<p>Organic light emitting diodes (OLEDs) are evolving as nontraditional electronic devices owing to their mechanical flexibility, high visual quality, quick activation speed, and efficiency at low voltages and across wide temperature ranges. OLEDs have become widely used for display and lighting applications; however, they are now being used as sensors light sources, and light detectors for biomedical applications and early detection of disease. Advances in OLED design, architecture, device technology, and synthesis fabrication techniques have allowed for improvements in performance, durability, and utility. The article describes the various OLED design architectures, the individual layer function, and the individual layer materials responsible for charge conduction, exciton formation, and light emission. In addition, advances in fabrication processes, efficiency improvements, and life extensions of OLEDs have been identified, with consideration of future applications of OLEDs in organic thin film transistors, integrated optical sensors, and medical devices. Taken together, these perspectives present the current status of OLED devices, materials, and engineering techniques as well as future developments for OLEDs.</p>