Phototherapy Flex Cap

Flex PCB cap for red and NIR light therapy using multiplexed LED control.

Designed a flex PCB in Altium Designer for red and NIR light therapy aimed at hair regrowth. The goal is to deliver consistent, low-level light to the scalp, a technique often described as photobiomodulation. The layout uses dense 0603 red and NIR LEDs arranged for even coverage, with multiplexing that cycles power between LED groups so the overall dose stays uniform while heat and current are kept manageable. Two level shifters coordinate the timing signals that drive those LED groups.

The current prototype uses an external MCU and through-hole wiring to drive the cap, which makes the mechanical connections fragile. A future revision should integrate the MCU directly on the flex, reinforce the interconnects, and replace through-hole wiring with soldered pads or strain-relieved connectors for better durability and control.