Consumer Peripherals

LilyPad Arduino board for e-textile projects

09 December 2022
LilyPad structure. Source: CC BY 2.0

Sewable electronics integrate traditional craft methods in fashion design, sewing and textile design with computer science, electrical engineering and hardware expertise. Electronic textiles, or e-textiles, can be made with sewable electronics; these are frequently soft, wearable creations that resemble art or crafts more than standard electronics. Flexible conductive materials, such as conductive thread and fabric, are used in many e-textile applications in place of wires. To complete the tasks outlined in this article, you'll need to pick up a conductive thread and a LilyPad Arduino board.

What is LilyPad Arduino?

The LilyPad Arduino board is a collection of electronic components that may be sewn together to create soft interactive textiles via sounds, light and sensors. Utilizing LilyPad modules is a terrific way to play with electronics from a craft perspective. Every LilyPad module includes big conductive sew tabs for simple stitching and a rounded form to avoid snagging fabric or cutting thread.

[Learn more about electronic development boards on GlobalSpec.com]

What is a conductive thread?

This type of thread that conducts electricity is woven from strands of stainless steel. It's an alternative to copper wiring that may be used to connect LilyPad (or other e-textile) components to make circuits. A conductive thread spindle is included in LilyPad kits like the LilyPad Sewable Electronics Kit.

How are components secured to LilyPad?

Large holes, or sew tabs, are located in each LilyPad component and are composed of conductive silver pads. There's plenty of room for many needles and thread passes thanks to the wide tab dimensions. Determine which sew tabs you'll need to connect components before you start sewing the circuit and position them where they'll be most convenient to reach.

Hot glue (recommended) or fabric glue can be used to secure each LilyPad module to the fabric before sewing starts; be careful not to close off the holes in the sew tabs. Now that the board has been affixed to the fabric, it is ready to be connected with the conductive thread. To prevent accidentally dragging the conductive thread all the way through the cloth, start by tying a knot at the long end of the thread, as would be done with any sewing job.

Circuit components are joined using conductive thread that is sewn around LilyPad sew tabs. When connecting the thread around an empty sew tab, make three or four loops and draw each loop tight. By doing so, one may be certain that the thread and sew tab have a solid physical and electrical connection. To prevent loose stitches, tighten the loops before proceeding.

How to overcome challenges while making sewable electronics

Be mindful of any loose threads or tails of knots in the project. Short circuits can occur if any piece of conductive thread from the positive (+) side of the circuit contacts the negative (-) side. A short circuit links the battery with itself and skips the rest of the circuit, forcing the battery to consume an excessive amount of current. Additionally, stitching directly across stitches in another section of the circuit might induce a short. It is essential that the stitches do not overlap or contact other components of the circuit. In the event of a short circuit, the batteries used in these designs should just get warm, not burn or shock a person, although more powerful projects or power sources might pose a risk.

[Browse suppliers of Arduino products on GlobalSpec.com]

Alternatives to using a conductive thread

Here are several options that work well for wearables in large projects with many power-hungry components, such as numerous LilyPad Pixel modules; projects requiring a great deal of thread to go great distances, or in locations where thread may break under stress:

  • Traces of conductive fabric: The designer can use narrow strands of conductive cloth to make their own low-resistance lines. It is usually recommended to use iron-on glue to connect components to fabric or ribbon. After that, use conductive thread to hand-stitch components to the traces. Also, it is important to insulate the traces of conductive fabric just like the conductive thread.
  • Conductive ribbon: Another low-resistance conductive thread replacement is a specialty nylon ribbon that has flexible wire weaved into it. However, one can't just cut the ribbon and use it in an e-textile project without first soldering to the tinsel inside.
  • Stranded wire: The use of ordinary stranded wire instead of conductive thread is another option. When compared to solid wire, stranded wire is far more bendable and flexible without the risk of severing or breaking. Since wire has far less resistance than thread, a wire circuit may support many more LEDs. It will need to be soldered to the same sew tabs that are used for passing the thread. In the case of washing projects, exposed stranded wire may be corroded over time if water seeps into it and becomes stuck. To avoid this, just apply some silicone sealant to the wire's cut ends. Soldering might cause neighboring cloth to melt or catch fire, so be cautious. Before applying heat, make sure the LilyPad board is raised off of the fabric backing.
To contact the author of this article, email engineering360editors@globalspec.com


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