Professor Kyung Cheol Choi and PhD candidate Yongmin Jeon of the School of Electrical Engineering successfully developed an OLED wearable light therapy patch alongside Professor Kyoung-Chan Park and researcher Hye-Ryung Choi of the Seoul National University Bundang Hospital. The research was published in the international journal Advanced Materials Technology on March 8.

Light therapy, or phototherapy, is a type of treatment in which the biochemical reactions of the body are promoted by radiating light on the damaged area. However, the existing equipment is not flexible, has difficulties radiating light uniformly, and it generates large amounts of heat to the point of potentially causing minor burns on patients. Due to these limitations, patients could receive treatment by visiting hospitals with the LEDs and laser devices installed.

However, Professor Choi’s research team has found a way of providing phototherapy “on the go”. The team developed a light therapy patch that can be attached to the skin, providing high-efficiency treatment alongside daily life activities. The patch accommodates the OLED, battery, and heatsink into a thin flexible film that is less than 1 mm in thickness, weighs less than 1 g, and can be bent to a radius of 20 mm. It can also provide light therapy for more than 300 hours. Furthermore, the patch operates at temperatures lower than 42 ºC, meaning that there is no risk of low temperature burns. It has also been approved by the International Standard Organization (ISO). Due to such properties, the patch can easily be attached to various parts of the body to provide treatment for extensive durations of time with little discomfort for the patient.

With regards to its effectiveness, the patch increases cell proliferation — the process of increasing the number of cells — by 58% and cell migration by 46%. This resulted in outstanding healing effects in wounded areas.

Jeon, who led the research, said, “The excellent treatment effect and convenience of the wearable light therapy patch will make it possible for people to receive light therapy by simply purchasing one of the patches from a pharmacy, rather than having to visit the hospital.” He added, “By adjusting the light output, the range of applications can be broadened to include skin cancer, skin beauty, dementia, and depression.”