Optical Humidity Sensor Based on Tapered Fiber with Multi-walled Carbon Nanotubes Slurry

Author(s):  
Habibah Mohamed ◽  
Ninik Irawati ◽  
Fauzan Ahmad ◽  
Mohd Haniff Ibrahim ◽  
Sumiaty Ambran ◽  
...  

<p>We demonstrated performance comparison of optical humidity sensor for bare and Multi-walled carbon nanotubes (MWCNTs) slurry coated tapered optical fiber. The starting material for MWCNTs slurry is MWCNTs- acrylonitrile butadiene styrene (ABS) based fused deposition modeling (FDM) 3D printer filament. The ABS was dissolved using acetone to produce MWCNTs-acetone suspension. The MWCNTs-acetone suspension was drop-casted on the tapered fiber to produce MWCNTs slurry by evaporation process at room temperature, which resulted the MWCNTs slurry attach to the tapered fiber. The MWCNTs slurry acts as the cladding for humidity changes measurement. The experimental works showed improvement of sensitivity from 3.811 μW/% of bare tapered fiber to 5.17 μW/% for the coated tapered fiber with MWCNTs slurry when the humidity varied from 45% to 80%.</p>

2021 ◽  
Vol 11 (19) ◽  
pp. 8798
Author(s):  
Thai-Hung Le ◽  
Van-Son Le ◽  
Quoc-Khanh Dang ◽  
Minh-Thuyet Nguyen ◽  
Trung-Kien Le ◽  
...  

This paper reports the synthesis of a new printable ABS–MWCNT composite filament, for use in fused deposition modeling (FDM), using an extrusion technique. Acrylonitrile butadiene styrene (ABS) and multi-walled carbon nanotubes (MWCNTs) were the initial materials used for fabricating the filaments. The MWCNTs were dispersed in ABS resin, then extruded through a single-shaft extruder in filament form, with MWCNT contents of 0.5%, 1%, 1.5%, 2%, 3% or 4% by weight. After extrusion, the diameter of the filaments was about 1.75 mm, making them appropriate for FDM. The as-synthesized filaments were then used in FDM to print out samples, on which tensile tests and other analyses were carried out. The results demonstrate that the sample with 2% MWCNTs had the highest strength value, 44.57 MPa, comprising a 42% increase over that of the pure ABS sample. The morphology and dispersion of MWCNTs in the composite were observed by field emission scanning electron microscopy (FESEM), demonstrating the uniform distribution of MWCNTs in the ABS matrix. The thermal behavior results indicated no significant change in the ABS structure; however, the melt flow index of the filaments decreased with an increase in the MWCNT content.


2018 ◽  
Vol 9 (1) ◽  
pp. 37 ◽  
Author(s):  
Luiz Ecco ◽  
Sithiprumnea Dul ◽  
Débora Schmitz ◽  
Guilherme Barra ◽  
Bluma Soares ◽  
...  

Acrylonitrile–butadiene–styrene (ABS) filled with 6 wt.% of multi-walled carbon nanotubes and graphene nanoplatelets was extruded in filaments and additively manufactured via fused deposition modeling (FDM). The electrical conductivity and electromagnetic interference shielding efficiency (EMI SE) in the frequency range between 8.2 and 12.4 GHz of the resulting 3D samples were assessed. For comparison purposes, compression molded samples of the same composition were investigated. Electrical conductivity of about 10−4 S·cm−1 and attenuations of the incident EM wave near 99.9% were achieved for the 3D components loaded with multi-walled carbon nanotubes, almost similar to the correspondent compression molded samples. Transmission electron microscopy (TEM) images of ABS composite filaments show that graphene nanoplatelets were oriented along the polymer flow whereas multi-walled carbon nanotubes were randomly distributed after the extrusion process. The electrical conductivity and electromagnetic interference (EMI) shielding properties of compression molded and FDM manufactured samples were compared and discussed in terms of type of fillers and processing parameters adopted in the FDM process, such as building directions and printing patterns. In view of the experimental findings, the role of the FDM processing parameters were found to play a major role in the development of components with enhanced EMI shielding efficiency.


