scholarly journals A Fabric-Based Textile Stretch Sensor for Optimized Measurement of Strain in Clothing

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7323
Author(s):  
Yetanawork Teyeme ◽  
Benny Malengier ◽  
Tamrat Tesfaye ◽  
Lieva Van Langenhove
Keyword(s):  
Mechanical Deformation ◽  
Strain Sensors ◽  
Deformation Characteristics ◽  
Good Sensitivity ◽  
Molecular Rearrangement ◽  
Textile Materials ◽  
Conductive Fabric ◽  
Good Working ◽  
Degree Of Orientation ◽  
Potential Use

Fabric stretch sensors are available as planar fabrics, but their reliability and reproducibility are low. To find a good working setup for use in an elastic sports garment, the design of such sensors must be optimized. The main purpose of this study was to develop resistive strain sensors from stretchable conductive fabric and investigating the influence of stretchability on conductivity/resistivity. The influence of using the sensor in a sweat rich environment was also determined, in order to evaluate the potential use of the sensor in sporting garments. The sensor resistivity performance was analyzed for its sensitivity, working range, and repeatability and it was determined what makes the sensitivity when elongated or stretched. The resistivity was found to decrease with elongation if no sweat is present, this can be due to molecular rearrangement and a higher degree of orientation that improves the conductivity of a material. The result from this finding also shows that for wearable applications the commercial EeonTexTM conductive stretchable fabric did not show a considerable resistivity increase, nor a good sensitivity. The sensitivity of the sensor was between 0.97 and 1.28 and varies with different elongation %. This may be due to the mechanical deformation characteristics of knitted samples that lead to changes in conductivity. We advise that the testing performed in this paper is done by default on new stretch sensitive textile materials, so practical use of the material can be correctly estimated.

Production of Miniaturized Sensor Structures on Polymer Substrates Using Inkjet Printing

2014 ◽  
Vol 1038 ◽  
pp. 49-55 ◽  
Author(s):  
Oleksandr Kravchuk ◽  
Kristina Grunewald ◽  
Joachim Bahr ◽  
Florian Hofmann ◽  
Marcus Reichenberger
Keyword(s):  
Inkjet Printing ◽  
Mechanical Deformation ◽  
Strain Sensors ◽  
Performance Tests ◽  
Polymer Substrates ◽  
Surface Conditions ◽  
Grid Line ◽  
Line Widths

Strain sensors based on the resistive principle have been developed and produced by inkjet printing. Depending on the surface conditions of the substrates and the properties of the silver inks, with adequate densification of the printed nanoparticle containing structures, gauge factors of around 2.6, dimensions of 6.7 mm × 6.4 mm and grid line widths of around 90 μm, have been achieved with silver inks. Performance tests including up to 120 mechanical deformation cycles have been successfully carried out.

Shear and Deformation Characteristics of Municipal Waste Combustor Bottom Ash for Highway Applications

1997 ◽  
Vol 1577 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Deborah A. Pandeline ◽  
Paul J. Cosentino ◽  
Edward H. Kalajian ◽  
Mario F. Chavez
Keyword(s):  
Bottom Ash ◽  
Confining Pressure ◽  
Municipal Waste ◽  
Deformation Characteristics ◽  
Angle Of Internal Friction ◽  
Refuse Derived Fuel ◽  
Compaction Energy ◽  
Moisture Conditions ◽  
Potential Use ◽  
Municipal Waste Combustor

Municipal waste combustor (MWC) bottom ash from mass-burn (MB) and refuse-derived-fuel (RDF) facilities was evaluated for potential use as highway fill material. MWC bottom ash exhibits acceptable shear and deformation characteristics for many highway applications. RDF ash contains a lower metals percentage than MB ash. The specific gravity of both ashes was found to be a function of metals content. Moisturedensity relationships and unconfined compressive strengths were found to be a function of compaction energy and moisture content. Allowing compacted ash to age increased its unconfined compressive strength. Stress-strain characteristics of both ashes are similar to those of sands. Cohesion exists possibly because of pozzolonic reactions in the bottom ash. The angle of internal friction increased with compacted density. Elastic moduli are a function of density and confining pressure. RDF ash was found to be twice as stiff as MB ash. California bearing ratio results greater than 100 indicated that MB ash could be utilized as road base, and values between 25 and 95 indicated that RDF would be acceptable for use in subgrade and subbase. Bearing ratio results were highly dependent on moisture conditions. Both ashes exhibit little to no swell and should not cause field problems during saturation.

scholarly journals A New Approach for Monitoring Sweat Ammonia Levels Using a Ventilated Capsule

2021 ◽  
Vol 10 (1) ◽  
pp. 38
Author(s):  
Annemarijn Steijlen ◽  
Jeroen Bastemeijer ◽  
Robbert Nederhoff ◽  
Kaspar Jansen ◽  
Paddy French ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Measurement Range ◽  
Good Sensitivity ◽  
New Approach ◽  
Humidity Effects ◽  
Metabolic Myopathies ◽  
Temperature And Humidity ◽  
Nh3 Sensor ◽  
Metal Oxide Gas Sensor ◽  
Potential Use

Ammonium levels in sweat can potentially be used to measure muscle fatigue and to diagnose particular metabolic myopathies. To research the potential use of ammonia in sweat as a biomarker, a new real-time monitoring system is developed. This system consists of a capsule that is placed on the skin and ventilated with dry air. A metal-oxide gas sensor in the capsule detects the ammonia that is evaporated from sweat. The sensor system was built, and calibration experiments were performed. The sensors show good sensitivity from 27 mV/ppm to 1.1 mV/ppm in the desired measurement range of 1 to 30 ppm, respectively. A temperature and humidity sensor is integrated to compensate for temperature and humidity effects on the NH3 sensor.

