Introduction: Matariki Paper LED Circuit
Matariki is the Māori name for a cluster of seven stars also known as the Pleides, or the seven sisters. In New Zealand the rise of Matariki marks the beginning of the lunar new year. 2016 celebrations start on June 2nd and continue through to the 26th.
Here is a fun papertronics activity that can be run as part of a classroom or community event, we have made one printable page with 2 circuit templates on it if printing out multiple copies.
Safety first! Any 3mm LEDs can be used but it might be a good idea to check the brightness first, we don't want to hurt anyones eyes. The circuit is powered by a CR2032 coin cell battery but these are very dangerous if swallowed when active - it's a good idea to talk about this at the beginning of the activity - keep them out of reach of small children and pets in particular.
OK let's get started...
Step 1: Materials and Tools
Paper template printout download pdf 1-up on page, or 2-up on page for a class.
Sheet of A4 black card, we got some from Warehouse Stationery
A 3V coin cell battery, we used a CR2032. They are usually cheapest from $2 shops or Aliexpress
Double sided tape
Needle nose pliers
2 alligator clips for testing
A pin or something pointy to make holes
A dry flat kitchen sponge to back the card when piercing it.
Step 2: Prep the Template and Card
1. Cut around the edge of the grey dotted lines on the printed template. Fold up the battery holder tab between the + and - battery contacts.
2. Fold the black card in half. With the card fold at the top, place the template so the battery fold is right at the bottom edge, and centred.
3. With the pin pierce 7 holes in the centre of each of the blue circles, keeping the template in place on the card. tape down loosely with masking tape if it helps. This is our constellation!
4. Now flatten the black card and put adhesive tape on the back, and position inside card so battery fold is aligned with bottom edge of card, and centred. When you fold the top of the card down the holes should align with the blue dots underneath.
Step 3: Prep the LEDs
1. With a permanent marker, mark the top of the long (+) leg of each LED. This is to help us remember which is positive (+) and negative (-).
2. Take one LED, bend the legs like they are doing the splits, and the LED base will sit flat on the paper. It helps to use the needle nose pliers.
Step 4: Copper Circuit Tracks
Now we will stick down all the copper tape so that the yellow (+) and pink (-) tracks on the paper template have all turned copper! Cut pieces the length of each line segment, and overlap them at ends so that there is an unbroken track for the electrons to flow through. The yellow and pink tracks must not touch each other.
1. Starting at the battery terminal at the beginning of the yellow track, cut 2 short (1cm each) pieces of tape to cover the square contact and stick down.
2. Cut a 2.5 cm piece to cover the next section and stick it down, overlapping the previous tape.
3. The next section is about 12.5cm, use the yellow line as a guide. Continue measuring, cutting and sticking in this manner until all of the yellow positive trace is covered in copper.
4. Repeat process for the pink negative track.
Step 5: Tape Down the 1st LED
Remember how we marked the positive leg of the LEDs? This is important to remember now as we connect them to the circuit tracks.
1. Take an LED and place over the 1st blue dot, making sure the positive (marked) leg is touching the (+) track and the negative leg is touching the (-) track.
2. Cut 2 short pieces of copper tape and use to tape down the legs on top of the copper tracks.
3. To test that it works, place the battery (-) side down on the negative terminal and fold the positive terminal tab over it, and hold down. The LED should light up.
4. What if nothing happens? The first thing to test is polarity. LEDs are diodes, and current will only flow through them in one direction, from the (+) terminal of the battery, through the (+) leg of the LED, through the (-) leg of the LED, to the (-) terminal of the battery. Try flipping the battery around, and if it lights up now, then the LED might need to switch direction.
5. No light at all? Check that the copper tape on the tracks are overlapping and taped down firmly. Also push down on the legs to see if they are getting enough contact with the copper.
Step 6: Tape Down the Rest of the LEDs
1. If the LED legs are too long and hang over the edge of the tracks, use the wire cutters to snip them off.
2. Repeat the previous step, sticking down all seven LEDS where indicated on the template making sure the polarity of the LEDS and the tracks are in sync.
3. Test the circuit with the battery. If any don't light up, check the polarity and contact like in the previous step.
4. To keep the LEDs on, hold the battery in place with the paperclip.
Step 7: Enlarging the Pinholes and Finishing
Using a fine electronics screwdriver or knitting needle, widen the seven pinholes on the front cover just enough so that the light shines through.
The card should be able to stand on it's own, or for a wall piece you can seal the edges with tape so the light only shines through the holes.
Ngā mihi o te tau hou! (Happy new year!)