered significant attention for its use in flexible strain sensors due to its capability to detect mechanical deformation. This review presents a comprehensive analysis of both the studies and recent advancements in PU foam-based strain sensors, particularly those incorporating conductive materials. The review begins by examining the chemical composition and structural characteristics of PU foam, followed by a discussion of various fabrication methods and their effects on sensor performance. It also explores the sensing mechanisms, including piezoresistive, piezoelectric, and capacitive effects. Moreover, key applications in motion detection, health monitoring, and environmental and industrial sensing are examined. Finally, the review addresses technological advancements, current challenges, and prospects. Full article
(This article belongs to the Special Issue Advances in Functional Rubber and Elastomer Composites, 3rd Edition)
Show Figures

Figure 1

13 pages, 2748 KiB  
Article
Polyaniline/Tungsten Disulfide Composite for Room-Temperature NH3 Detection with Rapid Response and Low-PPM Sensitivity
by Kuo Zhao, Yunbo Shi, Haodong Niu, Qinglong Chen, Jinzhou Liu, Bolun Tang and Canda Zheng
Sensors 2025, 25(13), 3948; https://doi.org/10.3390/s25133948 - 25 Jun 2025
Viewed by 347
Abstract
Polyaniline (PANI) is an important conductive-polymer gas-sensing material with working temperature and mechanical flexibilities superior to those of conventional metal oxide sensing materials. However, its applicability is limited by its low sensitivity, high detection limits, and long response/recovery times. In this study, we [...] Read more.
Polyaniline (PANI) is an important conductive-polymer gas-sensing material with working temperature and mechanical flexibilities superior to those of conventional metal oxide sensing materials. However, its applicability is limited by its low sensitivity, high detection limits, and long response/recovery times. In this study, we prepared PANI/WS2 composites via chemical oxidative polymerization and mechanical blending. A multilayer sensor structure—sequentially printed silver-paste heating electrodes, fluorene polyester insulating layer, silver interdigitated electrodes, and sensing material layer—was fabricated on a polyimide substrate via flexible microelectronic printing and systematically characterized using scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The optimized 5 wt% WS2 composite showed enhanced gas-sensing performance, with 219.1% sensitivity to 100 ppm ammonia (2.4-fold higher than that of pure PANI) and reduced response and recovery times of 24 and 91 s, respectively (compared to 81 and 436 s for pure PANI, respectively). Notably, the PANI/WS2 sensor detected an ultralow ammonia concentration (100 ppb) with 0.104% sensitivity. The structural characterization and performance analysis results were used to deduce a mechanism for the enhanced sensing capability. These findings highlight the application potential of PANI/WS2 composites in flexible gas sensors and provide fundamental insights for PANI-based sensing materials research. Full article
(This article belongs to the Section Chemical Sensors)
Show Figures

Figure 1

68 pages, 2430 KiB  
Review
Unlocking the Future: Carbon Nanotubes as Pioneers in Sensing Technologies
by Nargish Parvin, Sang Woo Joo, Jae Hak Jung and Tapas K. Mandal
Chemosensors 2025, 13(7), 225; https://doi.org/10.3390/chemosensors13070225 - 21 Jun 2025
Cited by 1 | Viewed by 928
Abstract
Carbon nanotubes (CNTs) have emerged as pivotal nanomaterials in sensing technologies owing to their unique structural, electrical, and mechanical properties. Their high aspect ratio, exceptional surface area, excellent electrical conductivity, and chemical tunability enable superior sensitivity and rapid response in various sensor platforms. [...] Read more.
Carbon nanotubes (CNTs) have emerged as pivotal nanomaterials in sensing technologies owing to their unique structural, electrical, and mechanical properties. Their high aspect ratio, exceptional surface area, excellent electrical conductivity, and chemical tunability enable superior sensitivity and rapid response in various sensor platforms. This review presents a comprehensive overview of recent advancements in CNT-based sensors, encompassing both single-walled (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). We discuss their functional roles in diverse sensing applications, including gas sensing, chemical detection, biosensing, and pressure/strain monitoring. Particular emphasis is placed on the mechanisms of sensing, such as changes in electrical conductivity, surface adsorption phenomena, molecular recognition, and piezoresistive effects. Furthermore, we explore strategies for enhancing sensitivity and selectivity through surface functionalization, hybrid material integration, and nanostructuring. The manuscript also covers the challenges of reproducibility, selectivity, and scalability that hinder commercial deployment. In addition, emerging directions such as flexible and wearable CNT-based sensors, and their role in real-time environmental, biomedical, and structural health monitoring systems, are critically analyzed. By outlining both current progress and existing limitations, this review underscores the transformative potential of CNTs in the design of next-generation sensing technologies across interdisciplinary domains. Full article
(This article belongs to the Special Issue Application of Carbon Nanotubes in Sensing)
Show Figures

