Pulsing Keyhole Eye Patch

Introduction: Pulsing Keyhole Eye Patch

About: I'm a crafty otaku book nerd maker parent. While I go back and forth between my artsy and technical sides, I really love to bring my ideas to life.

This project was inspired by the character, Raziel the Red Biblio-princess, from the Japanese anime, The Mystical Archives of Dantalian. Due to the size of the eyepatch, the circuit will be sewed through layers rather than flat on one piece. This can be a little tricky with regards to positioning and also tautness of the conductive thread but still doable.

To make the eyepatch, you will need the following:

4 pieces of eyepatch fabric* (felt was used in this project)

1 Keyhole Embellishment (I got mine from the scrapbook section)

1 LilyPad Twinkle Board

1 LilyPad LED

1 LilyPad Battery Holder

1 LilyPad Slider Switch

18" of 1/4 inch Elastic (in coordinating color)

Conductive Thread

Sewing Thread (coordinating color)

Sewing needles

Strong Glue (that adheres metal to fabric)


small piece of vellum


* I created a template for a whole sheet of eyepatches and laser cut the felt but you can easily cut it with a scissor. The eyepatch shape isn't completely symmetrical. I tried to take into account the contours of the face and have it lay more naturally. If you use the template file I provide, be sure to check the orientation of each layer to make sure it matches up right. You only need one sheet of felt for all four layers.

Step 1: Setting Up the Keyhole

In this step, we will be cutting out the keyhole through two layers of eyepatch fabric. Why two? It'll help give more depth to keyhole. The first layer will be for the keyhole embellishment. The second layer will house the LED as well as the vellum to diffuse the light.

Take the first eyepatch piece and lay out the keyhole embellishment to your liking.

Then mark the keyhole position with chalk.

Remove the embellishment.

Get a second eyepatch piece and line it up with the first.

Cut out the keyhole through both layers but keeping the second layer a little smaller.

You'll need to attach your LED to that layer and it can't be bigger than the hole.

Once that is done, glue down the embellishment on the top layer, making sure you've lined up the keyholes in both the embellishment and top eyepatch layer.

Then set it aside to dry.

Step 2: Setting Up the Front of LED Layer

We will be setting up the second layer to help give a more diffused look when the LED is on. In this case, I wanted a yellow LED but only had white. So, with a yellow permanent marker, I had tinted the vellum yellow.

Lay out the second eyepatch piece that you have just cut the keyhole.

Be sure to have the front of this piece facing you.

Cut a small piece of vellum just a little bit larger than the keyhole.

Glue down the top and button of the vellum and set to dry

(You can also use Glue Dots and forget the drying time. This layer will not be seen and serve as a light diffuser)

Step 3: Setting Up the Back LED Layer - LED and Twinkle Board

You will be positioning the LED and the Twinkle board on this layer. It will be on the other side of the second layer. The positioning is done to compensate for how all the components will lay once it is assembled. I tried to position and orient the components so that sewing the connections won't be a huge mess while trying to keep the eye patch comfortable for the wearer.

Once the glue has dried on the second layer, flip it over to the other side.

Position the LilyPad LED (positive end on top) with the LED facing down into the key hole.

Position the LilyPad Twinkle board in the upper left side.

The board should be facing up at you.
Orient the board so that the 0 (zero) hole is close to the positive end of the LED

Thread your needle with conductive thread and make the following connections.

  1. Connect the positive (+) end of the LED to the 0 port on the Twinkle board. Tie off ends.
  2. Connect the Ground (-) end of the LED to the Ground (-) port on the Twinkle board. Tie off ends.

Set this layer aside and we will start to set up the next layer before connecting these two layers.

Step 4: Sewing the Battery and Switch Layer

This layer will house the battery holder and on/off switch. Separation between this layer and the next will help prevent shorts from happening between the LED layer and this layer. The components will be facing you but staggered in such a way so that it doesn't create unnecessary bulk from the LED layer.

    Take the third eyepatch fabric layer with the back side facing you.

    Position the LilyPad battery holder on the upper right side.

    Then position the LilyPad Slide Switch component on the lower left side as close to the edge as possible.

    Sew a connection between the the switch and the positive (+) connections on the battery holder.

    Tie off the ends.

    Now comes the tricky part: sewing the the circuit between layers.

    Step 5: Finishing the Circuit Between the LED and Battery Layers.

    We will be making the final connections between the two layers. The other end of the switch will be connected to the positive (+) port on the LilyPad Twinkle. The ground (-) will be connected from the negative port (-) on the LilyPad Twinkle board to the negative (-) ends of the battery holder.

    When sewing through the layers and to the ports, keep the thread as taut as you can. This is tricky but the stability of your circuit will depend on it.

    Line up side by side the LED layer and Battery Layer with the components facing you.

    Take the LED Layer first

    Sew the loops through the negative (-) port on the Twinkle to secure that end of the connection.


    Line up Battery Layer and pierce through the layer with the conductive thread and needle from the LED layer.

    Now sew your connection to the negative holes on the battery holder. KEEP THE THREAD TAUT.

    Tie off the ends.

    Back to the LED layer, sew the loops through the positive (+) port on the Twinkle board.

    Then, pierce through to the Battery layer and connect the other end of the switch.

    Tie off the ends.

    You are almost done. Now for the finally assembly.

    Step 6: Final Assembly

    You are almost done!

    Now, it's time to put all four layers together and the elastic band.

    Lay the Keyhole Embellished layer with the embellishment faced down.

    Position the ends of the elastic with 1/4 in inside the layer. Pin it down

    Lay the LED and Battery Switch Layers down on top. The Battery layer should be facing you.

    Lay the fourth eyepatch piece on top.

    Pin the edges to hold the layers in place.

    Sew with regular thread to secure the layers and the elastic.

    Leave openings to for the switch and the battery to make it accessible.

    Add the battery.

    You are done!

    For the whole ensemble, you can make the necklace with with the key or something for your chosen key keeper. But that's another Instructable.

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      8 years ago

      Your eye patch is very clever. I make bullet necklaces with a crystal on the end. I want to put an led light inside the empty shell. I don't know who to contact and wondered if you could help me out. Thank you


      Reply 8 years ago on Introduction

      Hi, I'd love love to help. I've sent you a PM asking more specifics about your project. Best regards!


      8 years ago on Introduction

      super clever, thanks for sharing this with the Instructable community!