E- Textiles 'How to' Tutorials

What is e-textiles?
E-textiles refers to the use of electronics in textiles products to add functional or decorative effects. They are sometimes called electronic textiles and wearable electronics.  There is no soldering and you just need basic sewing skills and a very limited knowledge of circuits.

What components do I need to create a circuit?
To create a basic circuit you need a cell holder (the power source), a cell (battery), an LED (there are 2 types, a PCB one or a traditional LED with wire legs) and conductive thread to join it all together.  

I am just starting out using e-textiles; what components should I buy?
Keep things simple until you understand some of the basic trouble shooting tips, especially if you are a teacher doing e-textiles in a classroom. A cell holder with a switch is the easiest to use as you haven’t got to think about adding a switch to your circuit. The PCB LEDs are the easier to use than the standard ones with the wire legs as they have the negative and positive marked on them and there is no fiddly leg twisting to do. 

What other equipment will I need?
You will need a large eye needle to use with the conductive thread. You will also need round nosed pliers to twist the legs on the LEDs if you are using a standard LED. Having a bin handy is essential to have somewhere to get rid of the bits of thread you cut off as they can short out your circuit.

Are the components safe?
The components that are used are specially designed for use in textiles products. You can’t get electrocuted, they don’t produce heat and there is no fire risk. For more information on safety contact the company who is supplying your components. 

In the tutorials some components have green boards and some white, what do the colours mean?
The green is a traditional colour used on the boards. White boards are a more recent development that are designed to be less obvious under textiles materials. The colour of the board makes no difference to the function of the component. 

What do the plus and minus sign on the LEDs and cell holder mean?
These indicate the polarity of the component. When creating a circuit you need to connect one positive connection on the cell holder to the positive on the LED. The negative on the cell holder and LED also match up. There are additional holes on the cell holders and these can be used to create an additional circuit if needed. If an additional circuit is not needed these holes can be left unstitched or held down with ordinary thread. 

What are the holes on the boards for?
The holes enable you to sew the components onto the fabric. Holes with metal rings around them are conductive and they are stitched using conductive thread to create a circuit. When choosing components from a company choose ones that have large holes in them as they will be easier to sew. You need one positive hole and one negative hole to create a circuit. Some cell holders have two positive and two negative holes which means you can create 2 circuits off the same component. If you don’t need the second set of holes they can just be stitched down using ordinary thread.

What is the difference between a PCB and standard LED?
A PCB (printed circuit board) LED had the light source mounted onto the board. It also has the negative and positive connections marked on the board and there are no fiddly legs to twist. This therefore makes it easier to use. A standard LED has wire legs that have to be twisted into loops so they can be sewn onto the fabric. They are fiddlier and it is easy to forget which leg is which once they are twisted. They are however cheaper and available in a wider variety of colours and types.

What type of batteries do the cell holders take?
The small cell holders use coin cell batteries which can easily be bought from supermarkets and high street stores. 

How long will a battery last?
This depends on how many LEDs are attached and how long the LED is left on for. It might also depend on the quality of the battery itself and how it has been stored. Batteries left switched on all the time with one LED will last for at least 10 hours and will often run for much longer than this. 

How many LEDs can you attach to a battery?
This depends on a variety of factors, including what type of LEDs you are using and how far apart they are. You can attach from about 3-6 LEDs to one battery. You may find you can attach more but the light will be dimmer and the battery won’t last as long. 

How far apart can the LEDs be?
This depends on a variety of factors, including how many LEDs you are using. The closer the LEDs are the brighter they will be. The recommendation is that your circuit should be no longer than about a metre for it to be effective. 

How do I identify the negative leg on a standard LED?
The longer leg is the positive and the shorter leg is the negative. Just above the negative leg on the side of the bulb you can feel a flat surface (like the edge of the bulb has been cut off) and this can also be used to identify the polarity of the LED. You can mark one of the legs to help you remember which it is. I have a rule that I always twist and stitch the negative legs on a circuit before doing anything to the positive side as that way I can’t get confused.

Can the circuits be washed?
Components are sold by suppliers as not being washable but I have washed circuits with cell holders, LEDs and conductive thread successfully by hand on a cool wash (always remove the battery). You should do your own tests before doing this yourself. Bear in mind that the rubbing done during washing might loosen or damage your circuit. If your item will require washing the best thing to do is create a part or whole circuit that can be removed from the product. A cell holder, for example, can be stitched onto a separate piece of fabric and attached with poppers, and this will make it removable for washing. 

Do I just push the LED through a hole I have cut in the fabric?
If you are using a non fray fabric you can simply cut a hole and poke your LED through it. On fraying fabrics this will give a messier finish so you should neaten the hole before putting the LED through it e.g. buttonhole, metal eyelet, gap left in a seam. The legs on the standard LED will poke through some fabrics without breaking the threads. The LEDs will also shine through many fabrics without a hole being cut at all. 

Can I just attach the LEDs to any side of the cell holder?
To create a circuit you need to identify one positive hole and one negative one and these are attached to the corresponding sides of the LED. There may be additional holes on a cell holder and these are for additional circuits. The additional holes don’t have to be used and can be left unstitched or held in place using ordinary sewing thread. 

What do I need to think about when designing with e-textiles?
This will depend on the project and the type of circuit but things to consider might include: Where will you put the LEDs? How will  you get them through the fabric? Where will  you place the battery? Will access to the battery be required? Will the product need washing? 

What are microcontrollers and programmable components?
These are components that can be programmed to behave how you want them to rather than just doing one thing. For example, rather than buying lots of coloured LEDs you can programme the LEDs with the colour you want them to be, as well as making them flash, respond to light and other stimulus. We mostly use Crumble, micro:bit and Igloo in our courses (as well as other microcontrollers, but these are the most popular). All of these can be used with e-textiles as well as being suitable for general electronics uses. ​