Electric Play Dough Project 3: Light Up Your Sculptures!
AbstractHave you tried our first and second play dough circuits projects? Are you a master circuit artist, ready to try something even bigger and better? Try this project to see if you can build a three-dimensional light-up sculpture.
Ben Finio, PhD, Science Buddies
This project idea is based on research done by Dr. AnneMarie Thomas at St. Thomas University.
- Play-Doh® is a registered trademark of Hasbro Inc.
Recommended Project Supplies
ObjectiveUse Play-Doh® and modeling clay to create a three-dimensional sculpture that lights up.
In Project 1 of our project series, you learned about open, closed, and short circuits. In Project 2, you learned the difference between series and parallel circuits, and the best way to hook up multiple LEDs to your creations. If you need to review this information, you can go back to the Introduction section of the Light Up Your Play Dough! and Add Even More Lights science projects. You can also review the Electricity, Magnetism, & Electromagnetism Tutorial to learn more about electricity.
In this project, there is no new information to learn about circuits. Instead, you will apply what you have already learned to light up a three-dimensional structure. This is what engineers do; they apply scientific concepts to build interesting, fun, or useful products. A couple of important reminders before you get started: Remember that you need to attach your LEDs in parallel so they will all light up brightly, and you need to use layers of modeling clay (or homemade insulating dough) to prevent short circuits. But beyond that, there are no rules; your imagination is the limit!
To help you get started, check out the "frog" example:
Figure 1. Example of a three-dimensional play dough circuit creation: a frog with LEDs for eyes.
The secret to lighting up the frog's eyes without creating a short circuit is to use a layer of modeling clay to separate the frog's back from its belly and feet. This is shown in Figure 2.
Figure 2. The frog is made out of two separate pieces of Play-Doh: one for its back and one for its belly and feet. These are stuck together with a layer of modeling clay. Each LED then has one end plugged in to the top layer, and one end plugged in to the bottom layer. This creates a parallel circuit, and the eyes light up!
Now, it's your turn! Let your imagination run wild—animals, buildings, land forms, people, and more—and most importantly, have fun with it!
Terms and Concepts
- Open circuit
- Closed circuit
- Short circuit
- Series circuit
- Parallel circuit
- Do you remember the difference between open, closed, and short circuits? Which kind do you need for your LEDs to light up?
- Do you remember the difference between series and parallel circuits? Which one will make your LEDs brighter?
If you need review, here are the circuit references from the previous science projects in the electric play dough series.
- The Physics Classroom. (n.d.). Requirements of a Circuit. Retrieved February 8, 2013.
- The Physics Classroom. (n.d.). Series Circuits. Retrieved February 8, 2013.
- The Physics Classroom. (n.d.). Parallel Circuits. Retrieved February 8, 2013.
- University of St. Thomas Squishy Circuits Program. (n.d.). Series vs. Parallel Circuits. Retrieved February 8, 2013.
Electric Play Dough Kit
available for purchase from our partner
Home Science Tools.
- 4xAA battery holder
- Piezoelectric buzzer
- Jumbo LEDs (25 total — 5 each in red, green, white, yellow, and blue)
- White insulating dough (3.5 oz)
- Red, blue, and green conductive dough (3.5 oz each)
- AA batteries (4, not included in the kit).
- Optional: in addition to the dough included in the kit, you can make your own conductive and insulating dough (for example, if you want other colors). See Electric Play Dough Recipes for materials and directions for making your own dough. You can also use store-bought Play-Doh® (replaces conductive dough) and modeling clay (replaces insulating dough).
- Optional: if you are making your own homemade conductive and insulating dough in addition to using the dough in the kit, follow the instructions on Electric Play Dough Recipes.
- Insert the four AA batteries into the battery pack that came with your kit.
- Now, plan out the three-dimensional creation that you want to make and how you want to add lights. It might help if you sketch your design on paper. Remember that you need to connect your LEDs in parallel, and that the actual shape of the Play-Doh does not matter, as long as each LED has its own "loop" formed with the battery. You might need to use modeling clay in some places to prevent a short circuit. Once you have a plan, start building!
- Can you cleverly design your sculpture so the LED leads are not showing? How can you cover them with the right type of dough (conducting or insulating) to hide them without creating a short circuit?
- Are there size limitations on your sculpture? Do the LEDs get dimmer if they get too far away from the battery pack?
- If your LEDs do not light up, remember to try reversing them, because electricity can only flow through them in one direction. Also make sure your battery pack is turned on. If you are having trouble, consult the FAQ for other tips and tricks.
For troubleshooting tips, please read our FAQ: Electric Play Dough Project 3: Light Up Your Sculptures!.
Ask an Expert
- Curious about the chemistry behind this project? Research what ingredient or ingredients make the homemade doughs conductive or insulating; then try changing the recipes to see what it does to the conductive and insulating properties of the dough. For instance, how much salt do you need for the play dough to conduct electricity?
Frequently Asked Questions (FAQ)
This guide contains answers to some frequently asked questions for the "Squishy Circuits" project idea series:
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.
- 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.
- Make sure you turn the switch on your battery pack to the "on" position when you are testing your circuit.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- If your play dough develops spots of visible mold or bacteria, you should throw it away and make a new batch.
- 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.
- 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.
If you like this project, you might enjoy exploring these related careers:
Contact UsIf you have purchased a kit for this project from Science Buddies, we are pleased to answer any question not addressed by the FAQ above.
In your email, please follow these instructions:
- What is your Science Buddies kit order number?
- Please describe how you need help as thoroughly as possible:
Good Question I'm trying to do Experimental Procedure step #5, "Scrape the insulation from the wire. . ." How do I know when I've scraped enough?
Good Question I'm at Experimental Procedure step #7, "Move the magnet back and forth . . ." and the LED is not lighting up.
Bad Question I don't understand the instructions. Help!
Good Question I am purchasing my materials. Can I substitute a 1N34 diode for the 1N25 diode called for in the material list?
Bad Question Can I use a different part?
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