A research team has created wearable displays for various applications including healthcare. Integrating organic light-emitting diodes (OLEDs) into fabrics, the team developed highly flexible and reliable technology for wearable displays. The team used two different approaches, fabric-type and fiber-type, in order to create the clothing-shaped wearable displays.

OLEDs operating in fabric.
(Credit: KAIST)

In 2015, the team successfully laminated a thin planarization sheet thermally onto fabric to form a surface that is compatible with the OLEDs, approximately 200 nm thick and reported their outcomes on enhancing the reliability of operating fiber-based OLEDs. In 2016, they introduced a dip-coating method capable of uniformly depositing layers to develop polymer light-emitting diodes, which show high luminance even on thin fabric. Based on the earlier research, the fabric-based OLEDs showed high luminance and efficiency while maintaining the flexibility of the fabric.

The long-term reliability was verified through organic and inorganic encapsulation technology. According to the team, their wearable device facilitates the operation of OLEDs even at a bending radius of 2 mm. Having wavy structures and empty spaces, fiber plays a significant role in lowering the mechanical stress on the OLEDs.