Candied LEDs Are A Light, Tasty Treat


[Emily Daniels] recently snagged a free iPad in the Instructables “Play with your food challenge” with an interesting way to work with LEDs. Growing up, most kids attempted to make, or at least have seen rock candy be produced. [Emily] thought it would be interesting to mix LEDs with the stuff to see what she could come up with, and her candied LEDs are the result.

The process is pretty straightforward, and involves mixing up a batch of supersaturated sugar syrup in which LEDs are suspended. The LEDs act as a nucleation point for the crystal formation, growing a nice solid coating of sugar after a couple weeks’ time. After some cleaning up, the LEDs can be connected to a coin cell battery or similar, as you would normally do. The sugar acts as a diffusing medium for the LEDs, giving them a nice soft beam pattern.

Obviously you likely wouldn’t want to use these for any long-term electronics project, but it’s a fun activity for the kids, and it could be a good way to incorporate electronics into baked goods.

17 thoughts on “Candied LEDs Are A Light, Tasty Treat

  1. I doubt there would be any ill effects, just don’t chew…

    Just be careful not to use lead alloys for soldering, lead poisoning is not pretty. Maybe she could coat the leads and wires with something inert?

    I guess a small coin cell, two-color LED, NTC and/or PTC could be used to make a small circuit (coated with sugar, if you like) to indicate the temperature of your tea or coffee (hot, drinkable, cold)? Throw in a normally-open reed switch to turn them off with a magnet when not in use, and cover with something like clear epoxy.

    Very creative, and I see some potential! Totally useless, but fun nonetheless.

  2. Normally I’m not a fan of lead free solder and think some people’s phobia of leaded solder is way over the top. In this case however I think lead-free solder actually has a use!

      1. Tin Whiskers

        Toxicity of rosin and subsequent smoke is worse in lead-free

        More heat on components

        Necessity to tin the PCB

        Tin Whiskers!

        And.. having never experienced lead poisoning myself, even after 20 years of exposure to leaded solder And knowing others with 50+ years exposure, still without any problems I really do not see the point.

        I do understand that lead is poisonous. However, I have yet to see anybody make a convincing case that soldering with it gets it into ones body. All the anecdotal evidence I have seen says it does not. Meanwhile plenty have made convincing cases of why lead free is worse.

      2. Lead solder flows much better at a lower temperature than lead-free making it ideal for surface mount and temperature sensitive components (LEDs)

        Lead doesn’t vaporize until ~800*, so unless you’re soldering with a torch, you shouldn’t have a chance of lead poisoning. That is probably why you’re doing fine after many years!

    1. For anyone worried about the LEDs, the “tasty treat” portion of the title was a joke.

      Emily makes it very clear in her writeup that these are for decoration only and should not be eaten.

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