Preparation for fun:
I made 4 batches of conductive dough: purple (left over from our trial-run of Squishy Circuits), blue, green, and yellow. I also made 3 batches of the insulating dough, without color. Per Squishy Circuits recommendation, I purchased small Safety Glasses from Amazon (affiliate link).
I bought out two local Radio Shack's inventory for buzzers and vibrating motors to end up with 5 of each. These were great because they already had wires on them. Less work for me!
I bought 10 of the 4-AA battery holder with snap connector from Fry's with the 9-volt snap connector. This was also great since I didn't have to solder wires, and I can remove the snaps and store the battery packs without worrying about shorts.
John and I crimped terminals (not exactly what we used, but think something like this) onto each wire. This allowed greater surface area contact for the connections. We also hot glued where the wire connected to the crimped plastic to reduce the pull-out possibilities (kids are hard on things). We also hot glued the joints of the LEDs after we broke one during our trial-run.
All of this preparation paid off. We didn't break the legs of any LED and no wire was pulled out from the crimper. Since everything survived, I now have a classroom set of small electrical components.
The table set-up:
I put down a plastic disposable tablecloth. This helped keep the play dough from acquiring dirt and other park related gross things. Safety glasses were required to participate (provided by us).
Reminder about circuits and shorts:
The battery does not liked to be plugged into the same piece of play dough. There needs to be space or insulative dough between at least two separate conductive dough pieces.
We briefed everyone on "shorts" and how to prevent them. I also made wearing the safety glasses mandatory. We, thankfully, didn't have any shorts.
Totally awesome creations:
I did a happy face (the "hot dog" circuitry is on the underside and the wires stick through the insulative dough to the conductive dough underneath):
Doggy wagging his tail, a vibrating motor (by my husband, John- note the tail flying off at the end):
A few butterflies:
A rocket ship:
A train (that whistled):
Problems we encountered:
The biggest problem was that the dough dried out as we were playing and wasn't conducting well. Reforming/reworking the dough or switching the connector locations solved this problem.
The sunlight drowned out the LED lights, but if we cupped our hands over the play dough circuit, creating shade, the lights burned bright.
During the experiment, we shorted 2 LEDs. Lesson learned: don't connect the LEDs directly to the battery wires. They need resistance which is provided through the play dough.
Please note that due to crazy May scheduling, we will not hold a Science Saturday. We are tentatively thinking about repeating Stomp Rockets for June, with a date TBD.