South Korean, Hong Kong Universities Developing Hat-Like Wearable to Prevent Hair Loss

Future hair loss prevention could be as simple as putting on a hat.

A joint research team in South Korea has developed a hat-like, wearable organic light-emitting diode (OLED)-based phototherapy device and demonstrated it can suppress hair-follicle cell aging by up to 92%, a key factor in hair-loss progression. The research team, led by Professor Kyung Cheol Choi of the KAIST School of Electrical Engineering (South Korea), in collaboration with Professor Yun Chi’s group at the Hong Kong University of Science and Technology, developed the non-invasive hair-loss treatment technology using a textile-like, flexible wearable platform integrated with specially designed OLED light sources.

Drug-based treatments for hair loss are effective, but concerns about long-term side effects have driven interest in safer alternatives such as phototherapy. However, existing phototherapy devices for hair loss are typically bulky, rigid helmet-type systems, limiting their use to indoor environments. Moreover, because they rely on point light sources such as LEDs or lasers, it has been difficult to deliver uniform light irradiation across the entire scalp.

To address these challenges, the researchers replaced point light sources with area-emitting OLEDs, which emit light uniformly over a wide surface. In particular, they integrated near-infrared (NIR) OLEDs into a soft, fabric-like material that can be worn as a cap. This design allows the light source to naturally conform to the contours of the scalp, delivering even optical stimulation over the entire scalp.

“Because OLEDs are thin and flexible, they can closely conform to the curved surface of the scalp, delivering uniform light stimulation across the entire area,” Choi said. “Going forward, we plan to verify safety and efficacy through preclinical studies and progressively evaluate the potential for real therapeutic applications.”

Beyond wearable design, the study focused on suppressing hair-follicle cell aging, a central driver of hair-loss progression. The key achievement of this work lies not only in realizing a wearable device but also in precisely tailoring the wavelength of light to maximize therapeutic efficacy.

Recognizing that cellular responses vary depending on light wavelength, the team extended wavelength-control techniques originally developed for display OLEDs to therapeutic applications. Thus, they fabricated customized OLEDs that selectively emit near-infrared light in the 730 nm to 740 nm range, which is optimal for activating critical dermal papilla cells located at the base of hair follicles that regulate hair growth.

The researchers validated the NIR OLEDs’ efficacy through experiments using human dermal papilla cells (hDPCs). Cellular aging analysis showed that NIR OLED irradiation suppressed cell aging by roughly 92% compared with the control group, outperforming conventional red-light irradiation conditions.

“Instead of rigid, helmet-type point-light devices, we propose a wearable phototherapy platform that can be used in daily life by implementing soft, textile-based OLEDs in a cap form. A key outcome of this study is demonstrating that precisely engineered light wavelengths can effectively suppress hair-follicle cell aging,” first author Dr. Eun Hae Cho commented.

This research was led by Dr. Cho of the KAIST School of Electrical Engineering and was published online earlier this year in Nature Communications. The paper title is: “Wearable Textile-Based Phototherapy Platform With Customized NIR OLEDs Toward Non-Invasive Hair Loss Treatment.”

The research was conducted with the support of the Ministry of Science and ICT through the National Research Foundation of Korea (NRF) under the National R&D Program (Future-Oriented R&D Convergence Science and Technology Development Program (Bridge Convergence Research): Development of a skin patch for wound treatment integrating bio-tissue adhesive patches with drug delivery and phototherapy OLED therapy, the Technology Innovation Program supported by the Ministry of Trade, Industry and Energy (development of substrate materials stretchable by more than 50% for stretchable displays), and the BK21 FOUR Program of the Ministry of Science and ICT (Connected AI Education & Research Program for Industry and Society Innovation, School of Electrical Engineering, KAIST).