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Åkerfeldt, Maria
Publications (9 of 9) Show all publications
Åkerfeldt, M. (2015). Electrically conductive textile coatings with PEDOT:PSS. (Doctoral dissertation). Borås: Högskolan i Borås
Open this publication in new window or tab >>Electrically conductive textile coatings with PEDOT:PSS
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In smart textiles, electrical conductivity is often required for several functions, especially contacting (electroding) and interconnecting. This thesis explores electrically conductive textile surfaces made by combining conventional textile coating methods with the intrinsically conductive polymer complex poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS).

PEDOT:PSS was used in textile coating formulations including polymer binder, ethylene glycol (EG) and rheology modifier. Shear viscometry was used to identify suitable viscosities of the formulations for each coating method. The coating methods were knife coating, pad coating and screen printing. The first part of the work studied the influence of composition of the coating formulation, the amount of coating and the film formation process on the surface resistivity and the surface appearance of knife-coated textiles. The electrical resistivity was largely affected by the amount of PEDOT:PSS in the coating and indicated percolation behaviour within the system. Addition of a high-boiling solvent, i.e. EG, decreased the surface resistivity with more than four orders of magnitude. Studies of tear strength and bending rigidity showed that textiles coated with formulations containing larger amounts of PEDOT:PSS and EG were softer, more ductile and stronger than those coated with formulations containing more binder. The coated textiles were found to be durable to abrasion and cyclic strain, as well as quite resilient to the harsh treatment of shear flexing. Washing increased the surface resistivity, but the samples remained conductive after five wash cycles.

The second part of the work focused on using the coatings to transfer the voltage signal from piezoelectric textile fibres; the coatings were first applied using pad coating as the outer electrode on a woven sensor and then as screen-printed interconnections in a sensing glove based on stretchy, warp-knitted fabric. Sensor data from the glove was successfully used as input to a microcontroller running a robot gripper. These applications showed the viability of the concept and that the coatings could be made very flexible and integrated into the textile garment without substantial loss of the textile characteristics. The industrial feasibility of the approach was also verified through the variations of coating methods.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2015. p. 46
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 56
Keywords
textile coating, conductive coating, conjugated polymers, ICP, PEDOT:PSS, textile properties, textile sensor, printed electronics, Smart textiles, poly(3, 4-ethylene dioxythiophene)-poly(styrene sulfonate)
National Category
Engineering and Technology
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-19 (URN)9789187525391 (ISBN)9789187525407 (ISBN)
Public defence
2015-03-23, T154, The Swedish School of Textiles, Skaraborgsvägen 3A, Borås, 13:00 (English)
Opponent
Available from: 2015-05-19 Created: 2015-02-16 Last updated: 2015-12-18Bibliographically approved
Åkerfeldt, M., Lund, A. & Walkenström, P. (2015). Textile sensing glove with piezoelectric PVDF fibers and printed electrodes of PEDOT:PSS. Textile research journal, 85(17), 1789-1799
Open this publication in new window or tab >>Textile sensing glove with piezoelectric PVDF fibers and printed electrodes of PEDOT:PSS
2015 (English)In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 85, no 17, p. 1789-1799Article in journal (Refereed) Published
Keywords
textile sensor, smart textile
National Category
Textile, Rubber and Polymeric Materials
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-4065 (URN)10.1177/0040517515578333 (DOI)000361487600003 ()2-s2.0-84941924200 (Scopus ID)
Available from: 2015-12-15 Created: 2015-12-15 Last updated: 2018-12-01Bibliographically approved
Åkerfeldt, M., Nilsson, E., Gillgard, P. & Walkenström, P. (2014). Textile piezoelectric sensors: melt spun bi-component poly(vinylidene fluoride) fibres with conductive cores and poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) coating as the outer electrode. Fashion and Textiles, 1(13)
Open this publication in new window or tab >>Textile piezoelectric sensors: melt spun bi-component poly(vinylidene fluoride) fibres with conductive cores and poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) coating as the outer electrode
2014 (English)In: Fashion and Textiles, ISSN 2198-0802, Vol. 1, no 13Article in journal (Refereed) Published
Abstract [en]

