(Photo) Schematic diagram of the energy generation system and mechanism:
(a) Autonomous electrical energy harvesting system driven by water circulation due to temperature difference between day and night
(b) Water harvesting mechanism using UiO-66-NH₂
(c) Electrical energy generation mechanism using Ni3(HITP)2
(d) Autonomous water harvesting and sustainable electrical energy generation system under ambient environmental conditions

A Korean research team has developed a technology that collects moisture from the air using temperature differences between day and night, and converts it into electrical energy.

The joint research team, led by Professor Taekwang Yoon from the Department of Applied Chemistry and Biological Engineering at Ajou University and Principal Researcher Giro Yoon from the Korea Institute of Industrial Technology (KITECH), has introduced an innovative energy harvesting system. This system is capable of generating electricity independently without any external water supply, even in extreme environments such as remote areas or deserts where water is scarce.

The results of this research were published in the internationally renowned journal Composites Part B: Engineering (top 1% in JCR), under the title:
"Sustainable electrical energy harvesting via atmospheric water collection using dual-MOF systems."

The first authors of the study are Ji-Hyun Lee (integrated master’s and Ph.D. program, Hanyang University), Dong-Yeon Kim (Ph.D. candidate, KAIST), and Yong-Gyun Lee (master’s student, Ajou University).
Professor Taekwang Yoon and Principal Researcher Giro Yoon served as co-corresponding authors.

Traditional water-based energy harvesting technologies rely on the potential difference between wet and dry surfaces to generate electricity, but they have the limitation of requiring a constant external water supply. To overcome this, the research team was inspired by plant transpiration and capillary action, and combined two types of metal-organic frameworks (MOFs)—UiO-66-NH₂ and Ni₃(HITP)₂.
As a result, they successfully developed a fully autonomous system that collects moisture from the air and generates electricity on its own.

UiO-66-NH₂ absorbs moisture from the cool night air and releases the absorbed moisture during the warmer daytime. The released moisture condenses on the surface of fibers coated with Ni₃(HITP)₂. This condensation causes asymmetric wetting on the fiber surface, generating a potential difference, which allows electricity to flow. Through this process, the research team successfully achieved a maximum power density of 2.6 μW/cm³ and an energy density of 1.1 mJ/cm³.

Notably, UiO-66-NH₂ exhibited excellent moisture adsorption and desorption performance, not only under normal conditions but also in low-humidity environments, showing its potential for use in various settings. The team conducted experiments simulating real climate conditions—including desert, coastal, and inland environments—and confirmed that the system could stably generate moisture and electricity autonomously across all tested scenarios.

Professor Taekwang Yoon stated:

“This research demonstrates the feasibility of a self-sustaining energy harvesting system that can operate without any external power or water supply.
We hope it serves as a viable solution in disaster zones or areas with limited access to electricity.”

Principal Researcher Giro Yoon added:

“This system provides a technological foundation for easy electricity generation, even in extreme climates or regions lacking infrastructure.
We expect this to make a meaningful contribution to sustainable energy technologies for a carbon-neutral society.”

This research was supported by the National Research Foundation of Korea under the Global Research Infrastructure Cooperation Hub Program.

[Energy Harvesting] refers to the technology of collecting energy from natural sources—such as sunlight, vibrations, heat, wind, waves, or even waste energy from daily life—and converting it into usable electrical energy.

From the back row, starting from the left : Professor Taekwang Yoon (Ajou University), Researcher Dongyeon Kim (KAIST), Principal Researcher Giro Yoon (KITECH), 

Researcher Yonggyun Lee (Ajou University), and Researcher Jihyun Lee (Hanyang University)