Figure 1

17 pages, 8128 KiB  
Article
Tuning Polymer–Metal Interfaces via Solvent-Engineered Electroless Nickel Coatings on Functional Fibres
by Chenyao Wang, Heng Zhai, Xuzhao Liu, David Lewis, Yuhao Huang, Ling Ai, Xinyi Guan, Hugh Gong, Xuqing Liu and Anura Fernando
Polymers 2025, 17(12), 1693; https://doi.org/10.3390/polym17121693 - 18 Jun 2025
Viewed by 412
Abstract
Electroless nickel deposition (ELD) on polymer substrates enables the fabrication of flexible, conductive fibres for wearable and functional textiles. However, achieving uniform, low-defect coatings on synthetic fibres such as nylon-6,6 remains challenging due to their chemical inertness, hydrophobicity, and poor interfacial compatibility with [...] Read more.
Electroless nickel deposition (ELD) on polymer substrates enables the fabrication of flexible, conductive fibres for wearable and functional textiles. However, achieving uniform, low-defect coatings on synthetic fibres such as nylon-6,6 remains challenging due to their chemical inertness, hydrophobicity, and poor interfacial compatibility with metal coatings. This study presents a solvent-assisted approach using dimethyl sulfoxide (DMSO) in a conventional aqueous ELD bath to control both polymer–metal interfacial chemistry and nickel coating microstructure. The modified surface supports dense catalytic sites, triggering spatially uniform Ni nucleation. The combination of scanning electron microscopy and transmission electron microscopy confirms the difference in coarse grains with fully aqueous baths to a nanocrystalline shell with DMSO-modified baths. This refined microstructure relieves residual stress and anchors firmly to the swollen polymer, delivering +7 °C higher onset decomposition temperature and 45% lower creep strain at 50 °C compared with aqueous controls. The fabric strain sensor fabricated by 1 wt.% DMSO-modified ELD shows a remarkable sensitivity against strain, demonstrating a 1400% resistance change under 200% stain. Electrochemical impedance and polarisation tests confirm a two-fold rise in charge transfer resistance and negligible corrosion current drift after accelerated ageing. By clarifying how a polar aprotic co-solvent couples polymer swelling with metal growth kinetics, the study introduces a scalable strategy for tuning polymer–metal interfaces and advances solvent-assisted ELD as a route to mechanically robust, thermally stable, and corrosion-resistant conductive textiles. Full article
(This article belongs to the Special Issue Polymer Modification for Soft Matter and Flexible Devices)
Show Figures

Figure 1

15 pages, 11557 KiB  
Article
Toward Versatile Transient Electronics: Electrospun Biocompatible Silk Fibroin/Carbon Quantum Dot-Based Green-Emission, Water-Soluble Piezoelectric Nanofibers
by Zhipei Xia, Chubao Liu, Juan Li, Biyao Huang, Chu Pan, Yu Lai, Zhu Liu, Dongling Wu, Sen Liang, Xuanlun Wang, Weiqing Yang and Jun Lu
Polymers 2025, 17(11), 1579; https://doi.org/10.3390/polym17111579 - 5 Jun 2025
Viewed by 562
Abstract
The rapid development of wearable electronics requires multifunctional, transient electronic devices to reduce the ecological footprint and ensure data security. Unfortunately, existing transient electronic materials need to be degraded in chemical solvents or body fluids. Here, we report green luminescent, water-soluble, and biocompatible [...] Read more.
The rapid development of wearable electronics requires multifunctional, transient electronic devices to reduce the ecological footprint and ensure data security. Unfortunately, existing transient electronic materials need to be degraded in chemical solvents or body fluids. Here, we report green luminescent, water-soluble, and biocompatible piezoelectric nanofibers developed by electrospinning green carbon quantum dots (G-CQDs), mulberry silk fibroin (SF), and polyvinyl alcohol (PVA). The introduction of G-CQDs significantly enhances the piezoelectric output of silk fibroin-based fiber materials. Meanwhile, the silk fibroin-based hybrid fibers maintain the photoluminescent response of G-CQDs without sacrificing valuable biocompatibility. Notably, the piezoelectric output of a G-CQD/PVA/SF fiber-based nanogenerator is more than three times higher than that of a PVA/SF fiber-based nanogenerator. This is one of the highest levels of state-of-the-art piezoelectric devices based on biological organic materials. As a proof of concept, in the actual scenario of a rope skipping exercise, the G-CQD/PVA/SF fiber-based nanogenerator is further employed as a self-powered wearable sensor for real-time sensing of athletic motions. It demonstrates high portability, good flexibility, and stable piezoresponse for smart sports applications. This class of water-disposable, piezo/photoactive biological materials could be compelling building blocks for applications in a new generation of versatile, transient, wearable/implantable devices. Full article
(This article belongs to the Special Issue Polymer-Based Wearable Electronics)
Show Figures

