Development of a flex and stretchy conductive cotton fabric via flat screen printing of PEDOT : PSS/PDMS conductive polymer composite

In this work, we have successfully produced a conductive and stretchable knitted cotton fabric by screen printing of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and poly(dimethylsiloxane-b-ethylene oxide)(PDMS-b-PEO) conductive polymer composite. It was observed that the mechanical and electrical properties highly depend on the proportion of the polymers, which opens a new window to produce PEDOT:PSS-based conductive fabric with distinctive properties for different application areas. The bending length analysis proved that the flexural rigidity was lower with higher PDMS-b-PEO to PEDOT:PSS ratio while tensile strength was increased. The SEM test showed that the smoothness of the fabric was better when PDMS-b-PEO is added compared to PEDOT:PSS alone. Fabrics with electrical resistance from 24.8 to 90.8 k ohm/sq have been obtained by varying the PDMS-b-PEO to PEDOT:PSS ratio. Moreover, the resistance increased with extension and washing. However, the change in surface resistance drops linearly at higher PDMS-b-PEO to PEDOT:PSS ratio. The conductive fabrics were used to construct textile-based strain, moisture and biopotential sensors depending upon their respective surface resistance

PEDOT:PSS/PDMS-coated cotton fabric for strain and moisture sensors

In this work, we have successfully developed a flexible, lightweight, and washable strain and moisture sensor textile fabric by printing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/polydimethylsiloxane-b-polyethylene oxide (PEDOT:PSS/PDMS) conductive polymer composite on knitted cotton fabric. A 60.2 kΩ/sq surface resistance has been obtained at a 30% ratio of PDMS to PEDOT:PSS at 0.012 g/cm2 solid add-on. The coated fabric was washed at 30 °C for 30 min in the presence of a standard detergent. It was observed that there was a 5.3% increase in surface resistance, i.e., 63.4 kΩ/sq. After coating, the fabric could still be stretched up to the infliction elongation of the fabric, i.e., 40%, with a significant change in surface resistance that makes it usable as a strain sensor. In addition, the conductive fabric showed a drop in surface resistance with an increase of the moisture regain up to 150%

Textile Printing: Design and Process

Richard Malachowski has an eclectic background in textiles with decades of experience as a textile chemist and director of research and engineering at Cranston Print Works. Using that experience, he described how a textile print is created from design concept through production. Showing physical textile samples, he explained the process of rotary screen printing, flat bed screen printing, and ink jet printing

Textiles screen-printed with photochromic ethyl cellulose-spirooxazine composite nanoparticles

Photochromic compounds change colour on exposure to light, while the reversion may be attributable either to radiation or may be thermal. The use of photochromism on fabrics can provide new opportunities to develop smart textiles; for example, sensors and active protective clothes. Ethyl cellulose-1,3-dihydro-1,3,3,4,5 (and 1,3,3,5,6) -pentamethyl-spiro-[2H-indole-2,3′-(3H)naphtha(2,1-b)(1,4)oxazine] composites were prepared by an oil-in-water emulsion, solvent evaporation method in order to form easily suspendable and fatigue-resistant photochromic nanoparticles in screen-printing paste. Their size was well below 1 μm and did not change substantially over a wide range of dye concentrations. After screen-printing, a homogenous photochromic layer was built on a cotton substrate surface, which represented substantial blue colour development in CIELab colour space measurements because of ultraviolet light, even at a dye concentration of 0.045% w/w. The addition of a photodegradation inhibitor, Tinuvin 144, further increased the coloration of the printed fabric

A washable silver-printed textile electrode for ECG monitoring

Electrocardiography (ECG) is one of the most widely used diagnostic methods to examine the development of cardiovascular diseases (CVD). It is important to have a long-term continuous ECG recording to properly monitor the heart activity, which can be measured by placing two or more electrodes on the skin. Ag/AgCl gelled electrodes are often used for the ECG measurement, but they are not suitable for long-term monitoring due to the dehydration of the gel over time and skin irritation. Textile-based electrodes could have an important role in replacing the gelled electrodes and avoid their associated problems. This paper focuses on the development of a textile-based electrode and studying its ECG detecting performance. We developed silver printed textile electrodes via a flat-screen printing of silver ink on knitted polyester fabric. The surface resistance of silver-coated PET fabric was 1.78 Ω/sq and 3.77 Ω/sq before and after washing, respectively. Stretching of the conductive fabric from 5% to 40% caused a 6% to 18.28% increase in surface resistance. The silver-printed PET fabric stayed reasonably conductive after washing and stretching which makes it suitable for wearable applications. Moreover, the ECG measurement at static condition showed that the signal quality collected before and after washing were comparable with the Ag/AgCl standard electrodes. The P, QRS, T waveforms, and heartbeat before washing in respective order were 0.09 mV, 1.20 mV, 0.30 mV for the silver printed fabric electrode and 72 bpm, and 0.10 mV, 1.21 mV, 0.30 mV, and 76 bpm for Ag/AgCl standard electrode