The work presented here addresses the outer electroding of a fully textile piezoelectric strain sensor, consisting of bi-component fibre yarns of β-crystalline poly(vinylidene fluoride) (PVDF) sheath and conductive high density polyethylene (HDPE)/carbon black (CB) core as insertions in a woven textile, with conductive poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) coatings developed for textile applications. Two coatings, one with a polyurethane binder and one without, were compared for the application and evaluated as electrode material in piezoelectric testing, as well as tested for surface resistivity, tear strength, abrasion resistance and shear flexing. Both coatings served their function as the outer electrodes in the system and no difference in this regard was detected between them. Omission of the binder resulted in a surface resistivity one order of magnitude less, of 12.3 Ω/square, but the surface resistivity of these samples increased more upon abrasion than the samples coated with binder. The tear strength of the textile coated with binder decreased with one third compared to the uncoated substrate, whereas the tear strength of the coated textile without binder increased with the same amount. Surface resistivity measurements and scanning electron microscopy (SEM) images of the samples subjected to shear flexing showed that the coatings without the binder did not withstand this treatment, and that the samples with the binder managed this to a greater extent. In summary, both of the PEDOT:PSS coatings could be used as outer electrodes of the piezoelectric fibres, but inclusion of binder was found necessary for the durability of the coating.

Place, publisher, year, edition, pages
SpringerOpen, 2014
Keywords
Textile technology
National Category
Other Materials Engineering Materials Engineering
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-1919 (URN)10.1186/s40691-014-0013-6 (DOI)2320/14287 (Local ID)2320/14287 (Archive number)2320/14287 (OAI)
Funder
VINNOVA
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-02Bibliographically approved
Åkerfeldt, M. (2014). Towards screen-printed electronics for smart textile applications with PEDOT:PSS. In: : . Paper presented at 14th AUTEX World Textile Conference, 26-28 May 2014, Bursa, Turkey.
Open this publication in new window or tab >>Towards screen-printed electronics for smart textile applications with PEDOT:PSS
2014 (English)Conference paper, Published paper (Refereed)
Keywords
Textile technology
National Category
Materials Engineering
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-7257 (URN)2320/14424 (Local ID)2320/14424 (Archive number)2320/14424 (OAI)
Conference
14th AUTEX World Textile Conference, 26-28 May 2014, Bursa, Turkey
Funder
VINNOVA
Note

Sponsorship:

Sparbanksstiftelsen Sjuhärad; Smart Textiles -VINNOVA

Available from: 2015-12-22 Created: 2015-12-22 Last updated: 2017-02-22Bibliographically approved
Åkerfeldt, M., Strååt, M. & Walkenström, P. (2013). Electrically conductive textile coating with a PEDOT-PSS dispersion and a polyurethane binder. Textile research journal, 83(6), 618-627
Open this publication in new window or tab >>Electrically conductive textile coating with a PEDOT-PSS dispersion and a polyurethane binder
2013 (English)In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 83, no 6, p. 618-627Article in journal (Refereed) Published
Abstract [en]

Electrically conductive textile coatings have been prepared by the addition of a dispersion of poly(3,4-ethylenedioxy thiophene)-polystyrene sulfonate (PEDOT-PSS) and ethylene glycol to a polyurethane-based coating formulation. The formulations were designed to have similar viscosities, measured with a rheometer using a cone-and-plate set-up. The formulations were applied to woven poly(ethylene) terephthalate substrates using a direct coating method. The concentration PEDOT-PSS in the finished coatings varied between 0.7 and 6.2 wt%, the coating deposit between 19 and 155 g/m2 and the drying procedure between 4 hours at 20 C and 10 minutes at 150 C. Surface resistivity was measured with a ring probe and surface topology was addressed with scanning electron microscopy (SEM). The PEDOT-PSS concentration had a large effect on the resistivity, which dropped by five orders of magnitude with an increased concentration. The steepest decrease occurred between 1 and 3 wt% PEDOT-PSS, indicating a percolation threshold. An increased coating deposit resulted in a resistivity drop by a factor 10, but no significant effect on the resistivity of the samples could be ascertained by variation of the drying conditions when samples had been subjected to subsequent annealing.

