Korea Advanced Institute of Science and Technology (KAIST) said on the 8th that a joint research team led by Kim Il-doo, a professor in the Department of Materials Science and Engineering, and Lee Seung-seop, a professor in the Department of Mechanical Engineering, developed a technology that can remove ultrafine dust almost perfectly without a filter by using nano-sized droplets.
The device combines Professor Lee Seung-seop's "ozone-free water electrospray" technology and Professor Kim Il-doo's "hygroscopic nanofiber" technology. Inside the device are a high-voltage electrode, a nanofiber absorber that wicks water on its own, and polymer microchannels that move water via capillary action. Thanks to this structure, a self-pumped configuration is achieved in which water is automatically supplied without a pump, enabling long-duration, stable water electrospraying.
In tests conducted by the research team in a 0.1 m³ experimental chamber, the device removed 99.9% of various particles in the PM0.3–10 range within 20 minutes. In particular, it showed excellent performance by removing 97% of PM0.3 ultrafine particles—difficult to eliminate with conventional filter-type air purifiers—within 5 minutes. It can quickly remove even ultrafine particles as small as PM0.3 (diameter 0.3 μm) and below, which are about one-200th the thickness of a human hair.
It operated stably without performance degradation in 30 consecutive tests and during 50 hours of continuous operation.
The technology is currently being commercialized through A2US, a startup from Professor Lee Seung-seop's laboratory and a recipient of a CES 2025 Innovation Award. The goal is to launch a product next year. The research findings were published on the 14th of last month in Advanced Functional Materials, an international journal from Wiley recognized as authoritative in materials science and nanotechnology.