BS in Materials Engineering
Materials Engineering Department
The SciTechatorium (SciTech) is a museum filled with interactive exhibits for visitors to learn science informally. A new exhibit was developed to explore electric conductivity and circuits. The design was made based on the size of the material sample the students will use and to allow interactions with multiple users. The materials the students will use were selected using Cambridge Engineering Selector (CES) to sort the materials by resistivity, the inverse of conductivity. After sorting the materials by resistivity, five different materials (balsa wood, polystyrene, polyester, stainless steel, and copper) were chosen for the exhibit. The target size of the materials was 6 x 0.75 x 0.25 inches. The size of the materials is thin enough for the children to hold, but large enough to be easily visible and handled. The frame of the exhibit was made to be 36 x 24 inches to provide ample space for students and to incorporate four independent circuits, two parallel and two series circuits. A light emitting diode and an ammeter were added to provide students with a qualitative and quantitative method of verifying the conductivity of the materials. Since metal is a good electrical conductor, a 220 Ω resistor was added to the circuit so that the current going through the LED does not exceed 30 mA and burn out. The 6 V power source is used and will not be able to shock anyone. A complete prototype was made from plywood to observe student interactions before the final product is made from transparent acrylic so the students will be able to see the circuit wiring. The observations from the interaction with the prototype guided the modifications of the final design.