scholarly journals Development of flexible textile aluminium-air battery prototype

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Aleksandrs Vališevskis ◽  
Uģis Briedis ◽  
Miguel Carvalho ◽  
Fernando Ferreira
Keyword(s):  
Energy Source ◽  
Storage Time ◽  
Textile Materials ◽  
Active Sensor ◽  
Time Period ◽  
Storage Solutions ◽  
Air Battery ◽  
Cotton Shell ◽  
Main Components ◽  
Potential Use

AbstractThere is one component that virtually any embedded wearable needs—a power source. This paper proposes an energy source, which contains no harmful substances, can be stored in a stand-by dry state for indefinite time period, is flexible and has tactile characteristics similar to that of textile. The main feature of this energy source is the separation of the electrolyte and the electrodes—the electrolyte is applied only when the battery needs to be activated. This makes storage time in a dry state virtually infinite. It expands their potential use to storage solutions and healthcare/health monitoring solutions, because the design of the battery allows it to be used as an active sensor, which generates electric current, when it detects liquid. We stress that this solution is suitable for specific applications only, outlined in the paper. The main components of the battery include aluminium anode, air cathode and the cotton shell. The design includes only textile-based materials, which ensure greater flexibility and better fusion with textile materials, where the battery is intended to be integrated. Besides that, results of the experiments with multi-cell battery prototype are presented.

Mechanical Deformation Characteristics of Hard Rock in Deep Excavation

2011 ◽  
Vol 90-93 ◽  
pp. 61-66 ◽  
Author(s):  
Ying Hui Lv ◽  
Bin Yan
Keyword(s):  
Rock Mass ◽  
Simulation Analysis ◽  
Volumetric Strain ◽  
Mechanical Deformation ◽  
Deformation Characteristics ◽  
Deep Excavation ◽  
Tunnel Excavation ◽  
Failure Characteristics ◽  
Excavation Process ◽  
Coulomb Criterion

In the process of deep tunnel excavation, the surrounding rock mass, which often endures high initial geo-stress, is in the state of typical unloading. As the adjustment of stress induced by excavation, rock mass behaves a peculiar kind of mechanical deformation characteristics, different from those in loading conditions. As thus, a series of representative unloading tests on hard granite from DaGangShan power station in China, which is being excavation at 1500 meters deep below earth surface, are carried out to simulate dynamically excavation process for studying the peculiar mechanical deformation characteristics. On the basis of unloading tests, a series of research results are acquired as follows： (1) Under unloading condition, lateral deformation occurs in the unloading direction and volumetric strain changes from compression deformation to dilation deformation. (2) Under unloading condition, hard granites behave brittle failure and Mogi-coulomb criterion can well describe the failure characteristics. (3) According to curves of unloading tests, the constitutive model is deduced for simulation analysis.

scholarly journals ASSESSMENT OF BED JOINTS BEHAVIOR OF CALCIUM SILICATE BRICK MASONRY DURING EXECUTION

2016 ◽  
Vol 8 (4) ◽  
pp. 143-149 ◽  
Author(s):  
Tomas Šlivinskas ◽  
Bronius Jonaitis ◽  
Łukasz Drobiec
Keyword(s):  
Plastic Deformation ◽  
Compressive Strength ◽  
Composite Material ◽  
Calcium Silicate ◽  
Compressive Load ◽  
Mechanical Deformation ◽  
Deformation Characteristics ◽  
Factors Affecting ◽  
Mortar Strength ◽  
Strength And Deformation

This article examines masonry as the composite material. Factors affecting the mechanical deformation characteristics of masonry bed joints are reviewed. The strength and deformation characteristics of bed joints under the influence of changing mortar strength and variable compressive load are analysed Compressive strength, shrinkage and plastic deformation of masonry fragments and bed joints under variable compressive strength are also examined.

Flexible polypyrrole-coated conductive fabric sensor for large deformation measurement

2019 ◽  
Vol 31 (5) ◽  
pp. 609-618
Author(s):  
Chi Zhang ◽  
Pu Xue ◽  
Yubo Luo
Keyword(s):  
Large Deformation ◽  
Strain Range ◽  
High Sensitivity ◽  
Training System ◽  
Strain Sensors ◽  
Strain Sensing ◽  
Mechanism Study ◽  
Resistance Change ◽  
Content Type ◽  
Conductive Fabric

Purpose Strain sensors have been widely used to measure the strain of the structure. However, the ordinary sensing elements are not suitable for measuring large deformation on an irregular surface, which limits their applications. Recently, flexible sensors have attracted extensive interest because they can overcome the shortage of the ordinary sensing elements. The paper aims to discuss this issue. Design/methodology/approach In this paper, the whole measurement process of strain sensing behavior and the dimension design of fle3xible strain sensing system use the macroscopic measurement method of material tensile test to accurately measure the resistance change with strain. Afterwards, combining electrical components, the flexible strain sensors are produced for two biomedical applications: the wearable data-collecting gloves and rehabilitation training system. Findings The results show that the developed conductive fabric can exhibit high sensitivity, large workable strain range (>50 percent) under simple and repeated tension and good stability. Both applications demonstrate that the polypyrrole-coated fabric sensor can successfully measure the large and repeat strain, capture the motion of body and display corresponding information almost in real time. Originality/value The limitation lies in the lack of a holistic strain sensing mechanism study, and the lack of a corresponding theoretical model to explain the experimental results.

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