Electric Play Dough Project 3: Light Up Your Sculptures!

If you are making a new batch of dough, the best way to prevent these problems is to follow the directions carefully and measure the appropriate amount of each ingredient. Some steps require you to slowly add small amounts of water until the desired consistency is formed, instead of adding the entire amount all at once.

1. Make sure you properly inserted the batteries into the battery pack. Each battery is marked with a "+" symbol on one end. Make sure these symbols line up with the "+" symbols on the inside of the battery pack.
2. Make sure you turn the switch on your battery pack to the "on" position when you are testing your circuit.
3. Make sure your conductive dough is tightly secured around the metal leads for your battery pack. If you wiggle them around a lot and they come loose, then they will not be in good contact, and it will be difficult for electricity to flow.
4. If you have a multimeter, you can use it to measure the voltage from your battery pack. Four AA batteries should provide about 6 volts (V). If the voltage is lower than 6 V, your batteries might be dead. Consult the Science Buddies Multimeter Tutorial if you need help using a multimeter.

1. Remember that LEDs have a polarity, meaning they only work in one direction. The longer LED lead should be connected toward the positive side of your circuit, which is the side with the red wire protruding from the battery pack. If one LED in your circuit is not lighting up, but others are, you probably just have that LED plugged in backwards. Try reversing its direction and see if it lights up.
2. Make sure your conductive dough is tightly packed around the metal leads for your battery pack. If you wiggle them around a lot and they come loose, then they will not be in good contact, and it will be difficult for electricity to flow.
3. Make sure you do not have a short circuit. For more information about short circuits (including pictures and diagrams), refer to the Introduction of the first Squishy Circuits project.
4. If your circuit has two or more LEDs, make sure they are wired in parallel and not in series. Wiring multiple LEDs in series will quickly cause them to become very dim. For more information about the difference between series and parallel circuits (including pictures and diagrams), refer to the Introduction of the second Squishy Circuits project.
5. Make sure you are not using very long pieces of conductive play dough to connect your battery terminals to your LEDs. The conductive play dough has a fairly high resistance, which causes the voltage to drop as electricity travels through it. If you use very long pieces of conductive dough, the voltage might drop so much that the LEDs will not light up. To learn more about voltage and resistance, check out the Science Buddies Electronics Primer Introduction.
6. Never connect your LEDs directly to the battery pack leads without using conductive dough in between. Connecting LEDs directly to the battery pack will cause them to burn out; too much current will flow, permanently destroying the LED. If you have LEDs that do not light up at all despite trying all the steps above, you might have accidentally burned them out at some point.

1. In general, follow the same steps as in FAQ 3. For a big circuit, it is possible to have a short circuit in only part of the circuit; some LEDs might light up, while others stay dark. You might have also accidentally wired some LEDs in series, and some in parallel. Remember to always avoid short circuits, check the direction your LEDs are plugged in, and make sure your LEDs are wired in parallel.
2. You can test individual parts of your circuit, one at a time. You can do this by breaking them away from the rest of your circuit and connecting them to the battery pack separately, or by sticking the battery pack leads into different parts of your circuit. This will let you identify problem areas in your circuit.
3. Remember that it is possible to burn out LEDs by connecting them directly to the battery pack. If nothing else works, try swapping in a new LED.

1. Both types of homemade dough (conductive and insulating) should be stored in air-tight plastic containers or plastic bags. You can put it in the refrigerator to make it last even longer.
2. The conductive play dough contains salt, so will last for several weeks or months if kept in an air-tight container. Eventually, you may still see spots of mold or bacteria growing on it.
3. Insulating play dough contains sugar, which bacteria and other microorganisms thrive on. You may start to see mold or bacteria growing on it after several days or a week, but it will last longer if refrigerated.
4. If your play dough develops spots of visible mold or bacteria, you should throw it away and make a new batch.

1. Make sure you use short, thick lumps of Play-Doh to connect the buzzer to your battery pack. The buzzer requires much more electricity to operate than the LEDs. Long, thin strips of Play-Doh have a higher electrical resistance, making it difficult for enough electricity to flow through them.
2. The buzzers have polarity, just like the LEDs. Their red wires need to be connected to the battery pack's red wire, and their black wires connected to the battery pack's black wire.