OLEDs are considered to be particularly suitable for wearable devices or human touchable devices. They can be processed on various flexible substrates at low temperature, such as plastics, which is very useful for realizing light sources as light as goose feather, flexible, stretchable and conformal objects. In fact, most of the display devices used by wearable devices such as smart watches is plastic active matrix OLED because of its lightweight and thin appearance. OLEDs applications in wearable devices are not limited to smart watches. In fact, OLEDs also play an important role in the field of mobile medicine, and its form of wearable devices is particularly popular