Becky Stern is back at it again with another amazing project. Inspired by her love of Ariel, the princess from Disney’s The Little Mermaid, she has made a sparkly contribution to the world of wearable tech. This gorgeous glowing hair accessory is made using an RP2040-powered microcontroller board, LEDs, and mermaid magic.

I can’t help but think about how much I would have loved this mermaid hair design back when I was twelve years old, performing in my school’s rendition of The Little Mermaid [I would wear this now — Ed]. Although I played the evil villain, Ursula the sea witch, who is most definitely not a mermaid, I would still have loved to wow the audience with my light-up LED hair on stage. Sea witches deserve pretty hair too.

This hair accessory would also be perfect for fancy evening dos — imagine this paired with Angelina Tsuboi’s glowing LED prom dress that I wrote about in my last blog post! You would certainly outshine everyone at the ball.

Hardware

• Tiny wire strips with LEDs
• Seeed XIAO RP2040 microcontroller board
• 1-metre USB cable
• USB power bank
• 3D printed shells
• A human who is good at doing hair

How it works

Becky carefully sandpapered the protective coating on the LED wires so that she could solder the lights directly to the Seeed microcontroller. This microcontroller is what’s running the code to control the colours shown on each individually addressable LED.

Becky’s friend, hair and makeup artist Hinano Leung, helped her with the finishing touches. She curled Becky’s hair into beachy waves and added some fish scale-inspired makeup to her cheeks for extra mermaid glamour. Becky tweaked the rainbow function code to use only part of the colour wheel for each hair piece, so that each mermaid had her own theme — blues and greens for Hinano’s, and reds and pinks for Becky’s. This code is available to copy from DigiKey’s project post.

3D printed seashell-shaped diffusers were hot-glued to the LEDs and interspersed with nautically themed hair clips on each wearer’s head. The RP2040 board is hidden behind some hair at the nape of the neck, with the power cable for the USB battery pack snaking down inside the wearer’s shirt.

Why not make this yourself?

Watch Becky’s YouTube video and check out her Instructables post for all the details on how she made this magical hair accessory. You’ll find the code, the 3D seashell design, and more lovely photos of the process.