Paper Circut
 
       
      This project uses copper conductive tape and a coin cell battery to make this light-up card!
Since this project also uses coin cell batteries, it isn't necessary to use a resistor, because they have a higher internal resistance than other types batteries usually do. But although it is a simple project, it is important to be careful when handling and storing small coin cell batteries and keep them away from young children and pets, as it can be a hazard if swallowed.
Feel free to customize it using different colors (or numbers) of LEDs, and experimenting with different designs!
Some other design ideas include:
- flowers with an LED in the center
- Light up animal eyes
- light up cake candle (great for birthday cards!)
- glowing fireflies!
Also, this project, along with many other fun ones, can be found in this book!
Supplies
Circuit:
Decoration:
- paper
- colored pencils/markers for decoration
- tape
- scissors
Connecting the Negative End
 
      Fold your paper in half. Inside, at the bottom, trace the outline of the battery. From there, tape a strip of copper tape.
Connecting the LED
 
      Connect the negative (shorter) leg of the LED to left side of the circuit using copper tape. Connect the positive (longer) leg of the LED to the other side.
Finishing the Circuit
 
      Fold the corner of the paper, so that it overlaps with the outline of the battery. Using the copper tape, extend your circuit and add another strip on the fold.
Inserting the Battery
 
      Tape your battery onto the circle, with the negative end going on the bottom and the positive end on the top. Now, when you fold the flap, the circuit completes and the LED lights up.
Outside Display
 
      On the outside flap of your paper, make a small hole to insert the LED. Optionally, add an indicator for where to press the circuit.
Decorations
 
      Decorate the paper using colored pencils or markers. Try lighting up your circuit!