I call students to the gathering area. I tell them that today they have an engineering design challenge. I tell them that today, they will design a piece of functional art work. Using the dough that we used in the previous lesson, they will design a sculpture that will either light up or make a sound when pressed. We will be using the dough we played with yesterday.
I tell students that the insulating dough will be very important today in order to prevent short circuits. Students will need to be aware of this and think through their designs before building as it is not so easy to pull the dough apart if you have squished it together.
I make a quick flower design using the insulating dough as my petals. I then make concentric circles of conducting and insulating dough in the center of my flower. This allows me to place my LEDs in a circle around the center of the flower and give it some color variation. I attach the leads from my battery pack, one to each conducting circle. I do this behind the flower so only my LEDs show in the front. I turn on my battery pack and the flower glows.
I tell students that they can make their own variation on mine, or a completely new structure. This allows for scaffolding of the process for those who need more support in choosing what to build, but lets other children have an open-ended process as well. My only restriction is that they cannot replicate mine.
Students work in their pairs to create their sculptures. I monitor the room and help with design and technical questions. My biggest role here is usually how to get the dough to conduct. Since it is not wire, it does not conduct as well. Short, fat sections of dough offer the best conductivity. Also, students can increase conductivity by adding aluminum foil to the ends of their wire leads for a larger surface area.
When students have completed their sculptures, each group presents theirs and describes how they designed and built it. I am interested to see how students were able to troubleshoot issues of short circuiting and how they managed to make their bulb light or buzzer buzz. I am looking for innovative ideas as well as the correct use of terminology.
Students are assessed for creativity of design as well as functionality. This is a difficult task. If students are successful in creating a working sculpture, they have been able to work through the issues associated with building circuits and thus have demonstrated mastery of the content.