Pembuatan Karboksimetil Selulosa Dari Limbah Tongkol Jagung Untuk Pengental Pada Proses Pencapan Tekstil

Limbah pertanian, antara lain tongkol jagung sampai saat ini belum dimanfaatkan secara optimal. Untukitu dilakukan penelitian dengan tujuan menaikkan nilai tambah limbah tersebut melalui proses karboksimetilasi,sehingga dihasilkan produk, yaitu karboksimetil selulosa (CMC) yang dapat digunakan sebagai pengental padaproses pencapan tekstil. Penelitian dilakukan melalui beberapa tahapan proses, meliputi pemurnian awal,delignifikasi, alkalisasi, karboksimetilasi, pemurnian CMC, penetralan dan pengeringan. Reaksi karboksimetilasiyang terjadi dapat diketahui melalui analisa dengan spektra FTIR yang menunjukkan adanya gugus fungsi C=O.Percobaan dilakukan dengan 4 (empat) variasi proses, dan kondisi optimal dicapai pada Variasi Proses IV,yaitu proses tanpa pemurnian awal dan delignifikasi yang menghasilkan derajat substitusi (DS) 0,55. Pada prosespencapan kain kapas dengan zat warna reaktif menggunakan kasa datar, digunakan CMC tongkol jagung tersebutdengan viskositas 1750 cps. Untuk mencapai viskositas tersebut diperlukan CMC 16,5%, sedangkanpembandingnya (CMC komersil) hanya 2,1%. Namun demikian memberikan kualitas pencapan yang cukup baik,yaitu tidak memberikan efek migrasi dan ketuaan warnanya terhadap CMC komersil relatif sama (rata - rata Δ E <1). Selain itu tahan luntur warnanya terhadap pencucian, gosokan, keringat dan sinar menunjukkan nilai baik dankekakuan kainnya relatif sama dengan kain tanpa cap. Dengan demikian CMC hasil penelitian ini memenuhipersyaratan sebagai pengental untuk proses pencapan tersebut, karena tidak menodai kain putih, tidak berpengaruhterhadap warna dari zat warna yang digunakan dan mudah dihilangan pada proses pencucian

PEDOT : PSS-based conductive textiles and their applications

The conductive polymer complex poly (3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most explored conductive polymer for conductive textiles applications. Since PEDOT:PSS is readily available in water dispersion form, it is convenient for roll-to-roll processing which is compatible with the current textile processing applications. In this work, we have made a comprehensive review on the PEDOT:PSS-based conductive textiles, methods of application onto textiles and their applications. The conductivity of PEDOT:PSS can be enhanced by several orders of magnitude using processing agents. However, neat PEDOT:PSS lacks flexibility and strechability for wearable electronics applications. One way to improve the mechanical flexibility of conductive polymers is making a composite with commodity polymers such as polyurethane which have high flexibility and stretchability. The conductive polymer composites also increase attachment of the conductive polymer to the textile, thereby increasing durability to washing and mechanical actions. Pure PEDOT:PSS conductive fibers have been produced by solution spinning or electrospinning methods. Application of PEDOT:PSS can be carried out by polymerization of the monomer on the fabric, coating/dyeing and printing methods. PEDOT:PSS-based conductive textiles have been used for the development of sensors, actuators, antenna, interconnections, energy harvesting, and storage devices. In this review, the application methods of PEDOT:SS-based conductive polymers in/on to a textile substrate structure and their application thereof are discussed

Factor affecting absorbency behaviour of woven velour printed terry fabrics

The present research work is aimed at designing the woven velour printed terry fabrics with improved overall performance. The influence of pile height, pick density and pile count (one ply and two ply both) on the water absorbency of fabric has been studied. Thirty samples have been prepared by changing variables as per Box – Behnken design of experiments. These variables are optimised for achieving high quality woven velour printed terry fabrics. The findings show that the absorbency of these fabrics increases with the increase in pile height and pick density. The results are found true for both the fabrics having one ply and two ply pile yarns. The absorbency of the fabrics having two ply pile yarn is always higher as compared to fabric having one ply pile yarn. The absorbency behaviour of these fabrics is different from the looped woven terry fabric which clearly indicates the importance of loop geometry

Effect of chitosan on resist printing of cotton fabrics with reactive dyes

The concentration of chitosan, types of resist agent, curing temperature and curing time were varied to determine their effects on resist-printed cotton fabrics. An optimal chitosan concentration of 1.6% resulted in the greatest resist effect on printed cotton fabrics. For mixtures, a 6:4 ratio of citric acid : chitosan and an 8:2 mixture of tartaric acid : chitosan yielded the greatest resist effects. A curing temperature of 150°C for 180 s was optimal.Key words: Chitosan, resist printing, reactive dyes, cotton fabrics