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University of MauritiusFaculty of Engineering

Department of Textile Technology Postgraduate Research Degree

(MPhil/PhD)

Embedding Light and Sound in Textiles for Novel Effects in Interior Design

  Proposed by 

G.K.Bahadur

February 2010

IntroductionTextile materials such as woven, non-woven and knitted fabrics

are an excellent medium that can be used to integrate and accommodate

unobtrusive electronic devices.

For the first part of the research, much emphasis was placed on

the following:

• Finding different ways of embedding electronic wires and microelectronics into textile fabrics in a discreet manner.

• Applying available conductivity threads and printing pastes on fabrics without compromising its soft look and feel.

• Creating conductive printing paste that can be used on fabric.

• Developing innovative products such as the soft switch, E-Label and the E-print for commercialised garments.

• Carry out fabric tests such as burn, colourfastness and washing tests with the results recorded, analysed and compared. 2

2.1 Literature Review2.1.1 Related works

Research was carried out to find out the various products that have been

developed and commercialised over the past years. The ways these

products were constructed and integrated into textiles were also

recorded.

2.1.2 Commercial e-garments

Research was carried out to find out the various products that had been

developed and commercialised over the past years. Indeed many projects

had been undertaken to combine electronics with textile and nowadays

many fashion companies have commercialised electronic garments

which can be purchased at a reasonable price.

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2.1.3 Connecting Methods

In textile different ways to connect an electronic piece should be

considered. Clipping, stapling, gluing and snapping by using metal press

buttons were some methods that had been exploited in this project.

2.1.4 Power sources 

The different power sources available had to be considered since

electronic textiles need some kind of electrical power to work. Several

types of portable power sources exist which vary in size and power. 

2.1.5 Conductive Materials 

One very important aspect to consider was conductive materials that

could easily be incorporated discretely in textiles. Some of these

materials were also used in realising some experimental works in this

project.   4

2.1.6 Conductive Accessories in garments

Metal Accessories have been used in garments for many centuries.

They come in different forms and shapes and some are used for

specific functions whereas others are used for decorative purposes.

Most of the metals used, such as copper, aluminium and alloy, are

highly conductive.

2.1.7 LEDs

The definition of LED and the connection methods (parallel and in

series) were studied.

2.1.8 Resistors

The definition, function and the formula for determining the type of

resistor to use was considered.

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3.0 Methodology 3.1 Materials

Materials with good conductive properties, lightweight and thin were

sourced and different experiments were carried out. A preliminary

research was conducted and the main objective was to turn the

conductive materials into a printing paste in a very discrete manner

without compromising the drape and other properties of the fabric.

Different printing pastes were used and various tests were carried out.

Pastes such as expanding binder, high-density clear (H.D.C), normal

Binder and conductive printing paste were used.

 

3.1.1 Aluminium foil

Aluminium foil traditionally used in kitchen was used to carry

out the first set of experiments.6

3.1.2 Expanding Binder  

Expanding Binder is a printing paste and when heat is applied, the

print expands, giving a 3DM effect. 

3.1.3 High Density Clear (H.D.C)  

High Density clear is another commercial paste, which is thick,

opaque and sticky. When heated at very high temperature, it turns into

flexible silicone like material.

3.1.4 Silicone Glue

Silicones are largely inert, man-made compounds with a wide variety

of forms and uses. Typically heat-resistant, nonstick, and rubberlike,

they are commonly used in cookware, medical applications, sealants,

adhesives, lubricants, and insulation.

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3.1.5 Latex

Latex is a material that is used in many types of garments and is

commonly seen in fetish fashion and costume designs (in movies).

They are made in polymers and rubbers and their applications are

endless. Latex comes in large sheet and in liquid form. The large sheet

can be cut in any garment shapes and glued together to make garments.

The liquid latex can be applied to any surface. It will permanently bond

to porous materials such as fabric and non porous materials can be used

as a mould. The liquid latex contains ammonia as a preservative agent.

It will cure at room temperature but is prone to adhere to itself which

can be solved by treating the surface.