Figure 1

19 pages, 4994 KiB  
Article
Optical Ammonia Sensors Based on Spray-Coated Polyaniline Complexes with Polysulfonic Acids
by O. L. Gribkova, V. A. Kabanova, E. I. Rodina, M. A. Teplonogova, L. I. Demina and A. A. Nekrasov
Sensors 2025, 25(11), 3348; https://doi.org/10.3390/s25113348 - 26 May 2025
Viewed by 381
Abstract
The optical ammonia-sensing properties of water-dispersible polyaniline (PANI) complexes chemically synthesized in the presence of polysulfonic acids of different structure and chain flexibility were compared for the first time. Flexible-chain poly(styrene-4-sulfonic acid) and poly-(2-acrylamido-2-methyl-1-propanesulfonic acid), as well as semi-rigid-chain poly-4,4′-(2,2′-disulfonic acid)diphenylene-iso-phthalamide and rigid-chain [...] Read more.
The optical ammonia-sensing properties of water-dispersible polyaniline (PANI) complexes chemically synthesized in the presence of polysulfonic acids of different structure and chain flexibility were compared for the first time. Flexible-chain poly(styrene-4-sulfonic acid) and poly-(2-acrylamido-2-methyl-1-propanesulfonic acid), as well as semi-rigid-chain poly-4,4′-(2,2′-disulfonic acid)diphenylene-iso-phthalamide and rigid-chain poly-4,4′-(2,2′-disulfonic acid)diphenylene-tere-phthalamide (t-PASA) were used. The sensor films were prepared by a convenient and scalable method—spray coating of aqueous solutions on glass substrates. The optical response time and amplitude of the sensor films in the range of ammonia concentrations from 5 to 200 ppm were investigated. To overcome the influence of humidity and presence of over-stoichiometric protons of the polyacid on the accuracy of ammonia determination treatments of the films in aqueous solutions of NaCl, CaCl2 and BaCl2 were tested. The treatment in 1 M CaCl2 solution for all of the PANI complexes results in a significant improvement in the response time, amplitude and reproducibility. The films of PANI complexes with the flexible-chain polyacids have the highest response amplitude in the range of ammonia concentrations 5–25 ppm. PANI-t-PASA film demonstrated the best sensory properties at ammonia concentrations more than 50 ppm. FTIR spectroscopy showed that CaCl2 treatment results in cross-linking of sulfoacid groups from adjacent polyacid chains by Ca2+ ions. Thus, such a treatment results both in the neutralization of excessive protons and a significant reduction in the films’ swelling at high humidity. Full article
(This article belongs to the Special Issue Recent Advances in Sensors for Chemical Detection Applications)
Show Figures

Graphical abstract

29 pages, 2756 KiB  
Review
Flexible Epidermal Sensor Power Systems: Innovations in Multidimensional Materials and Biomedical Applications
by Sheng Zhang, Shulan Zhou, Zhaotao He, Oresegun Olakunle Ibrahim, Chen Liu, Mengwei Wu, Chunge Wang and Qianqian Wang
Sensors 2025, 25(10), 3177; https://doi.org/10.3390/s25103177 - 18 May 2025
Viewed by 629
Abstract
Epidermal sensors are pivotal components of next-generation wearable technologies. They offer transformative potential in health monitoring, motion tracking, and biomedical applications. This potential stems from their ultra-thin design, skin compatibility, and ability to continuously detect physiological signals. The long-term functionality relies on advanced [...] Read more.
Epidermal sensors are pivotal components of next-generation wearable technologies. They offer transformative potential in health monitoring, motion tracking, and biomedical applications. This potential stems from their ultra-thin design, skin compatibility, and ability to continuously detect physiological signals. The long-term functionality relies on advanced power systems balancing flexibility, energy density, and environmental resilience. This review highlights four key power strategies: chemical batteries, biofuel cells, environmental energy harvesters, and wireless power transfer. Breakthroughs in multidimensional materials address challenges in ion transport, catalytic stability, and mechanical durability. Structural innovations mitigate issues like dendrite growth and enzyme degradation. These systems enable applications spanning biomarker analysis, motion sensing, and environmental monitoring. By integrating these advancements, this review concludes with a prospective outlook on future directions for epidermal sensor power systems. Full article
(This article belongs to the Special Issue Advances in Energy Harvesting and Sensor Systems)
Show Figures

