Swatch Making

in progress

intro

Making swatches for e-textiles.

The goal is to provide examples for simple and more advanced circuits on fabric.

The possibilities to make "soft" versions of electronic components like switches and battery holders.

preperation

Table with tools

Putting a special spool with conductive thread inside the sewing machine.

Lock Machine

Table with swatches

tools

Machines

• Sewing machine
• lock machine
• soldering station

• scissors
• needles
• stitch undo tool

electronics

• leds
• coin cell batteries

led conductive thread connection

Connecting the legs of the LED to the thread is always a bit of a problem.

There is a method making an eyelet of the leg of the LED and knotting the thread.

I trepide out a new way for me, with a small clamp:

materials

• non conductive materials
• conductive materials

• vlisofix plus aluminium foil

conductive threads

There are many different conductive threads. Some like the Karl Grimm silver thread can be soldered. Most others, which have a plastic kernel cannot be soldered.

For using conductive thread in my Janome sewing machine I have to change the bobbin holder. I then can put the stainless steel conductive thread in the spool.

All conductive threads have different properties. The most important property for the use in a circuit is the resistance. The resistance of a conductive thread can vary from very little (say less then 1 Ohm every 10 centimeters) to very high resistance, sometimes even kOhm or mOhm.

One of the swatches shows 6 different conductive threads.

On school we only have the stainless steel, which consists of steel fibers around plastic fibers. When you wash this thread it gets corroded, and will break down.

Many conductive threads can only be bought industrially and are not available for small consumers.

It is interesting to look at the conductive thread under the USB microscope, then you get a better understanding of the structure of the materials and you can understand why some of these threads break down easily.

conductive thread 1: Stainless Steel, 4 ply, the school material.	conductive thread 2: Karl Grimm, can be soldered, silver, head to get, the least resistance	conductive thread 3: Elinox, high resistance.	conductive thread 4: Pes Det, the winding of the conductive metal is very conspicuous	conductive thread 5: Wool + steel, lots of wool and the single steel fibers, in this sample most of the resistance	conductive thread 6: Bekinox, feels very heavy
resistance: 5.0 Ohm per 10 centimeters of the sample	resistance: 0.5 Ohm per 10 centimeters of the sample	resistance: 90 Ohm per 10 centimeters of the sample	resistance: 18 Ohm per 10 centimeters of the sample	resistance: 420 Ohm per 10 centimeters of the sample	resistance: 1.0 Ohm per 10 centimeters of the sample

Copper wire

This is used for winding coils. It is isolated, although you "see" the copper. It is called enamelled copper wire. To be able to solder or connect this wire you have to scrape the enamel from the wire, using a knife or sand paper.

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The enamel and the copper can be seen in this picture. The wire in the coil had to be repaired, it had to be scraped to be able to solder it.

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The soldering material will only stick where the enamel is removed. Here the soldiered joint can be seen under the usb-microscope.

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That is why in a knitting of this wire, there is not a short-cut (if the enamel is not damaged).

ideas

• fabric battery holder
• making a circuit
• connecting a LED
• making a textile switch

Failures

I especially also add the failures. Otherwise it would seem that everything fitted without any effort, which is not true. Sometimes failures are more interesting than results. Failures do keep you moving while results are finished - dead.

From these what we call errors you learn the most. For example, I thought I would get a better connection by making the stitch length smaller. But then the stitching on the heavy material gets irregular.

That induced me making a swatch of the different stitch length. It turned out that the default stitch length of the machine 2.4 mm was the best. I also tried out some decorative stitches, and the zig zags.

Starting to add embroidery, things got wrong. This is the material which reminds you of the difference between your lofty ideas and the materials. If everything would go smooth and without any hiccups, no jumps would be made, everything would remain the same. Jumps on the other hand cost time. Maybe time is being made by the failures and the jumps.

Starting embroidery combined with conductive thread, things didn't came together...

The loop in the wire of the fabric speaker....somehow, in the middle of the windings, a loop was formed at the other side of the fabric, resulting in 2 cm of wire which had to be removed.

fabric battery holder

The last battery holder I made functioned, but is was also a bit inconvenient, because it was cumbersome to get the coin cell out. It was too stiff and has only one entrance.

Therefore I designed another way, a battery holder with two sides open. The base fabric holds a pattern of conductive thread and is for the larger + side of the battery. The fabric on top has a nudge of conductive material that pushes on the - side of the battery. There is of course a loop going on the outside to the minus, preventing a short cut.

nudge on top of the fabric made with a zig zag three times on top of it.

With a needle the wire has to be pushed through the material, otherwise there will be a short cut.

Placing the upper side of the fabric battery holder.

The piece is sewn on the base fabric using a zig zag, so that we don't have to fold the side again.

Connecting the wire to the wire of the circuit.

Intermediate stages

Because the sewing machine has a special spool cylinder for the conductive thread installed, the fabric battery holders have to be made later.

Simple circuit, with one LED. The corner fold is the switch.

Circuit with two LED's in parallel.

results

Swatches with conductive thread.

The first swatch is trying out the conductive thread, as can be seen, in plain stitching, when the stitch length is too small, the stitch gets irregular at this fabric.	Sample swatch for different conductive threads. Description above.

Swatches about circuits

A simple circuit. In an electronic sense, this is very simple. For e-textiles, there are already problems to be solved, like sewing the conductive thread and the soft battery holder.	A Parallel circuit. To be able to make two LED's shine, both LED's must be connected to the plus and the minus. E-textile problems: connecting the conductive wire by sewing.	A switch circuit. With the with made of fabric and aluminium foil either the right or the left LED can be chosen.

This circuit exploits the fact that the coin cell battery can be inserted in two ways and that the LED is a diode. Depending on the orientation of the battery either the blue or the red LED will light up.	schema of the two led-diodes. It is the basics for Charlie Plexing circuits, where there are more LED's connected to a microcontroller than free legs available.	This effect can be used for story telling, as is shown in this swatch. The men either fight with their fists or kick with their feet.

Testing the simple circuit

Testing the parallel circuit.

A Fabric Switch

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The Soft speaker

A soft speaker can be built, by using conductive wire and a magnet, in combination with a 555 timer circuit with LDR, with a 9V battery.

The sound is really soft! The tone is varying according to the light on the LDR.

The schema of the circuit: https://cdn.makezine.com/uploads/2014/08/555ss_bboard_4-3-ratio_annotation.png

The circuit on the breadboard.

Three versions of a soft speaker. To the left: copper wire, in the middle, spiral of copper sheet cut with a lino cutter. To the right the conductive metal wire. The problem with this is that the metal "sticks" to the magnets.