3.1.6 Conductive Tape/ Fabrics: Electronylon Nickel

This versatile fabric is composed of a woven substrate of high quality

polyester taffeta fabric with a copper and nickel plating giving great 8

conductivity. The production process is computer controlled to

Ensure consistency and the nickel gives the fabric a dull silver

appearance. It has exceptional electrical conductivity of 0 Ohms per

100 mm measured on a 25 mm wide strip (Data sheet available

from the Electrotextile Sample Pack, teaching resources, Middlesex

University).

3.1.7 Conductive Threads

This thread is sufficiently conductive and stronger as compared to

domestic poly/cotton thread and behaves like conventional cotton

and is made of over 100 strands each with nano-coating of silver. It

has an electrical resistance of just 4 Ohms per 100 mm.

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3.2 Experimental works

3.2.1 Expanding Binder and High Density Clear Paste (H.D.C.)

Target Set: Integrate LEDs in textile through prints.

Details: Expanding binder was used as a support to hold the LEDs

and the H.D.C was applied on the reverse side over the circuit as an

insulator. The circuit consisted of 5 LEDs and a resistor.

Target Achieved: Sample was connected to the power supply and lit

instantly. The integration of LEDs on the fabric surface was

successful although the fabric became a bit stiff because of the layer

of H.D.C. Alternative ways would be considered to solve this

problem.

3.2.2 Aluminium Foil and High Density Clear Paste

Target Set: Using kitchen Aluminium Foil in prints to conduct

electricity on textile

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Applying H.D.C on the back

Circuit sealed in H.D.C

Front print showing LEDs and Expanding Binder

Illuminated Print

Details: A layer of H.D.C. was applied on the fabric with a squeegee

via the screen-printing technique using a coarse mesh. Then, the

aluminium foil was cut, folded and stuck to the wet paste. The paste

was dried and a second coat of H.D.C was applied over the first coat

and dried. The Aluminium foil was sandwiched between the two coats

of H.D.C. The LEDs were inserted between the folds of the aluminium

foil.

Target Achieved: A thin transparent plastic print was obtained. The

drape, softness and weight of the fabric were not affected. This

technique could also be used to conduct Direct Current (DC) from one

point to another on a fabric.

3.2.3 Using crushed graphite to make conductive paste 

Target Set: Creating conductive print using graphite that can be applied

on fabric 12

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Aluminum foil cut into shapes

Aluminum foil laid over wet H.D.C Aluminum foil sealed in H.D.C

Details: Graphite were crushed and spread over a printed layer of

wet H.D.C. H.D.C has excellent adhesive properties and is

commonly used in textile for flock and caviar printings.

Target Achieved: Paste was not successful. There were too many

gaps between each graphite particle.

3.2.4 Crushed aluminium flakes to make conductive paste

Target Set: Creating a cheap conductive print using aluminium

powder that can be applied on fabric

Details: Aluminium flakes were crushed and spread over a printed

layer of wet H.D.C.

Target Achieved: The printing paste failed to conduct. Carbon nano

particles were applied on fabric in the same manner and

the results were negative. 14

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Crushing Graphite

Applying Graphite over wet H.D.C

Crushing Aluminum Flake

Mixing Carbon Nano Particles with H.D.C

3.2.5 Developing the Printed Electronic Soft Pad using woven

fabrics

3.2.5.1 Applying the Conductive Printing Paste on woven fabrics

Electrosperse D-112 was purchased from Five Star Technologies,

from the USA. It consists of components like Silver, Terpineol, Ethy

Cellulose and Glass Frit and is very conductive. It is not made to be

used on fabrics.

The best way to apply the paste on the fabric and avoid wastage was

to use stencil printing technique and to apply the paste either with a

brush or a sponge.

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3.2.5.2 Washing Tests with the Conductive Printing Paste

Target Set: Testing the resistance of the print after several wash.

Details: 3 prints with the Conductive Paste were printed on a piece

of fabric. Only 1 coat was applied on the first print, 2 coats on the

second print and 3 coats on the third print. All prints were cured.

Prior to washing, the resistance of each print was measured and

recorded. The fabric was hand washed and line dried. Then the fabric

was conditioned in an oven at 105 degrees Celsius for 4 hours. The

fabric was washed 3 times under the same procedure and each time

the resistance for each print was measured and recorded.

Target Achieved: The test carried out helped to determine the

washability and durability of the conductive paste.