Figure 1

16 pages, 1919 KiB  
Article
Multi-Parametric Electrochemical Sensing Platform: Applications in Animal Welfare
by C. Ferreira, E. Lynch, A. O’Herlihy, F. Barry, L. C. Nagle, S. R. Teixeira and P. Galvin
Biosensors 2025, 15(5), 304; https://doi.org/10.3390/bios15050304 - 10 May 2025
Viewed by 566
Abstract
The rapid growth of the dairy sector requires advanced monitoring tools to ensure sustainable practices that benefit the environment, economy, and human health. Current monitoring devices often lack multi-parametric capabilities, limiting their ability to provide comprehensive data on critical chemical and biochemical parameters. [...] Read more.
The rapid growth of the dairy sector requires advanced monitoring tools to ensure sustainable practices that benefit the environment, economy, and human health. Current monitoring devices often lack multi-parametric capabilities, limiting their ability to provide comprehensive data on critical chemical and biochemical parameters. To address this challenge, this work presented the integration of a real-time multi-parametric device with sensors for pH, temperature, nitrate, and nitrite, providing a comprehensive solution to dairy cattle health monitoring. This solution included an electrochemical platform, Portable Unit for Lab-on-Site Electrochemistry (PULSE), and an application for data processing and display. In-house fabricated flexible gold-printed electrodes demonstrated accurate detection of nitrite and nitrate when integrated with the PULSE, achieving sensitivities of 6.32 μA/ppm/cm2 in artificial interstitial fluid and 1.92 μA/ppm/cm2 in phosphate buffered saline, respectively. The PULSE achieved 65.83% and 58.3% lower limits of detection in phosphate buffered saline than a benchtop potentiostat, for nitrate and nitrite, respectively, along with a 24.5% increase in nitrite sensitivity, enhancing its ability to detect lower analyte concentrations. pH sensing was carried out with a commercial screen-printed electrode coated with a layer of iridium oxide. The pH was tested in ruminal complex fluid, obtaining a pH sensitivity of −59.63 mV/pH and an accuracy of 98.9%. These findings highlighted the potential of this technology as an effective tool for dairy cattle health monitoring and its deployment in real-world scenarios. Full article
Show Figures

Figure 1

33 pages, 4065 KiB  
Review
Conducting Polymers-Based Gas Sensors: Principles, Materials, and Applications
by Rongqing Dong, Mingna Yang, Yinxiu Zuo, Lishan Liang, Huakun Xing, Xuemin Duan and Shuai Chen
Sensors 2025, 25(9), 2724; https://doi.org/10.3390/s25092724 - 25 Apr 2025
Viewed by 4033
Abstract
Conducting polymers (CPs) have emerged as promising materials for gas sensors due to their organic nature coupled with unique and versatile optical, electrical, chemical, and electrochemical properties. This review provides a comprehensive overview of the latest developments in conducting polymer-based gas sensors. First, [...] Read more.
Conducting polymers (CPs) have emerged as promising materials for gas sensors due to their organic nature coupled with unique and versatile optical, electrical, chemical, and electrochemical properties. This review provides a comprehensive overview of the latest developments in conducting polymer-based gas sensors. First, the fundamental gas sensing mechanisms in CPs-based sensors are elucidated, covering diverse transduction modes including electrochemical, chemiresistive, optical, piezoelectric, and field-effect transistor-based sensing. Next, the various types of conducting polymers employed in gas sensors, such as polypyrrole, polyaniline, polythiophene, and their composites are introduced, with emphasis on their synthesis methods, structural characteristics, and gas sensing response properties. Finally, the wide range of applications of these sensors is discussed, spanning industrial process control, environmental monitoring, food safety, biomedical diagnosis, and other fields, as well as existing issues such as long-term stability and humidity interference, and a summary of the biocompatibility and regulatory standards of these conductive polymers is provided. By integrating insights from sensing mechanisms, materials, and applications, this review offers a holistic understanding of CPs-based gas sensors. It also highlights future research directions, including device miniaturization, AI-assisted gas identification, multifunctional integrated sensing systems, wearable and flexible sensor platforms, and enhanced sensitivity, selectivity, and on-site detection capabilities. Full article
(This article belongs to the Special Issue Recent Advances in Sensors for Chemical Detection Applications)
Show Figures

