scholarly journals DEVELOPMENT AND CHARACTERIZATION OF STITCH-BASED SENSORS

2021 ◽  
Vol 2021 ◽  
pp. 18-25
Author(s):  
S.A. Odhiambo ◽  
S. Vasile ◽  
J. Sarrazyn ◽  
I. Rottiers ◽  
A. De Raeve

Strain sensing seams have been developed by integrating conductive sewing threads in different types of seam designs on a fabric typical for sports clothing using sewing technology. The aim was to obtain a simply integrated stitch-based sensor that can be applied on sports clothing to monitor the movements of the upper body parts of the user during exercising. Stitch types 304; 406; 602 and 605 were produced. The seams were made on a knitted fabric composed of 80% polyamide 6.6 and 20% elastane. The seams underwent stretch cycling for 10 cycles and up to 44 cycles following EN ISO 14704-1:2005 (modified), using an INSTRON tensile tester machine. The changes in the resistance of the seams with time were recorded simultaneously using Agilent meter U1273A. Sensing functionality among which is sensor gauge factor (GF), stability, drift, and reproducibility were evaluated on the promising sensor seams. The type of base fabric used, stitch type, stitch formation process (friction and dynamic forces during sewing), integrated EC thread length, and positioning of thread(s) in the fabric have a significant influence on the performance of the seams. Sensor seam 406-001comprising 2 EC yarns (Madeira HC12) and Sensor seam 304-010 comprising 1 EC yarn (Madeira HC40) turned out to be very promising and others shall be improved (sensor 602-006 with Madeira HC 40 and sensor 605-002 with a Muriel yarn).

1996 ◽  
Vol 74 (S1) ◽  
pp. 151-155
Author(s):  
J. M. Chen ◽  
M. Parameswaran ◽  
M. Paranjape

This paper presents experimental results on the piezoresistance characterization of gate polysilicon available from two commercial CMOS processes. It is shown that the gate polysilicon is very strain-sensitive, and a gauge factor of about 25 can be readily achieved. This value can allow standard gate polysilicon to be used as a strain-sensing element for integrated microsensor applications. As an example, a sub-nanogram mass sensor was fabricated using commercially available CMOS technology and is presented. The device incorporates gate polysilicon of the CMOS process as the sensing material, and is subjected to low levels of strain in order to measure small masses (< 10−9 g). A potential application for this sensor is to monitor the growth of biological cell cultures in a liquid environment.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Roopa Hegde ◽  
Koona Ramji ◽  
Swapna Peravali ◽  
Yallappa Shiralgi ◽  
Gurumurthy Hegde ◽  
...  

Multiwalled carbon nanotubes (MWCNTs) were synthesized by the reduction of ethyl alcohol with sodium borohydride (NaBH4) under a strong basic solvent with the high concentration of sodium hydroxide (NaOH). Nanocomposites of different concentration of MWCNT dispersed in poly(3,4-ethylene dioxythiophene) polymerized with poly(4-styrene sulfonate) (PEDOT:PSS) were prepared and deposited on a flexible polyethylene terephthalate (PET) polymer substrates by the spin coating method. The thin films were characterized for their nanostructure and subsequently evaluated for their piezoresistive response. The films were subjected to an incremental strain from 0 to 6% at speed of 0.2 mm/min. The nanocomposite thin film with 0.1 wt% of MWCNT exhibits the highest gauge factor of 22.8 at 6% strain as well as the highest conductivity of 13.5 S/m. Hence, the fabricated thin film was found to be suitable for piezoresistive flexible strain sensing applications.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhishek Mazumder ◽  
Hrishikesh Choudhury ◽  
Abhinit Dey ◽  
Dandadhar Sarma

AbstractDiseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018 to January 2019). Swabs from the infected body parts were streaked on sterilized nutrient agar. Two dominant bacterial colonies were obtained, which were then isolated and labelled as AM-31 and AM-05. Standard biochemical characterisation and 16S rRNA and rpoB gene sequencing identified AM-31 isolate as Aeromonas hydrophila and AM-05 as Aeromonas jandaei. Symptoms similar to that of natural infection were observed on re-infecting both bacteria to disease-free A. testudineus, which confirmed their virulence. LC50 was determined at 1.3 × 104 (A. hydrophila) and 2.5 × 104 (A. jandaei) CFU per fish in intraperitoneal injection. Further, PCR amplification of specific genes responsible for virulence (aerolysin and enterotoxin) confirmed pathogenicity of both bacteria. Histopathology of kidney and liver in the experimentally-infected fishes revealed haemorrhage, tubular degeneration and vacuolation. Antibiotic profiles were also assessed for both bacteria. To the best of our knowledge, the present work is a first report on the mortality of farmed climbing perch naturally-infected by A. hydrophila as well as A. jandaei, with no records of pathogenicity of the latter in this fish.


2021 ◽  
Author(s):  
Pradeep Lall ◽  
Jinesh Narangaparambil ◽  
Tony Thomas ◽  
Kyle Schulze

Abstract Printed electronics has found new applications in wearable electronics owing to the opportunities for integration, and the ability of sustaining folding, flexing and twisting. Continuous monitoring necessitates the production of sensors, which include temperature, humidity, sweat, and strain sensors. In this paper, a process study was performed on the FR4 board while taking into account multiple printing parameters for the direct-write system. The process parameters include ink pressure, print speed, and stand-off height, as well as their effect on the trace profile and print consistency using white light interferometry analysis. The printed traces have also been studied for different sintering conditions while keeping the FR4 board’s temperature limit in mind. The paper also discusses the effect of sintering conditions on mechanical and electrical properties, specifically shear load to failure and resistivity. The data from this was then used to print strain gauges and compared them to commercially available strain gauges. By reporting the gauge factor, the printed strain gauge has been standardized. The conductive ink’s strain sensing capabilities will be studied under tensile cyclic loading (3-point bending) at various strain rates and maximum strains. Long-term performance testing will be carried out using cyclic tensile loads.