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Rectangular Prints using Conductive Paste (Electrosperse D-112)

Soft switch

3.2.5.3 Designing and making Printed Electronic Soft Pad

Target Set: The soft pad is similar to a board of electronic switches

but made in fabrics, and is soft, thin, light-weight and washable. Each

switch on the soft pad can be programmed to perform a particular task

such as lighting up or playing a tune.

Details: The soft switch consisting of two layers of fabrics was placed

on top of each other.

The circuit of the soft switch was designed and printed on the fabrics.

The two layers were then sewn together and tested.

Target Achieved: The soft switch was connected to a power supply

and each switch was further connected to a LED. The LED would only

light up when a slight pressure was applied on the switch. The soft

switch is very soft, light and with draping qualities. The soft switch

opens up many avenues that can be further exploited.

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3.2.6 Developing the Electronic Label (E-label)

3.2.6.1 Experimenting with High Density Clear

Target Set: E-label is a new and innovative invention and which can be

used in garments replacing the traditional leather, woven or plastic

labels that are used mainly in Jeans (on the waist belt) or on some

jackets.

Details: A circuit, consisting of LEDs and wires, was made and sealed

in high density clear paste and dried at very high temperature.

Target Achieved: The samples could be bent and twisted in any

direction without compromising the connection and it could be washed

and re-used again. The possibility of including the cell battery inside the

E-label with other types of Integrated Switches (IC) was further

explored. The only problem encountered was that after some time, the

H.D.C started to crack. Transparent silicone was used to replace the

H.D.C 20

3.2.6.2 Experiencing with Transparent Silicone Glue

Target Set: Replacing the H.D.C with Transparent Silicone

Details: Transparent silicone was spread in an aluminium mould. A

circuit, consisting of flat square LEDs, electrical wires and 2 metal

clips, were inserted into the wet silicone paste. Connections were

soldered together. A logo was designed, printed on translucent paper

and thereafter inserted in the wet paste and left to dry overnight. After

drying, the silicone was easily removed from the mould. The thickness

of the E-label was 5 mm.

Target Achieved:

Problems encountered with samples:

• The connections broke at several points.

• The thickness of the e-label was 5 mm. It needed to be thinner.

• Smaller LEDs would be considered.

• Electrical wires were not appropriate and therefore using conductive threads was considered.

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3.2.6.3 Experiencing with Transparent Silicone Glue

and using conductive thread

Target Set: Replacing the electrical wire with Conductive Thread and

reducing the thickness of the E-label from 5 mm to 3mm

 Details: The Conductive Thread is a much better choice as the risk of

breaking is less. It can bend in any directions and the connections

can be made by simply tying knots instead of using solders. Three

ends of the conductive threads were twisted together. The circuit was

sealed in the silicone and left to dry.

Target Achieved: A new product, the E-Label was developed ready to

be inserted into any garment in numerous ways. The E-Label would

have to be connected to a power supply which would be inserted in the

garment. The circuit was protected by the layer of silicone and

therefore could easily be washed. 22

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Silicone sealed in an aluminum mould

Circuit made of conductive threads and LEDS

Circuit Sealed in Silicone

Circuit can be twisted, bent and wash without Compromising the circuit

3.3 Conductive Threads

Conductive threads were purchased from the Internet and could be

bought in spool of 200 yards

3.3.1 Simple Experiments using the Conductive thread

 

Experiment 1- Measuring the resistance value of the Conductive

Thread along different length

 Experiment 2- Measuring the resistance value of the Conductive

Thread when a knot was made along the length (to see whether tying

a knot would affect the conductivity)

Experiment 3- Measuring the resistance value of the Conductive

Thread when several ends of the conductive thread were used

together. All results were recorded in a table form.

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3.4 Knitting

Knitting is defined as a cloth manufacturing process in which needles

are used to form a series of interlocking loops from one or many yarns

or from a set of yarns (Hollen et al. 1979, p.183).

For this project two types of flat knitting machines had been used to

knit the samples:

• Industrial V-Beds Knitting Machines

• Domestic Knitting Machines (single bed only )

3.4.1 Knitting with the conductive thread

Five samples were knitted in different structures together with the

conductive thread. Different yarns, such as 100% Lamb Wool, 100%

Wool, 100% Cotton and a blend of 75% Rayon/ 25% PTT, were used

to knit the above samples.25

3.4.2 Laundry TestThe samples were washed at normal temperature (40 Degrees Celsius) and were line dry at room temperature. Thereafter, the samples were conditioned in an oven at 105 degrees Celsius for 4 hours. The conductivity and size of each sample were measured and recorded.