Figure 1

14 pages, 1340 KiB  
Article
An Innovative Real-Time Cell Viability Analysis: A Cutting-Edge Flexible Bioimpedance Sensor
by Thien-Luan Phan, Hsin-Yu Chou, Hui-Xuan Huang, Chia-Hung Kuo, Congo Tak Shing Ching and Hui-Min David Wang
Chemosensors 2025, 13(4), 132; https://doi.org/10.3390/chemosensors13040132 - 6 Apr 2025
Viewed by 755
Abstract
There are many compounds used to treat cancer, but still, only 20% of proposed anticancer agents have been commercialized after clinical trials due to serious side effects and unsatisfactory results. To screen potential drugs precisely and quickly, this study develops a flexible bioimpedance [...] Read more.
There are many compounds used to treat cancer, but still, only 20% of proposed anticancer agents have been commercialized after clinical trials due to serious side effects and unsatisfactory results. To screen potential drugs precisely and quickly, this study develops a flexible bioimpedance sensor. The sensor positively detects the half maximal inhibitory concentration (IC50) of drugs in real time by analyzing phase angle changes during cell mortality. The best results are achieved using a probe separation of A12B34 at logarithmic frequencies of 163 Hz and 77.87 kHz. At these two frequencies, there is a linear relationship with the phase angle at 0% and 50% of the dead cells. Dividing the phase angle at the two frequencies shows a 17.98% change in the phase angle, which allows self-correction and insensitivity to the number of cells. A custom phase angle measurement device is developed for detection at 163 Hz and 77.87 kHz, respectively. This study develops a novel sensor that is precise and fast and allows high-throughput analysis to detect the inhibition of cancer in real time. This sensor is an alternative to traditional chemical detection methods because it is faster, cheaper, and more accurate. Full article
Show Figures

Figure 1

54 pages, 19999 KiB  
Review
Hydrogel-Based Continuum Soft Robots
by Honghong Wang, Jingli Du and Yi Mao
Gels 2025, 11(4), 254; https://doi.org/10.3390/gels11040254 - 27 Mar 2025
Cited by 4 | Viewed by 2790
Abstract
This paper comprehensively reviews the latest advances in hydrogel-based continuum soft robots. Hydrogels exhibit exceptional flexibility and adaptability compared to traditional robots reliant on rigid structures, making them ideal as biomimetic robotic skins and platforms for constructing highly accurate, real-time responsive sensory interfaces. [...] Read more.
This paper comprehensively reviews the latest advances in hydrogel-based continuum soft robots. Hydrogels exhibit exceptional flexibility and adaptability compared to traditional robots reliant on rigid structures, making them ideal as biomimetic robotic skins and platforms for constructing highly accurate, real-time responsive sensory interfaces. The article systematically summarizes recent research developments across several key dimensions, including application domains, fabrication methods, actuator technologies, and sensing mechanisms. From an application perspective, developments span healthcare, manufacturing, and agriculture. Regarding fabrication techniques, the paper extensively explores crosslinking methods, additive manufacturing, microfluidics, and other related processes. Additionally, the article categorizes and thoroughly discusses various hydrogel-based actuators responsive to solute/solvent variations, pH, chemical reactions, temperature, light, magnetic fields, electric fields, hydraulic/electro-osmotic stimuli, and humidity. It also details the strategies for designing and implementing diverse sensors, including strain, pressure, humidity, conductive, magnetic, thermal, gas, optical, and multimodal sensors. Finally, the paper offers an in-depth discussion of the prospective applications of hydrogel-based continuum soft robots, particularly emphasizing their potential in medical and industrial fields. Concluding remarks include a forward-looking outlook highlighting future challenges and promising research directions. Full article
Show Figures

