Stem Challenge: Greatbatch
This last part of our microcircuit engineering is focused on making a usable circuit. In this example we will use a very easy method to model how micro circuits are made. In this example we will make a circuit board from a film of aluminum foil and then add components using the liquid conductor/resistor from Parts 1 and 2.
This video shows a simple circuit using aluminum foil as the conductor and our resistive paste as both a resistor and glue and a conductor.The pattern you will be using for this circuit is shown below.
The dark areas show a foil conductor. The LED is a light emitting diode that you will attach with your conductive paste. The gap for resistance will be what you have calculated as necessary for a proper electron control for the LED. You will paint this area as needed. The directions below will show how to make the switch.
You will need the following materials to do this part of the exploration:
• Glue stick
• Tag board or thick, stiff paper
• Razor blade or craft knife
• Conductive paste from the first parts of the project
• 9 volt battery and connector
• Light emitting diode (LED)
Step 1. Glue a 2"x 2" piece of aluminum foil to an index card.
Step 2. Using your finger smooth the foil on the paper so there are no wrinkles.
Step 3. Mark out the areas of foil that you want to remove.
Step 4. Using a knife, make a cutting line where you want to remove some of the foil. Carefully strip off the unwanted foil. Remove foil in the areas noted "gap for resistance" and LED and switch.
Step 5. Using the conductive glue, attach the LED to the foil.
Step 6. Paint in your resistor
Step 7. Make a switch by cutting a piece of stiff paper and gluing one side with foil. Attach one end of the paper to the area of the foil shown in the pattern above. Adjust the paper so that it normally does not connect with the other foil square.
Step 8. Attach the battery wires as shown in pattern above. Pay attention to make the black or negative lead attach to the foil that is connected to the flat or negative side of the LED.
Step 10. Test your circuit.
FINAL ENGINEERING CHALLENGE. Using your prior knowledge of circuits, resistances, and technology, engineer solution for one of the following challenges. Design the circuit board and placement of components as well as distances required for resistances. Then follow through on the project by producing a report of your challenge, process, and outcomes. Remember to record all your work in the STEM Notebook.
1) Create a circuit that could determine the polarity of any 9 volt battery.
POLARITY TESTER. UNKNOWN BATTERY
SOURCE AT “A” AND “B”. ONE LED WILL LIGHT
INDICATING THE POLARITY OF THE BATTERY.
2) Create a circuit that would create a Hi/Lo Flashlight. Resistances are chosen to match two levels of brightness.