3.4.3 Integrating LEDs into knitted samples

3.4.3.1 Sample 1: Ripples on a 3 X 7 Rib Structure (7 Gauge)Target Set: Varying the knitting structure to make a wearable circuit.Details: Ripples technique was used and knitted on a 7 gauge knitting machine. The conductive thread was used with normal yarn and LEDs were inserted into the knitted sample.Target Achieved: The knitted sample was connected to a DC power supply and the LEDs lit up creating some amazing effects. Furthermore, the sample could be moved, twisted and bent without compromising the connection.

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3.4.3.2 Sample 2: Ripples on a 4 X 4 Rib Structure (5 Gauge)

Target Set: Indentifying knitting structures that could be used to

incorporate and lit the LEDs using only the conductive threads.

Details: A different Ripples Structure was used and knitted on a 5

gauge knitting machine. The conductive thread was used with normal

yarn and LEDs were inserted into the knitted sample.

Target Achieved: The knitted sample was connected to a DC power

supply and the LEDs lit up. Furthermore the sample could be moved,

twisted, bent and this did not compromise the connection.

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3.4.4 Developing the Knitted Electronic Soft Pad

Target Set: Using knitting fabrics to make a soft pad without using

any electrical wires and switches. Two techniques were used namely

the Ripples Structure and the Single Bed Jersey. 

Details: This ripple sample was considered because of the raised

surface created by the Ribs. The idea was to lay the ribs facing

downward on a flat conductive fabric (Single Bed Jersey). The ribs

prevented the conductive thread from touching the fabric underneath

unless pressure was applied.

Target Achieved: The Knitted Soft Pad was tested and the

result was very positive. Sample was very light, soft and could

easily be integrated in garments or furniture.

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3 X 7 Rib Ripple structure, Knitted on a 7 gauge machine

4 X 4 Rib Ripple structure, knitted on a 5 gaugeKnitting machine

Knitted soft switch

4.0 Further Works:

• Developing a cheap conductive printing paste for textiles using powder aluminum and expanding binder.

• Incorporating conductive materials in woven fabrics through different manipulating techniques without compromising the look and feel of the fabric.

• Exploiting other manipulating techniques such as embroidery, appliqué, etc.

• Incorporating the E-Label in garments

• Establishing illuminating prints in garments (E-Print).

• Using the soft switch in furniture and in garments to perform a function.

• Developing products for home interior with some of the ideas developed above.

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5.0 Problems Encountered:

• Difficult to work on research project during semesters.

• Materials are difficult to find especially on the local market.

• Materials are expensive.

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4/06/0004• BERZOWSKA, J. and COELHO, M., 2006. SMOKS: The memory suits: Montreal, Quebec, Canada, ACM 1-59593-

298-4/06/0004• BERZOWSKA, J., 2007. Intimate Electronics: HorizonZero, Issue 16: wear: smart clothes. fashionable technologies• BRADDOCK, S. AND O’MAHONY, M., 1998. Techno textiles: Thames and Hudson, London. Vol 1• BRADDOCK, S. AND O’MAHONY, M., 2004. Techno textiles: Thames and Hudson, London. Vol 2• DUNNE, L. ASHDOWN, S. AND SMYTH, B., 2005. Expanding Garment Functionality through Embedded Electronics

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2 (2).• NEWS OF THE WEEK, 2008. Silicon circuits that fold and stretch. News of the Week, 31 March, p.5a.• NKIWANE, L.C., 2005. Intelligent Textile, University of Botswana. Paper presentation. • PIOTROWSKI, C., 2004. Becoming an Interior Designer: John Wiley & sons, Inc., Hoboken, New Jersey.• POST, E.R., and ORTH, M., 1997. Smart Fabric, or “Wearable Clothing”: IEEE.• RIBEIRO, J.C OLIVEIRA, S.M MENDES, P.M AND CORREIA, J.H., 2001. Wireless Interface for Sensors in Smart

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p.6a.• SMARTTEXTILES and NANOTECHNOLOGY, 2006. Luminescent textiles for new effects in home furnishings. Smarttextiles and

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