2017 ◽  
Vol 898 ◽  
pp. 2384-2391
Author(s):  
Jin Zhu ◽  
Biao Wang

Multi-walled carbon nanotubes (MWCNTs)/acrylonitrile butadiene styrene (ABS) nanocomposites were prepared by melt blending and then filaments were obtained by melt extrusion method. The Scanning electron microscope (SEM) exhibited good dispersion of MWCNTs in the SAN phase of the ABS matrix. The rheological results showed that incorporation of MWCNTs into ABS resulted in higher storage modulus (G′) and loss modulus (G′′) than those of ABS, especially at low frequencies. The tensile strength and modulus of MWCNT/ABS nanocomposite filaments substantially increased with the MWCNTs content while the elongation at break decreased. Additionally, the addition of MWCNTs decreased the coefficient of linear thermal expansion. This study provides a basis for further development of MWCNT/ABS nanocomposites used for FDM process with desirable mechanical properties and good dimension stability.


2021 ◽  
Vol 11 (3) ◽  
pp. 1272
Author(s):  
Bartłomiej Podsiadły ◽  
Piotr Matuszewski ◽  
Andrzej Skalski ◽  
Marcin Słoma

In this publication, we describe the process of fabrication and the analysis of the properties of nanocomposite filaments based on carbon nanotubes and acrylonitrile butadiene styrene (ABS) polymer for fused deposition modeling (FDM) additive manufacturing. Polymer granulate was mixed and extruded with a filling fraction of 0.99, 1.96, 4.76, 9.09 wt.% of CNTs (carbon nanotubes) to fabricate composite filaments with a diameter of 1.75 mm. Detailed mechanical and electrical investigations of printed test samples were performed. The results demonstrate that CNT content has a significant influence on mechanical properties and electrical conductivity of printed samples. Printed samples obtained from high CNT content composites exhibited an improvement in the tensile strength by 12.6%. Measurements of nanocomposites’ electrical properties exhibited non-linear relation between the supply voltage and measured sample resistivity. This effect can be attributed to the semiconductor nature of the CNT functional phase and the occurrence of a tunnelling effect in percolation network. Detailed I–V characteristics related to the amount of CNTs in the composite and the supply voltage influence are also presented. At a constant voltage value, the average resistivity of the printed elements is 2.5 Ωm for 4.76 wt.% CNT and 0.15 Ωm for 9.09 wt.% CNT, respectively. These results demonstrate that ABS/CNT composites are a promising functional material for FDM additive fabrication of structural elements, but also structural electronics and sensors.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1589 ◽  
Author(s):  
Rui Guo ◽  
Zechun Ren ◽  
Xin Jia ◽  
Hongjie Bi ◽  
Haiying Yang ◽  
...  

This study was aimed at improving the conductivity of polylactic acid (PLA)-based composites by incorporating carbonaceous fillers. The composites with the addition of graphene nanoplatelets (rGO) or multi-walled carbon nanotubes (MWCNTs) were fabricated by the masterbatch melting method in order to improve the dispersion of the two kinds of nano-fillers. The results showed that, with the addition of 9 wt % rGO, the volume electrical resistivity of the composite reached the minimum electrical resistance of 103 Ω·m, at which point the conductive network in the composites was completely formed. The interfacial compatibility, apparent viscosity, and the thermal stability of the composite were also good. The rGO functionalized by sodium dodecylbenzene sulfonate (SDBS) was an efficient method to further improve the electrical conductivity of the composite, compared with tannic acid and MWCNTs. The resistivity was reduced by an order in magnitude. Patterns printed onto different baseplates by fused deposition modeling illustrated that the functionalized composite had certain flexibility and it is suitable for printing complex shapes.


Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 549 ◽  
Author(s):  
Rui Guo ◽  
Zechun Ren ◽  
Hongjie Bi ◽  
Min Xu ◽  
Liping Cai

The aim of the study was to improve the electrical and thermal conductivity of the polylactic acid/wood flour/thermoplastic polyurethane composites by Fused Deposition Modeling (FDM). The results showed that, when the addition amount of nano-graphite reached 25 pbw, the volume resistivity of the composites decreased to 108 Ω·m, which was a significant reduction, indicating that the conductive network was already formed. It also had good thermal conductivity, mechanical properties, and thermal stability. The adding of the redox graphene (rGO) combined with graphite into the composites, compared to the tannic acid-functionalized graphite or the multi-walled carbon nanotubes, can be an effective method to improve the performance of the biocomposites, because the resistivity reduced by one order magnitude and the thermal conductivity increased by 25.71%. Models printed by FDM illustrated that the composite filaments have a certain flexibility and can be printed onto paper or flexible baseplates.


2021 ◽  
Vol 896 ◽  
pp. 29-37
Author(s):  
Ján Milde ◽  
František Jurina ◽  
Jozef Peterka ◽  
Patrik Dobrovszký ◽  
Jakub Hrbál ◽  
...  

The article focused on the influence of part orientation on the surface roughness of cuboid parts during the process of fabricating by FDM technology. The components, in this case, is simple cuboid part with the dimensions 15 mm x 15mm x 30 mm. A geometrical model is defined that considers the shape of the material filaments after deposition, to define a theoretical roughness profile, for a certain print orientation angle. Five different print orientations in the X-axis of the cuboid part were set: 0°, 30°, 45°, 60°, and 90°. According to previous research in the field of FDM technology by the author, the internal structure (infill) was set at the value of 70%. The method of 3D printing was the Fused Deposition Modeling (FDM) and the material used in this research was thermoplastic ABS (Acrylonitrile butadiene styrene). For each setting, there were five specimens (twenty five prints in total). Prints were fabricated on a Zortrax M200 3D printer. After the 3D printing, the surface “A” was investigated by portable surface roughness tester Mitutoyo SJ-210. Surface roughness in the article is shown in the form of graphs (Fig.7). Results show increase in part roughness with increasing degree of part orientation. When the direction of applied layers on the measured surface was horizontal, significant improvement in surface roughness was observed. Findings in this paper can be taken into consideration when designing parts, as they can contribute in achieving lower surface roughness values.


Author(s):  
Meng Zhang ◽  
Xiaoxu Song ◽  
Weston Grove ◽  
Emmett Hull ◽  
Z. J. Pei ◽  
...  

Additive manufacturing (AM) is a class of manufacturing processes where material is deposited in a layer-by-layer fashion to fabricate a three-dimensional part directly from a computer-aided design model. With a current market share of 44%, thermoplastic-based additive manufacturing such as fused deposition modeling (FDM) is a prevailing technology. A key challenge for AM parts (especially for parts made by FDM) in engineering applications is the weak inter-layer adhesion. The lack of bonding between filaments usually results in delamination and mechanical failure. To address this challenge, this study embedded carbon nanotubes into acrylonitrile butadiene styrene (ABS) thermoplastics via a filament extrusion process. The vigorous response of carbon nanotubes to microwave irradiation, leading to the release of a large amount of heat, is used to melt the ABS thermoplastic matrix adjacent to carbon nanotubes within a very short time period. This treatment is found to enhance the inter-layer adhesion without bulk heating to deform the 3D printed parts. Tensile and flexural tests were performed to evaluation the effects of microwave irradiation on mechanical properties of the specimens made by FDM. Scanning electron microscopic (SEM) images were taken to characterize the fracture surfaces of tensile test specimens. The actual carbon nanotube contents in the filaments were measured by conducting thermogravimetric analysis (TGA). The effects of microwave irradiation on the electrical resistivity of the filament were also reported.


Sign in / Sign up

Export Citation Format

Share Document