Place, publisher, year, edition, pages
Sage Publications, 2013
Keywords
Coatings, composites, incorporation, intrinsically conductive polymers, measurement, properties, Textile technology
National Category
Materials Engineering
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-1345 (URN)10.1177/0040517512444330 (DOI)000317934000006 ()2320/11564 (Local ID)2320/11564 (Archive number)2320/11564 (OAI)
Note

Sponsorship:

Sparbanksstiftelsen Sjuhärad; the Smart Textiles initiative

Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-02Bibliographically approved
Åkerfeldt, M., Strååt, M. & Walkenström, P. (2013). Influence of coating parameters on textile and electrical properties of a poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)/polyurethane-coated textile. Textile research journal, 83(20), 1-13
Open this publication in new window or tab >>Influence of coating parameters on textile and electrical properties of a poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)/polyurethane-coated textile
2013 (English)In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 83, no 20, p. 1-13Article in journal (Refereed) Published
Abstract [en]

Textile coatings with electrical conductivity were obtained by the addition of poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) and ethylene glycol (EG) to a polyurethane (PU)-based coating formulation. Variations of the coating formulation, the coating amount and the drying conditions, as well as the absence of an annealing step, were investigated. The coated fabrics were evaluated for tear strength and bending rigidity as well as surface resistivity and appearance before and after Martindale abrasion. A high proportion of PEDOT:PSS dispersion in the formulation and the presence of EG provided low surface resistivity. This composition resulted in softer samples with higher tear strength than those containing more PU-binder. All coatings proved to withstand abrasion to a similar extent. The surface resistivity increased gradually with the abrasion, about one half order of magnitude, except for those coatings that had been subjected to a faster drying process, where the surface resistivity increased somewhat faster.

Place, publisher, year, edition, pages
Sage Publications Ltd., 2013
Keywords
Textile technology, Smart Textiles
National Category
Materials Engineering
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-1625 (URN)10.1177/0040517513487786 (DOI)000327372700006 ()2320/12715 (Local ID)2320/12715 (Archive number)2320/12715 (OAI)
Note

Sponsorship:

Sparbanksstiftelsen Sjuhärad, Smart Textiles

Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-02Bibliographically approved
Åkerfeldt, M. (2013). The influence of ethylene glycol on the properties of electrically conductive textile coatings obtained with PEDOT:PSS. In: : . Paper presented at 13th AUTEX World Textile Conference 2013. AUTEX 2013 Proceedings
Open this publication in new window or tab >>The influence of ethylene glycol on the properties of electrically conductive textile coatings obtained with PEDOT:PSS
2013 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Ethylene glycol (EG) is known as a conductivity-enhancer of films made of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS), a degrading agent of polyethylene terephtalate (PET) and a plasticizer of latex. The influence of ethylene glycol (EG) on PET-textiles coated with polyurethane (PU) and PEDOT:PSS dispersions was therefore studied with respect to surface resistivity as a means to appreciate conductivity, and tear and tensile strength to appreciate the mechanical properties. Samples of the PET substrate were also immersed in a 20 w/w-% EG solution and Fourier transform infrared spectroscopy (FTIR) was used to detect any PET degradation. The resistivity dropped with three orders of magnitude with 10 % EG of PEDOT:PSS dispersion, i.e. 6 wt-% of the entire coating formulation. The addition of EG did not affect the tear and tensile strength of the coated samples, nor did subjection to EG-solution have a degrading effect on the PET substrate, indicating that EG does not deteriorate the coated textile.

