Although electricity is a common factor in modern life, very few people have a good understanding of how it works. These simple, squishy circuits allow students to explore the concepts of conductivity, insulation, current, voltage, resistance and open and closed circuits. The green dough in the picture above is a conducting dough, made with salt and tap water, that contains ions, which allows electrons to flow. The white dough is an insulating dough with a high resistance, which prevents the flow of electrons. The next time I made this dough, I colored it red, to re-enforce the concept that it stops the flow of electrons. The mass of dough contains two LEDs (Light Emitting Diodes) which are the only connection across the insulating dough. This means that for the electrons to flow from the negative to the positive terminal of the battery, they must pass through the LEDs.
After making the doughs (which is a good exercise in ratio), the insulating dough should be stored in an airtight container in the refrigerator, as it is a good medium for bacteria and fungi to grow. It will last several weeks if stored correctly.
- Squishy Circuits (from the Playful Learning Lab at University of St Thomas) includes recipes for doughs, step-by-step photographs with instructions and simple introductions to parallel and series circuits.
- Squishy Circuits – Play, Invent, Learn. A website with images and videos about squishy circuit projects for children.
- Squishy Circuits from the Exploratorium Tinkering Laboratory – a short blog post that includes a TEDtalk video, reasons to value simple circuits and links to more resources.
- Lesson plan for squishy circuits from UCLA.