The bandage cover of Leaf-band-aid is made of a special colour-changing material, which gradually changes as it senses and begins to react to the temperature of the human skin. When a Leaf-band-aid is used for more than three days, it changes into a colour that indicates it is ‘perishing’ to remind the user to change the band-aid. It is common for people to forget about changing their band-aids. According to medical studies, when band-aids are used for a long time, bacteria tend to grow which leads to an infection and inflammation of the wound. In severe cases, the wound becomes ulcerous and ischemic necrosis occurs. Doctors usually suggest that band-aids be changed every three days to avoid such risks. In the past, people would pick leaves and use them to accelerate the healing process of the wounds (by making use of the chlorophyll in the leaves). The design of Leaf-band-aid continues such a traditional remedial concept, while building user awareness towards the right and safe way to use band-aids.