Place, publisher, year, edition, pages
AUTEX 2013 Proceedings, 2013
Keywords
textile coating, intrinsically conductive polymers, PEDOT:PSS, ethylene glycol, secondary dopants, Textile technology, Smart Textiles
National Category
Materials Engineering
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-7026 (URN)2320/12716 (Local ID)978-3-86780-342-7 (ISBN)2320/12716 (Archive number)2320/12716 (OAI)
Conference
13th AUTEX World Textile Conference 2013
Note

Sponsorship:

The Smart Textiles initiative

Available from: 2015-12-22 Created: 2015-12-22 Last updated: 2017-10-24Bibliographically approved
Åkerfeldt, M. (2012). Studies of electrically conductive textile coatings with PEDOT:PSS. (Licentiate dissertation). Chalmers University of Technology
Open this publication in new window or tab >>Studies of electrically conductive textile coatings with PEDOT:PSS
2012 (English)Licentiate thesis, monograph (Other academic)
Abstract [en]

This study investigates electrically conductive coatings of textiles, obtained with a direct coating and the addition of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) dispersion to a thickened polyurethane (PU)-based formulation. Textiles with enhanced electrical conductivity have potential applications in antistatic, electrostatic discharge protective, electromagnetic interference shielding, sensoric and temperature-regulating products. The composition of the coating formulation will have a large impact on the obtained coated textiles. Firstly, the amount solids (polymer content) of the components will affect the shear viscosity which is amongst other important for the level of penetration of the coating. In this work, different coating formulations have been studied with steady state shear viscometry. It was found that the viscosity during knife coating to a large extent could be controlled by the addition of a hydrophobically modified ethoxylated urethane (HEUR) rheology modifier. Secondly, the level of conductivity will depend on the amount conductive material, in this case PEDOT:PSS, that is present in the coating, indicating percolation behaviour of the system. Conductivity was evaluated with two-point and four-point surface resistivity measurements. Addition of a high-boiling solvent, i.e. ethylene glycol, was however imperative for low surface resistivity. Thirdly, tear strength measurements, performed with the dynamic pendulum method, and investigations of bending rigidity, with the Kawabata evaluation system for fabrics, KES-F-2, showed that samples coated with formulations containing larger amounts of PEDOT:PSS and ethylene glycol were significantly softer and more ductile than samples coated with formulations containing more binder. A decrease in surface resistivity could also be obtained by increasing the amount deposited coating on the substrate. This decrease was however counteracted by the concurrent increase of insulating binder polymers in the coating. The increased coating deposit resulted in stiffer samples with lower tear strength due to increased brittleness. The influence of kinetics during film formation on the surface resistivity was also studied but was found to be close to insignificant. Abrasion resistance was investigated for all samples with a modified Martindale method and the samples showed less impact from this than expected.

Place, publisher, year, edition, pages
Chalmers University of Technology, 2012
Series
Technical report, ISSN 1652-8891 ; 78
Keywords
textile coating, conductive coating, conjugated polymers, coating parameters, PEDOT:PSS, Textile technology
National Category
Materials Engineering
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-3636 (URN)2320/11531 (Local ID)2320/11531 (Archive number)2320/11531 (OAI)
Note

Sponsorship:

Sparbanksstiftelsen Sjuhärad, Smart Textiles

Available from: 2015-12-04 Created: 2015-12-04
Åkerfeldt, M. & Strååt, M. (2011). A Rheological Study of a Textile Coating Paste containing PEDOT:PSS. In: : . Paper presented at Nordic Rheology Conference 2011, Helsinki. Nordic Rheology Society
Open this publication in new window or tab >>A Rheological Study of a Textile Coating Paste containing PEDOT:PSS
2011 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

A conductive coating paste suitable for knife coating of textiles can be obtained with PEDOT:PSS, a polyurethane based binder, ethylene glycol and a rheology modifier. The influence of each component, as well as combinatory effects, has been studied with shear viscometry. Indicated associative interactions between the components are discussed.

Place, publisher, year, edition, pages
Nordic Rheology Society, 2011
Keywords
conductive coatings, intrinsically conductive polymers, viscosity, PEDOT:PSS, Textile Technology
National Category
Engineering and Technology Textile, Rubber and Polymeric Materials
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-6757 (URN)2320/10260 (Local ID)2320/10260 (Archive number)2320/10260 (OAI)
Conference
Nordic Rheology Conference 2011, Helsinki
Funder
VINNOVA
Note

Prof. Pernilla Walkenström from Swerea IVF and Prof. Bengt Hagström, also from Swerea IVF, are thanked for their scientific guidance.

Available from: 2015-12-22 Created: 2015-12-22 Last updated: 2017-09-20Bibliographically approved
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