E-textile: A New Sensation in Textiles

National Institute of Textile Engineering and Research (NITER), one of the leading academic and research institutes of the country is working on different research projects in order to promote technological innovation in the textile industry. Recently a talented team has been working on developing diversified E-textile products as a part of its research activities. They have already demonstrated their products at the last 17th TEXTECH Bangladesh International Expo 2016 held in last September and acquired much appreciation from the visitors. They are trying to develop their products to the next level. Here they have shared the overview of their research work and the prospects of E-textile.

Jahid Sarker^a, A.K.M. Monjurul Haque^a, Md. Abdullah al Rumon^b, Md. Masudur Rahman^b

^a Lecturer, National Institute of Textile Engineering and Research (NITER)

^b 3^rd Year Student of National Institute of Textile Engineering and Research (NITER)

Abstract

In general view, E-Textile or Electronic textile means a type of composite product in where textile material (like fibre, yarn, fabric, garments etc.) embedded with electrical equipment. In general, the development of electronic textiles not only supports the idea of wearable properties but also do the functional purposes. Within the relatively new industry around electronic textiles, projects are pursued based on various different kinds of functionality. All over the world many institute and company are doing many research because of its upcoming large market. The market value estimates for smart fabrics range from US$1.6 bn and US$2.9 bn by 2020 and IDTechEx forecasts that the market will reach over $3bn by 2026.So Bangladesh has a high probability to grab this market through researching and using new technology.

Introduction

Electronic Textiles (e-textiles) are fabrics that feature electronics and interconnections woven into them, presenting physical flexibility and typical size that cannot be achieved with other existing electronic manufacturing techniques. E-textiles, refers to fabrics that can function electrically as electronics and behave physically as textiles Electronic-textile research is closely related to wearable computing research, but in many ways its own distinct field. Wearable computing explores technologies that are portable and attached to or carried on the body, but e-textile research has a slightly different focus: investigating electronic and computational technology that is imbedded into textiles. E-textile researchers strive to build devices that are as soft, flexible and comfortable as traditional cloth artifacts.

Using Sensors provide a nervous system to detect signals, thus in a passive smart material, the existence of sensors is essential and wireless option gives the ultimate availability to measure information or to send data instantly. All over the world there is a large field to work with and characterizes key market sectors including ‘Sports & Fitness’, ‘Medical & Healthcare’, ‘Wellness’, ‘Home & Lifestyle’, ‘Industrial, commercial, military’, ‘Fashion’ and ‘Others’ (including automotive) giving more opportunities.

Converting General textile to e-textile.

There are many way to convert ordinary garment to electrically modified garment. We can do that by

• Making conductive thread/yarn
• Making conductive fabric
• Using conductive ink
• Using optical fiber
• Adding electronic product severally with associate tools
• Adding sensors to get real time data

1. Conductive yarn\thread

From the electrical points of view, conductivity is the most important factor. Electrical resistance need to be low enough to allow a flow of electric energy, such as for power or data transmission, is critical. Metal, carbon, or optical fibers are typically well-known conductors. Advanced technologies are required to produce process able fibers and yarns out of these materials. From the textile point of view, e-textiles need to be designed to exhibit physical properties similar to those of traditional textiles. E-textiles should be bendable, stretchable, and washable while keeping good electrical conductivity.

The Swiss company Elektrisola Feindraht AG (Escholzmatt, Switzerland) produces metal monofilaments that can be blended with all sorts of fibers or that can be directly used in weaving and knitting. Below chart shows conductivity, resistance and TCR of different metal.

There are few structural way to make a yarn conductive. The structures of conductive yarn could be categorized into three classes:

• Metal-wrapped yarn is a composite of metal and yarn. A conductive yarn mainly consists of a strand of non-conductive yarn wrapped with one or more metal wires (a)
• For metal-filled yarns, a fine metal wire serves as a core covered by non-conductive fibers. (b)

• Metal yarn does not take a core-sheath structure. Metal fibers that are very finely drawn
  replace one strand or entire strands of the yarn. (c)

1. Metal-wrapped yarn manufacturing process

There are a lot of Process of coating and twisting procedure. In general coating and twisting application is done as the way following figure shows.

Instead of attaching electronics to textile substrates, the yarns of the textile can be fictionalized with electronics. Electrically conductive fibers can also be produced by coating the fibers with metals, galvanic substances or metallic salts. Coatings can be applied to the surface of fibers, yarns, or even fabrics to create electrically conductive textiles. Another relevant work is to use the crossing yarns in a textile to

fabricate a transistor [44, 45]. A schematic of a yarn-based transistor is shown in figure. The resulting transistor shows an on-off current ratio of more than 1000, operated with a gate voltage of 1.5 V.

