Light-Up LED Lollipops

by dan in Circuits > LEDs

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Light-Up LED Lollipops

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Great fun and yum for every age! Adding a spicy red LED to your lolly is hardly more work than just making regular lollipops. That huge sucker will liven up your halloween party - and keep your guests "licking and sticking" all night long! (because big lollies are super sticky, don't let them drop on the couch)

If you like my projects, I hope you'll check out my new project on Kickstarter

have funs - and yums!

I created this project originally for The Hungry Scientist Handbook

What You Need

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What You Need

A standard recipe for lollipops:
* sugar
* corn syrup
* cream of tartar
* Plastic mold such as a yogurt container
* Sauce pan
* Candy thermometer (can measure up to 300 F)
* Oil or cooking spray
* Measuring cups

Stuff to make an LED go:
* Bic pen
* 2 wires
* 5mm-size LED, any color. make sure it is a "LEAD FREE" or "ROHS" LED.
* 3V coin cell battery

WARNING: if you are in USA it is still legal to sell electronics with lead. you should check that your LED is "LEAD FREE" or "ROHS" before using it in this project. if you are in EU then do not worry, you guys are smart and made it illegal to put lead in the electronics 10 years ago.

Wire Your LED

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  • Cut your wire about 2" longer than your Bic pen.
  • Strip the ends of the wire with a wire stripper.
  • Connect each leg of your LED to a wire. You can just twist them together, you don't need to solder it like I did here.
  • After the wires are securely twisted together, cover the bare part of one of the wires with tape, so that it can't accidentally touch the other.
  • Take apart the pen leaving just the plastic tube
  • insert the wires through the plastic tube until they come out the other end.
  • Touch the two wires to the opposite sides of the battery, and your LED should light up. If it doesn't, flip the battery around and try it the other way.

Make Your Mold

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You need a plastic mold to hold your lollipop liquid until it hardens. The bottom of a yogurt container is convenient, but you can also use some other type of plastic or metal mold. Cut the bottom off your yogurt container with a sharp box cutter, leaving about 1/2" to 1" high walls. Then cut a notch in the side that snugly fits your Bic pen.

Make Lollipop Liquid

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My instructions here are a quick refresher on how to make regular lollipops.  If you have limited kitchen experience and have never made regular lollipops before, check the more detailed instructions about how to make regular lollipops at the link above. 
  • In a sauce pan put: 1/2 cup water, 1/3 cup corn syrup, 1 cup sugar, 1/4 tsp cream of tartar
  • Heat on medium heat and stir until all the sugar dissolves
  • When it starts boiling, you can stop stirring.
  • Add a candy thermometer, and wait until it reaches 300F ("hard crack"). Then immediately remove from the heat.

Get Your Mold Ready and Pour

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Put a thin coating of oil on the inside of your mold

Position your LED and pen in the notch, reaching at least 1/2 inch into the mold.

Once your lollipop liquid cools to 200F you can pour it into the mold, without the plastic melting. If you have any trouble with the plastic melting you can put it into a little ice water like in the photo.

Wait for It to Cool and It's Done!

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Wait for your lollipop to harden

Carefully bend the mold off

Hold your battery between the two wires and wrap them together with tape. That will keep the LED on while you have time to lick it!

WARNING: if you are in USA there may be small amounts of lead on the legs of the LED, in this case do not lick all the way down. if you are in EU do not worry, your electronics are safe to lick!