Tiny LED Earrings are a Miniaturization Tour de Force

Light up jewelry is nothing new – we see wearables all the time here. But home brew, self-contained, programmable LED earrings that are barely larger than the watch batteries which power them? That’s something worth looking into.

assembly5Settle back and watch [mitxela]’s miniature wizardry in the video below, but be forewarned: it runs 36 minutes. Most of the video is necessarily shot through a microscope where giant fingers come perilously close to soldering iron and razor blade.

The heart of the project is an ATtiny9, a six-legged flea of a chip. The flexible PCB is fabricated from Pyralux, which is essentially copper-clad Kapton tape. [Mitxela] etched the board after removing spray-paint resist with a laser engraver – an interesting process in its own right.

After some ridiculously tedious soldering, the whole circuit wraps around a CR927 battery and goes into a custom aluminum and polypropylene case, which required some delicate turning. Hung from off-the-shelf ear hooks, the 12 multiplexed LEDs flash fetchingly and are sure to attract attention, especially of those who know Morse.

This isn’t exactly [mitxela]’s first tiny rodeo, of course. We’ve featured his work many times, including a Morse code USB keyboardthe world’s smallest MIDI synthesizer, and the world’s smallest MIDI synthesizer again.

Thanks to [vikas] for the tip.

22 thoughts on “Tiny LED Earrings are a Miniaturization Tour de Force

      1. Once I had a very small board (~20*20mm) I used a piece of scrap plywood or acrylic of about 8 to 10cm size and some double sides tape to stick the PCB on it. So I could move it around as necessary, but it had enough weight to stay in place while soldering.

  1. I had a colleague who would take a red LED and a hearing-aid battery, stick the LED leads through his tie (this was back in the Late Bronze Age) and put the battery between the leads, scrupulously observing polarity, and secure the whole thing with a little sleeve of plastic tubing. He’d then put a dozen or so of each component in his pocket, proceed to his favorite watering-hole, and sell luminous tie-pins for $5.00 apiece. He never got rich but then he was never thirsty, either.

  2. Give me a break :-D
    Why even bother with a PCB ?
    Here is an old prototype : http://ygdes.com/bijoux/mantra1.jpg
    missing : the tiny hearing-aid silver battery, overall the electronics (joule thief, µC) + tiny battery is smaller than a 927 Li battery.
    And the pink LED sends a morse message.

    After mastering the art of winding ultra-thin coils, I did an even smaller joule thief : http://ygdes.com/baguette/baguette_dcdc.jpg

    More at http://ygdes.com/bijoux/ and http://ygdes.com/baguette/

    1. These are great! You bothered with a PCB, it was just one that already had the LED mounted on it. :)

      m, I think you’re seeing phosphor on the LED die, excited by ambient light or the camera flash.

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