I came across conductive ink in my research and as a Design student I started to question its use on my projects.I envisioned a poster with LEDs and typography where light would be an illustration of the text. For this project I chose a Carl Sagan’s text where the LEDs evoke a galaxy.

The complexity of this project would be simplified if the circuit was silk printed but this instructable is perfect if you want to do it yourself at home. Feel free to simplify and adjust these steps for your own poster, card or anything your imagination may lead you to.

## Step 1: List of Materials

tape

pencil

triangle ruler

cutting mat

x-acto knife

paper stock

glue

LEDs

conductive ink (bare conductive)

pin coin battery

pin

(pliers)

## Step 3:

Mark where you want your LEDs, pin them, both points, so that you can insert the LED perfectly in those two holes. Bear in mind:
– because of polarity, LEDs have to always be in the same direction, I decided that the positive was going to be facing the top and the negative facing the bottom of the poster
– if you have two LEDs near each other horizontally, they have to be exactly in the same line, use a ruler to help you in this step.

## Step 4:

On the back of the paper start drawing your circuit:
On the right side I drew the positive, on the left the negative.
Join the holes with the lines, the upper holes with the right vertical line, and the bottom holes with the left vertical line.

## Step 5:

Cover the circuit with conductive ink.
Be careful, the ink shouldn’t touch the other lines or it will cause a short circuit.
The ink takes a long time to dry, depending on temperature and air moisture. Wait a few hours, or even a day, to start the next step.

## Step 6:

Fix your pin battery in a paper and then glue the paper in the bottom part of the poster, where you have no conductive ink. The positive side of the battery must be placed to the right and vice versa.

## Step 7:

Draw the rest of the circuit with conductive ink covering the positive and the negative, save a gap for your switch.
Wait until the ink is dry.

## Step 8:

Cut two rectangles with the same width and with the bigger one make a ring and then fold it.

## Step 9:

Use tape to help you in this step, you’re going to find out where you have to place the stoppers for your switch.
Insert the first stopper inside the paper ring, on the bottom, place it on the poster aligned at the bottom, that will be the final position of the stopper (OFF position).
To find out the position of the upper stopper, you have to place that stopper inside the ring in the upper part, push the switch and that will be the ON position.

## Step 10:

Mark with a pencil where it all must be glued and then turn the switch facing you and then mark the ON position.
You have to draw conductive ink to close the circuit when the switch is pulled down.Wait until the ink is dry.

## Step 11:

Glue everything in it’s right place and reinforce the switch with two stripes of paper.

## Step 12:

The back of your poster should look like this.

## Step 13:

On the front of the poster, start to place the LEDs, each LED should have the long wire in the upright position and the other wire down

## Step 14:

On the back, you’re going to fold the LEDs so that they are in contact with the conductive ink (a pliers might help you).
Once again bear in mind the polarity, the lines that come from the right are positive, the ones that come from the left are negative. To place the LEDs use tape.

Repeat steps 13 and 14 with all your LEDs.

## Step 15:

Now you just have to make sure the LEDs will stay in place.
Using conductive ink, “glue” the positive part of the led to the positive line of the circuit, and the negative part of the LED to the negative line.
Repeat this step with all the LEDs. Wait until the ink is dry.

Enjoy your galaxy on a paper…

<p>Hi there, really nice project! </p><p>I'm actually doing 1 by myself following exactly your steps. </p><p>i tried to do something around A3 size but only manage to lit up to 4-5 LEDs and im using a 12v battery (that should be more than enough), and the lights get gradually dimmer at the 5th LED &amp; totally no electricity on the 6th one... mind to ask what went wrong? </p><p>some question i think i need help on:</p><p>1) the size of your poster &amp; the size of your LED </p><p>2) the thickness of the ink, will that affect the conductivity?</p><p>really appreciate if you can help out here! thanks</p>
<p>Instead of using a small 3V Coin cell, why not use a 2AA or AAA holder instead? Those little coin cells only tend to have a couple hundred miliamp hours on them, and that many LEDs would suck it dry within an hour or two. Also, once painted into place they're a pain to get off and a new one on. You can also find AA or AAA holders with build in switches, which may also be handy for turning something like this on and off.</p>
<p>Hi Joshua</p><p>I used a coin cell because of the volume, I didn't want something strange showing up on the front of the poster. And I've had the LEDs ON for a couple of hours and they're still working. </p><p>But thanks for the suggestion! I'm sure some people will prefer that solution.</p><p>To change the coin cell, you can just unglue the piece of paper where the coin cell is. A x-acto knife might help you with this.</p>
gostei, muito bom!
It's cool!?
doing this for the granddaughter she'll loves the stars and Carl Sagan and she will flip over this
<p>This is excellent! Very cool project.</p>
<p>Thank you seamster!</p>