You can set up a simple "Is it Conductive?" station for makers of any age to test what items are conductive and what items are insulators! We'll even teach you how to make a wearable experiment in the second half of this Instructables! Makey Makey works by alligator clipping into everyday things that have some conductivity. When you hook an alligator clip into a banana and you hold an alligator clip connected to EARTH, you are actually the conductive stuff that closes the circuit and makes Makey Makey work! But what materials can we use with Makey Makey besides bananas? What does it mean for an item to be conductive? or an insulator? or even a resistor? Let's set up a simple experiment to find out!
|Step One: Create an Experiment Station
Test an item by laying it across the conductive tape traces. If it is conductive, the game will tell you! Sometimes, it helps to use a plastic ruler to press down on the item so you don't accidentally set off the conductive radar with your hands! Label the item in your t-chart as you test them!
Educator set up:
After testing items, discuss why some items are conductive and why some aren't.
A conductor is any item that allows electrons to flow through it with little effort. If an item has any conductivity, Makey Makey will detect it. Most metals are great conductors! Pure water is actually an insulator, once water comes in contact with things like salt, humans, etc, it becomes contaminated. Because of this, free ions in water are what make water conductive.
An insulator is any item that does not allow electrons to flow through it. Things like masking tape, hot glue, paper, are insulators that do not allow electrons to flow.
Link to: "Is it Conductive?" pdf
|Step Two: Create a Wearable Experiment
Create your own wearable "Is it Conductive?" lab coat! Download all these svg files and import them into the vinyl cutter of your choice. We used a Cricut Maker and imported the svg as a photo for cutting! Once you've cut out the text "Is it Conductive?" and the Makey Makey logo use a heat press or iron to adhere the vinyl before you add your circuit paths and LED.
Download the "Circuit Path" svg and import into your cutter's design software. Load a copper tape sheet onto a standard grip carrier to cut the "Circuit Path."
This copper tape sheet works well cut with the depth of a vinyl sticker, alternatively you could use thick one-inch copper tape for your conductivity tester paths.
Files for your vinyl cutter:
|Step Three: Craft Circuit Traces
To craft your circuit traces, use the conductive fabric tape in our Makey Makey Booster Kit to connect one copper path over the shoulder of your jacket to the front pocket. This will be connected to a key press input on your Makey Makey.
Use a new piece of conductive fabric tape to connect the second copper path over the shoulder of your jacket towards the front pocket. Make sure this tape path never crosses the "key press" path. This crafted circuit trace will be connected to the ground or EARTH input on your Makey Makey.
|Step Four: Craft Your LED Circuit Traces
To light up an LED, you have to connect the long leg of the LED to the "KEY OUT" pin on the Makey Makey and the short leg to a GND pin (on the back of the Makey Makey) or you can alligator clip to one of the 5 EARTH inputs along the bottom of the board.
Make sure you test your LED before you sew it to your jacket!
Since you want the LED on the outside of the jacket, you'll push the legs through to the inside. On the inside of your jacket, you can bend the legs with needle nose pliers to make them more sewable. Use some conductive thread to hold it to the jacket and ensure a good connection. Instead of sewing all the way to where you will clip to your Makey Makey, you can use conductive fabric tape to craft your tape traces to the inside of the jacket near the front pocket.
Repeat for the negative leg of your LED. Use conductive thread to sew to the jacket and cover with fabric tape to extend your circuit tape trace. Make sure the positive and negative circuit traces never touch! A good way to protect your circuit near the LED is to use hot glue as an insulator.
If you need to cross one circuit trace over the other, you can actually use masking tape as an insulator.
On the front of the jacket, you might want to give yourself visual cues to help with hook up. You can use conductive thread to make a plus sign on the front side of your jacket. Make sure you sew from the front (or right side) of the jacket to the inside (or wrong side) of the jacket. Also make sure your thread makes a good connection with your positive tape trace. Make sure to sew from the front to the back and into the fabric tape. To ensure a connection, you can place another piece of fabric tape over the thread to sandwich your thread.
For your ground or "EARTH" connection, sew a negative sign on the front side of your jacket with conductive thread. Again, remember to bring your thread through to the fabric tape!
You will need an ohm resistor in your Makey Makey circuit so you don't blow out the LED. To figure out what ohm resistor you need, you have to use Ohm’s Law. That formula is V = I × R, where V is the voltage, I is the current, and R is the resistance.
Check out this table from Evil Mad Scientist.
Makey Makey output is between 4.5 - 5V, so for a Blue, Green, White, or UV LED, you will want to use a 48 ohm resistor.
If you are using a Red, Yellow, or Yellow-Green LED, you will want a 36 Ohm resistor.
|Step Five: Hook Up Makey Makey
To hook up your Makey Makey, put one of the white jumper wires from your kit into the "KEY OUT" pin on the back header. This wire you will alligator clip to the "plus sign" you sewed onto the front of your jacket.
We made some safety pin alligator clips by pulling the alligator heads off and putting on safety pins! Here is a great Instructables to learn more.
Hook another alligator clip to EARTH and the "negative sign" you sewed on your jacket with conductive thread.
This is how you will light up your LED on a key press.
To register a key press when something is conductive, hook one alligator clip to SPACE (or any key press) and one of your over the shoulder "Is it Conductive" tape traces. Then take another alligator clip and hook it to the other tape trace and an EARTH connection on the bottom row.
The last step is to power your Makey Makey! For versions 1.3 and up, you'll want to power your Makey Makey with a USB portable charger. Make sure it has a charge, and then you can just plug your Makey Makey into the USB port!
If you have an older Makey Makey, you can actually power it with double AA batteries. Here is a quick Instructables explaining the process! Basically, you'll put your red wire from your battery pack into the 5V pin and the black wire into a GND pin.
|Step Six: Test Items!
The last step is to test items! Wear your new experiment and make sure to fill your pockets with fun items for testing!
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