Wearable user-centric phototherapeutics with bifacial OLEDs for at-home wound healing

Phototherapy is a safe, non-invasive, and effective treatment that can be widely applied to treat various diseases. Conventional LED and laser-based phototherapy have two major drawbacks: (1) they have low uniformity and stability due to local heat and light concentration, and (2) they have spatiotemporal constraints. On the other hand, OLEDs can be treated uniformly with a thin and light surface light source, and it is suitable for wearable and skin-attached platforms due to its excellent expandability and process compatibility. With such characteristics as OLEDs, it is possible to provide users with a comfortable and convenient treatment environment. To overcome the limitation that the existing phototherapy platform simply served as a light source for light therapy, this study proposed a user-friendly OLED phototherapy platform using bifacial OLEDs (Bi-OLEDs) which can be vertical-stacked and parallel-connected. The vertical-stacking process demonstrated a facile fabrication process, and the parallel connection structure ensured individual driving capability, flexibility, driving reliability, and thermal stability. Notably, the red light emitted from OLEDs was observed to enhance wound healing in in vivo tests, achieving 85% wound closure. Therefore, OLED-based phototherapy can be utilized as an innovative platform with both effective light therapy and user interaction.