Great for egg scavenger hunts, egg hunt periodic table bingo contests or for winning door prizes. Some of these radioactive elements are pretty rare and have a short half-life.
Step 1: Safe Handling of Materials...
This project is just rigging up eggs with LEDs in a repeating fade pattern controlled by a microprocessor like an Arduino.
The egg carton is used to hold the eggs and the magic Arduino is hidden in the package.
You can go with a whole egg or have it hard-boiled but I just used an empty egg shell since that would diffuse the LED light better and not be as opaque.
A little bit of fiberfill is stuffed inside the eggshell for better light distribution.
I used an Adafruit Flora microprocessor board and battery pack.
I used LEDs in different colors with appropriate resistors soldered in line.
Know how to wire up and program your microprocessor.
CAUTION: Know how to safely work with electronics and raw poultry products. If you don't know, ask.
Step 2: Make It Glow...
I looked up the specs of my LEDs, max current draw, forward voltage, and power supply voltage. I plugged those numbers into an online LED calculator to give me a resistor value to use. Resistors prevent the LED from burning out due to a surge in current.
I soldered my own wiring harness with LEDs and resistors soldered and insulated with some masking tape. The masking tape forms well over tiny components and provides some strain relief when handling the LEDs.
I used pairs from a strip of ribbon cable.
The ends of the leads are soldered to male header pins. I like to do this as a breakout cable for my components that plug into the female header sockets soldered to the Arduino. It makes connections and troubleshooting easier.
I am running the basic example of doing a PWM fade of LEDs. It is looping and issuing the command to up the voltage level on each pass and delay to make it appear brighter and then go in reverse to fade out. Each LED is on its own PWM or analog capable pin.
Continually test each step of the way. I adjusted the timings to what I thought looked like a good effect.
More complicated looping could have made each egg individually fade in and out on its own cycle.
Of course, you can also add a light sensor, tactile switch, or ultrasonic range sensor to detect if the carton is open or not. Hook up a piezo speaker to have it click like a geiger counter, more intense if you get closer to it.
Step 3: Christmas Lights...wait, It's Easter Time...
I had taken a sharp knife to poke into and dig out a piece of the shell at one end. Hold it with a towel as the sharp knife tip slips on impact and you really can't saw an egg shell open.
I didn't really figure out which is the preferable end to cut, the wide bottom or pointier top. There is an air pocket with the membrane that hangs off the shell in one end.
I then broke the yolk inside and drained the contents of the egg into a bowl. You may have to shake the contents out a bit. That was cooked and eaten.
I did not want the secondary hole on top if you try the blowing out the egg technique.
The empty egg shells were washed with dish soap and dried.
The egg shells are still fragile so you could slosh the insides with glue or a plaster slurry/slip and let dry.
When dry, you can stuff with a bit of fiberfill. This is all to enhance the light diffusion of the LED inside the egg shell.
Test to see how your lights will look when powered up.
The green LED seems to show off the natural texture of the egg shell the best. Green eggs and ham. Yum!
Step 4: Carbon Dating...
Use a marker to write on the Periodic Table information of the element. I copied the symbol, name, atomic number and atomic weight. You might be able to squeeze in more info depending on your font.
I used a permanent marker but use one with non-toxic ink if you are going to store the eggs and worry about anything migrating through the shell when you eat the eggs.
Light it up and feel those alpha, beta and gamma particles coming at you.
Serve on a Pb plate with graphite chopstick control rods. Wash down with a glass of heavy water.
What's your favorite radioactive element and why? Tell me something below and I might react with scattering a few Pro membership codes your way if your story registers high.