Growing LED Butterflies Built with JLCPCB's Transparent FPCs

What if a butterfly could flutter with light? No wires, bulk, and complex control, just motion and glow. That's exactly what this glowing FPC-based creation achieves! Built with JLCPCB's 2-layer transparent FPC, this elegant LED butterfly is lightweight, low-power, and visually striking, showing how seamlessly advanced electronics can blend with creative aesthetics.

Let’s take a closer look at how this idea took flight and how JLCPCB's services made it all possible.

Project Introduction

This artistic electronic decoration combines circuit engineering with visual design. The butterfly's wings are made of 2-layer tranparent FPCs with ultra-low-power LED circuits, that uses a self-oscillating design requiring no microcontroller or programming.

In order to create a rhythmic lighting effect that resembles the fluttering of butterfly wings, two symmetrical circuit blocks alternately trigger the left and right LED groups to flash. Each circuit block includes a resistor R1, a resistor R2, a capacitor C, a transistor (BC547 or S8050), and LEDs.

The capacitor (C) charges slowly through resistor R1. Once the voltage across the capacitor exceeds the transistor's turn-on threshold (approximately Vbe + Vf), the transistor switches on, allowing the capacitor to discharge rapidly. Then this discharge current drives the LEDs, causing them to light up. After the discharge, the capacitor voltage drops sharply, turning off the transistor and extinguishing the LEDs. At the same time, the opposite side of the circuit begins its charging phase, repeating the cycle and creating an alternating flashing effect.

Project BOM

How JLCPCB Made It Both Possible and Beautiful

Thanks to JLCPCB's transparent FPC service, the designer could go beyond aesthetics and embed real electronic functionality directly into the wings, resulting in a seamless fusion of form and function. JLCPCB provides lightweight and transparent 2-layer flexible PCBs, which are ideal for hanging displays or wearable accessories, enabling the lightness and transparency of butterfly wings.

Advantages of JLCPCB Transparent FPCs

● High Optical Transparency: With up to 85% light transmittance, the FPC allows the circuit itself to become part of the visual design, perfect for lighting effects such as the fluttering LED wings used in the butterfly.

● Dual-Sided SMT Support: JLCPCB fully supports mounting LEDs on both sides of the 2-layer transparent FPC, with through-hole alignment. Wiring can be routed on one side while decorative patterns are printed on the other side.

● Cost-Efficient & Fast Prototyping: JLCPCB offers 30–50% lower pricing than typical market transparent FPC options, making it practical for both creative and functional prototypes.

Right now, new users can get $10 off transparent FPC orders. It's an ideal chance to bring your artistic or wearable electronics ideas to life.

Conclusion

From idea to illumination, this glowing butterfly shows how flexible electronics can support elegant, power-efficient designs. With the help of JLCPCB's flexible PCB services, even delicate art-inspired concepts can take flight—literally.