2021 ◽  
Vol 9 (4) ◽  
pp. 55
Author(s):  
Joshua Mallen ◽  
Manisha Kalsan ◽  
Peyman Zarrineh ◽  
Laure Bridoux ◽  
Shandar Ahmad ◽  
...  

The highly conserved HOX homeodomain (HD) transcription factors (TFs) establish the identity of different body parts along the antero–posterior axis of bilaterian animals. Segment diversification and the morphogenesis of different structures is achieved by generating precise patterns of HOX expression along the antero–posterior axis and by the ability of different HOX TFs to instruct unique and specific transcriptional programs. However, HOX binding properties in vitro, characterised by the recognition of similar AT-rich binding sequences, do not account for the ability of different HOX to instruct segment-specific transcriptional programs. To address this problem, we previously compared HOXA2 and HOXA3 binding in vivo. Here, we explore if sequence motif enrichments observed in vivo are explained by binding affinities in vitro. Unexpectedly, we found that the highest enriched motif in HOXA2 peaks was not recognised by HOXA2 in vitro, highlighting the importance of investigating HOX binding in its physiological context. We also report the ability of HOXA2 and HOXA3 to heterodimerise, which may have functional consequences for the HOX patterning function in vivo.


2019 ◽  
Vol 9 (4) ◽  
pp. 752 ◽  
Author(s):  
Junhua Gu ◽  
Chuanxin Lan ◽  
Wenbai Chen ◽  
Hu Han

While remarkable progress has been made to pedestrian detection in recent years, robust pedestrian detection in the wild e.g., under surveillance scenarios with occlusions, remains a challenging problem. In this paper, we present a novel approach for joint pedestrian and body part detection via semantic relationship learning under unconstrained scenarios. Specifically, we propose a Body Part Indexed Feature (BPIF) representation to encode the semantic relationship between individual body parts (i.e., head, head-shoulder, upper body, and whole body) and highlight per body part features, providing robustness against partial occlusions to the whole body. We also propose an Adaptive Joint Non-Maximum Suppression (AJ-NMS) to replace the original NMS algorithm widely used in object detection, leading to higher precision and recall for detecting overlapped pedestrians. Experimental results on the public-domain CUHK-SYSU Person Search Dataset show that the proposed approach outperforms the state-of-the-art methods for joint pedestrian and body part detection in the wild.


Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3518 ◽  
Author(s):  
Asmus Skar ◽  
Assaf Klar ◽  
Eyal Levenberg

The evaluation of soil reaction in geotechnical foundation systems such as concrete pavements, mat- and raft foundations is a challenging task, as the process involves both the selection of a representative mechanical model (e.g., Winkler, Continuum, Pasternak, etc.) and identify its prevailing parameters. Moreover, the support characteristics may change with time and environmental situation. This paper presents a new method for the characterization of plate foundation support using high-resolution fiber-optic distributed strain sensing. The approach involves tracking the location of distinct points of zero and maximum strains, and relating the shift in their location to the changes in soil reaction. The approach may allow the determination of the most suited mechanical model of soil representation as well as model parameters. Routine monitoring using this approach may help to asses the degradation of the subsoil with time as part of structural health monitoring strategies. In this paper, fundamental expressions that relate between the location of distinct strain points and the variation of soil parameters were developed based on various analytical foundation support models. Finally, as an initial validation step and to underpin the idea basics, the proposed method was successfully demonstrated on a simple mechanical setup. It is shown that the approach allows for load-independent characterization of the soil response and, in that sense, it is superior to common identification methods.


2016 ◽  
Vol 09 (02) ◽  
pp. 1650024 ◽  
Author(s):  
Bin Hu ◽  
Yaolu Liu ◽  
Ning Hu ◽  
Liangke Wu ◽  
Huiming Ning ◽  
...  

A strain sensor based on the composites of poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) filled by multi-walled carbon nanotube (MWNT) was prepared using a proposed fabrication process. Three kinds of MWNT loadings, i.e., 1.0[Formula: see text]wt.%, 2.0[Formula: see text]wt.% and 3.0[Formula: see text]wt.% were employed. Due to good dispersion state of MWNT in PVDF-HFP matrix, which was characterized by scanning electron microscope (SEM), this sensor was found to be of high sensitivity and stable performance. The sensor’s piezoresistivity varied in a weak nonlinear pattern, which was probably caused by the tunneling effect among neighboring MWNTs. The gauge factor of the sensor of 1.0[Formula: see text]wt.% MWNT loading was identified to be the highest, i.e., 33. This sensor gauge factor decreased gradually with the increase of addition amount of MWNT, which was 5 for the sensor of 3.0[Formula: see text]wt.% MWNT loading. This gauge factor was still higher than that of conventional metal-foil strain sensors. The electrical conductivity of PVDF-HFP/MWNT composites was also studied. It was found that with the increase of the addition amount of MWNT, the electrical conductivity of the PVDF-HFP/MWNT composites varied in a perfect percolation pattern with a very low percolation threshold, i.e., 0.77 vol.%, further indicating the very good dispersion of MWNT in the PVDF-HFP matrix.


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