Graphical abstract

18 pages, 5121 KiB  
Article
Understanding the Design and Sensory Behaviour of Graphene-Impregnated Textile-Based Piezoresistive Pressure Sensors
by Md Faisal Mahmud, Md Raju Ahmed, Prasad Potluri and Anura Fernando
Sensors 2025, 25(7), 2000; https://doi.org/10.3390/s25072000 - 22 Mar 2025
Viewed by 900
Abstract
Graphene-based textile pressure sensors are emerging as promising candidates for wearable sensing applications due to their high sensitivity, mechanical flexibility, and low energy consumption. This study investigates the design, fabrication, and electromechanical behaviour of graphene-coated nonwoven textile-based piezoresistive pressure sensors, focusing on the [...] Read more.
Graphene-based textile pressure sensors are emerging as promising candidates for wearable sensing applications due to their high sensitivity, mechanical flexibility, and low energy consumption. This study investigates the design, fabrication, and electromechanical behaviour of graphene-coated nonwoven textile-based piezoresistive pressure sensors, focusing on the impact of different electrode materials and fabrication techniques. Three distinct sensor fabrication methods—drop casting, electrospinning, and electro-spraying—were employed to impregnate graphene onto nonwoven textile substrates, with silver-coated textile electrodes integrated to enhance conductivity. The fabricated sensors were characterised for their morphology (SEM), chemical composition (FTIR), and electromechanical response under cyclic compressive loading. The results indicate that the drop-cast sensors exhibited the lowest initial resistance (~0.15 kΩ) and highest sensitivity (10.5 kPa−1) due to their higher graphene content and superior electrical connectivity. Electro-spun and electro-sprayed sensors demonstrated increased porosity and greater resistance fluctuations, highlighting the role of fabrication methods in sensor performance. Additionally, the silver-coated knitted electrodes provided the most stable electrical response, while spun-bonded and powder-bonded nonwoven electrodes exhibited higher hysteresis and resistance drift. These findings offer valuable insights into the optimisation of graphene-based textile pressure sensors for wearable health monitoring and smart textile applications, paving the way for scalable, low-power sensing solutions. Full article
(This article belongs to the Section Chemical Sensors)
Show Figures

Figure 1

23 pages, 5287 KiB  
Article
Humidity- and Temperature-Sensing Properties of 2D-Layered Tungsten Di-Selenide (2H-WSe2) Electroconductive Coatings for Cotton-Based Smart Textiles
by Valentina Trovato, Rajashree Konar, Eti Teblum, Paolo Lazzaroni, Valerio Re, Giuseppe Rosace and Gilbert Daniel Nessim
Polymers 2025, 17(6), 752; https://doi.org/10.3390/polym17060752 - 12 Mar 2025
Cited by 1 | Viewed by 1998
Abstract
Electroconductive textiles (e-Textiles) are vital in developing wearable sensors that preserve the comfort and characteristics of textiles. Among two-dimensional (2D) transition metal dichalcogenides (TMDs), considered a promising option for sensor applications, tungsten di-selenide (WSe2) homostructures have been used as humidity- and [...] Read more.
Electroconductive textiles (e-Textiles) are vital in developing wearable sensors that preserve the comfort and characteristics of textiles. Among two-dimensional (2D) transition metal dichalcogenides (TMDs), considered a promising option for sensor applications, tungsten di-selenide (WSe2) homostructures have been used as humidity- and temperature-sensing materials for developing e-textiles, as mentioned in a first-of-its-kind report. Exfoliated chemical vapor deposition (CVD)-grown 2H-WSe2 nanosheets were dispersed in hydroalcoholic solutions using an amino-functionalized silane to improve dispersion. Acrylic thickener was added to create 2H-WSe2-based pastes, which were applied onto cotton using the knife-over-roll technique to obtain thin, flexible electroconductive coatings on textiles. Various characterization techniques confirmed the even distribution of 2D-WSe2-based coatings on fabrics and the maintenance of textile comfort and wearability. The conductivity of coated fabrics was measured at room temperature and ranged between 2.9 × 108 and 1.6 × 109 Ω sq−1. The WSe2-based textile sensors functioned well as resistance humidity detectors within 30–90% relative humidity (RH), revealing good repeatability and sensitivity after multiple exposure cycles. To a lesser extent, WSe2-based textile sensors act as temperature detectors within 20–60 °C with limited repeatability. The 2D-based textiles exhibited a quadratic dependence of resistance on temperature and a characteristic thermal hysteresis. This proposed strategy marks a significant milestone in developing scalable and flexible 2D TMD-based detectors with great potential for wearable sensing devices. Full article
Show Figures

Graphical abstract

Back to TopTop