< (From left) Professor Dong-Yeun Koh from KAIST, Professor T. Alan Hatton from MIT, Dr. Young Hun Lee from MIT, Dr. Hwajoo Joo from MIT, Dr. Jung Hun Lee from MIT >
Direct Air Capture (DAC) is a technology that filters out carbon dioxide present in the atmosphere at extremely low concentrations (below 400 ppm). The KAIST research team has now succeeded in capturing over 95% high-purity carbon dioxide using only low power at the level of smartphone charging voltage (3V), without hot steam or complex facilities. While high energy cost has been the biggest obstacle for conventional DAC technologies, this study is regarded as a breakthrough demonstrating real commercialization potential. Overseas patent applications have already been filed, and because it can be easily linked with renewable energy such as solar and wind power, the technology is being highlighted as a "game changer" for accelerating the transition to carbon-neutral processes.
KAIST (President Kwang Hyung Lee) announced on the 25th of August that Professor Dong-Yeun Koh's research team from the Department of Chemical and Biomolecular Engineering, in collaboration with Professor T. Alan Hatton's group at MIT's Department of Chemical Engineering, has developed the world's first ultra-efficient e-DAC (Electrified Direct Air Capture) technology based on conductive silver nanofibers.
Conventional DAC processes required high-temperature steam (over 100℃) in the regeneration stage, where absorbed or adsorbed carbon dioxide is separated again. This process consumes about 70% of the total energy, making energy efficiency crucial, and requires complex heat-exchange systems, which makes cost reduction difficult. The joint research team, led by KAIST, solved this problem with "fibers that heat themselves electrically," adopting Joule heating, a method that generates heat by directly passing electricity through fibers, similar to an electric blanket. By heating only where needed without an external heat source, energy loss was drastically reduced.
This technology can rapidly heat fibers to 110℃ within 80 seconds with only 3V—the energy level of smartphone charging. This shortens adsorption–desorption cycles dramatically even in low-power environments, while reducing unnecessary heat loss by about 20% compared to existing technologies.
The core of this research was not just making conductive fibers, but realizing a "breathable conductive coating" that achieves both "electrical conductivity" and "gas diffusion."
The team uniformly coated porous fiber surfaces with a composite of silver nanowires and nanoparticles, forming a layer about 3 micrometers (µm) thick—much thinner than a human hair. This "3D continuous porous structure" allowed excellent electrical conductivity while securing pathways for CO₂ molecules to move smoothly into the fibers, enabling uniform, rapid heating and efficient CO₂ capture simultaneously.
< Figure 1. Fabrication process of the silver nanocomposite-based conductive fibrous DAC device and schematic of CO₂ capture-regeneration mechanism through a rapid operating cycle: (1-1) A porous fiber precursor based on Y-zeolite and cellulose acetate was dip-coated with a silver nanoparticle/nanowire composite and treated with EDA vapor, resulting in an adsorptive fiber with enhanced gas selectivity and conductivity. (1-2) This fibrous DAC system enables stable and efficient CO₂ capture-regeneration even under low-power conditions, through a rapid cycle (e-TVSA) consisting of (i) CO₂ adsorption from air, (ii) gas displacement, (iii) electrically-driven Joule heating, and (iv) cooling and preparation for re-adsorption. >
Furthermore, when multiple fibers were modularized and connected in parallel, the total resistance dropped below 1 ohm (Ω), proving scalability to large-scale systems. The team succeeded in recovering over 95% high-purity CO₂ under real atmospheric conditions.
This achievement was the result of five years of in-depth research since 2020. Remarkably, in late 2022, long before the paper's publication, the core technology had already been filed for PCT and domestic/international patents (WO2023068651A1, countries entered: US, EP, JP, AU, CN), securing foundational intellectual property rights. This indicates that the technology is not only highly advanced but also developed with practical commercialization in mind beyond the laboratory level.
The biggest innovation of this technology is that it runs solely on electricity, making it very easy to integrate with renewable energy sources such as solar and wind. It perfectly matches the needs of global companies that have declared RE100 and seek carbon-neutral process transitions.
Professor Dong-Yeun Koh of KAIST said, "Direct Air Capture (DAC) is not just a technology for reducing carbon dioxide emissions, but a key means of achieving 'negative emissions' by purifying the air itself. The conductive fiber-based DAC technology we developed can be applied not only to industrial sites but also to urban systems, significantly contributing to Korea's leap as a leading nation in future DAC technologies."
< Figure 2. Uniform coating of conductive fibers and characteristics of rapid electrical heating: (2-1) By forming a uniform coating layer, the fiber's resistance was drastically reduced to about 0.5 Ω/cm. (2-2) Heat-transfer simulations analyzing thermal efficiency according to the number of fibers loaded in a module showed that when 12 fibers were used, heat loss was minimized and the most ideal temperature distribution was obtained. This suggests the optimal fiber configuration condition for achieving uniform heating while reducing power consumption. (2-3) In actual experiments, rapid and efficient electrical heating characteristics were observed, with the fiber surface reaching 110 °C within 80 seconds using only 3V of applied voltage. >
This study was led by Young Hun Lee (PhD, 2023 graduate of KAIST; currently at MIT Department of Chemical Engineering) and co-first-authored by Jung Hun Lee and Hwajoo Joo (MIT, Department of Chemical Engineering). The results were published online on August 1, 2025, in Advanced Materials, one of the world's leading journals in materials science, and in recognition of its excellence, the work was also selected for the Front Inside Cover.
※ Paper title: "Design of Electrified Fiber Sorbents for Direct Air Capture with Electrically-Driven Temperature Vacuum Swing Adsorption"
※ DOI: https://doi.org/10.1002/adma.202504542
This study was supported by the Aramco–KAIST CO₂ Research Center and the National Research Foundation of Korea with funding from the Ministry of Science and ICT (No. RS-2023-00259416, DACU Source Technology Development Project).