2. Conductive Fabric

A conductive textile is a fabric which can conduct electricity.

Here are different ways to produce electrically conductive fabrics. One method is by using conductive yarns in a textile structure. However, the integration of conductive yarns in a structure is a complex as it needs to be ensured that the electrically conductive fabric is comfortable to wear or soft in touch rather than hard and rigid.

However, woven fabric structures can provide a complex network that can be used as elaborated electrical circuits with sensors and wireless encoder decoder and so on. Knitted fabric can be made conductive by using different yarn possible to make conductive yarn fully invisible.

For inkjet printing, the inks should respect the following requirements.

• high electrical conductivity;
• resistance to oxidation;
• dry out without clogging the nozzle during printing;
• good adhesion to the substrate;
• lower particle aggregation;
• suitable viscosity and surface tension

General properties of electrical ink given below:

Making E textile using a pad

It is the another way to make smart textile adding sensors, wireless circuit, LED etc. these parts come with extra features like heart bit sensor, temperature sensor , walking calculating sensor ,and wireless computing through Wi-Fi, Bluetooth, internet ,and SMD LED for display etc. Recently E-Textile based electronic shop started their business making their moto “Plug & Play”. KeKePad is a new generation of wearable and e-Textile platform, it uses super thin & flexible Ke cables to replace conductive thread. Ke cable is the thinnest 3-pin thread-like cable in the world. This pad can be used in any parts of garments like button, zipper, box plate, button plate etc. Actually depens on what will be the end uses suppose(i) if we want to get heart bits or blood circulation rate than it will attached in the zipper or box plate of a shirt to get the result (ii) if we want to get walking calculation than it will be attached in socks (iii)if we want to know body temperature than it will be attached anywhere of garments.

Our different potential Project Work

E-Textile is frontier of textile technology. We tried some research work on electronic textile. I got a big opportunity for upcoming year as now we live in the outskirts point of technology. I started with very beginning like the way electricity may pass across or along through the yarn and fabric. Then subsequent projects were very interesting where I used some logic gate and LED, and after then tried something complex. Here narrating one by one.

A) Lighted Fabric
Here very simple design is made by soldering LED light with conductive thread that I got from Headphones umbilical chord. It is flexible, bendable, washable and very lucent.

A) Lighted fabric using logic gate

B) Lighted fabric using Logic gate

It is little bit advance work controlling LED light through Logic gate. Here because of using logic gate LEDs are blinking simultaneously according to certain time lap. Lights are engaged by soldering with thread and gates are also added through the same way. Leds are sorted as like arrow. It is done on woven fabric, as it shows low sensibility and conserve thread from breaking down.

B) Lighted fabric using logic gate

C) Optical Fabric

Optical fiber is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber. Here I used plastic optical fiber in woven fabric as warp and it showed astonishing result. After warping all warp yarn be saved in a point and a light source was added there. Different light source color gives instant different color of that fabric.  This experiment allows probability of diverse field to use it.

D) E-Hat

It is very advance project. I worked with some very practical prospective area. We use hat / cap for saving us from direct sunlight. And nowadays all most every people carry mobile and other gadgets where charging is a big factor. For long time journey people use to listen Radio or Music where always keeping headphone is a disturbance. then if u go for a trip in outside then at night time you will feel the importance of light. All together Electric hat comes with all the solution.

Making a E- hat very easily this following way

• Fabric Selection
• Markering + Cutting
• Designed circuit sewing through conductive thread
• General components + Sensor embedding
• Covering with Non-oven for security
• Final garment sewing
• Adjoining microcontroller + battery pack
• Finishing

E) Fitness Tracking Tools

It is a very small and functional tool where it can be integrated with any Textile especially with Sports wear. The device can measure walking/running step as well as total amount of calory burning through this exercise. It is fully wireless and through android/iPhone data can be transmitted and seen very easily.

E) Fitness Tracking

We can a fitness tracking tools buy this way

• Fabric Selection
• Markering + Cutting
• Designed circuit sewing through conductive thread
• General components + Sensor embedding
• Covering with Non-oven for security
• Final garment sewing
• Adjoining micro controller + battery pack
• Finishing

F) Backpack for CYCLIST

It is my last work on electronic textile. Here I tried to develop something for a certain group of people. An International report says that, all over the world around 75% bicycle accidents occurs due to “BLIND TURN”. Where it means bicycle accident occurs because when a cycle turn to left or right, behind vehicle do not get any clear grasp so due to speed cycle gets fired. From this conception this Backpack is made. Here I have used Radio controlled data transfer system where Encoder is settled with the handle and Decoder is integrated with the Backpack along with SMD LED, Tiny microcontroller, electric thread, knitted, woven and non-woven fabric are used.

F) Different picture of backpack