[LAB Exploration] Ajou University Research Team Develops New Technology to Generate Electricity Using Daily Temperature Fluctuations

A research team at Ajou University has developed a technology that collects moisture from the air by utilizing daily temperature fluctuations and converts it into electrical energy.

From the top left clockwise: Taekwang Yoon, Professor at Ajou University; Dongyeon Kim, Researcher at KAIST; Giro Yoon, PhD at Saenggiwon; Yonggyun Lee, Researcher at Ajou University; Jihyun Lee, Researcher at Hanyang University. Ajou University

On July 11, Ajou University announced that a joint research team led by Taekwang Yoon, Professor in the Department of Applied Chemistry and Biological Engineering at Ajou University, and Giro Yoon, Principal Researcher at the Korea Institute of Industrial Technology, has developed a novel energy harvesting system capable of autonomously generating electricity without external water supply, even in extreme environments such as remote areas or deserts with water scarcity.

Energy harvesting is a technology that collects natural energy sources?such as sunlight, vibrations, heat, wind, and waves?or energy wasted in daily life and regenerates it into electrical energy. Conventional water-based energy harvesting technologies generated electricity by utilizing the potential difference between a wet side and a dry side, but they were limited by the need for a constant external water supply. To overcome this limitation, the research team combined two types of metal-organic frameworks (MOFs)?UiO-66-NH2 and Ni3(HITP)2?drawing inspiration from plant transpiration and capillary action. This enabled the realization of a fully autonomous system that collects moisture from the atmosphere and generates electricity independently.

UiO-66-NH2 absorbs moisture from the cool night air and releases the absorbed moisture during the hot daytime. The released moisture condenses on the surface of fibers grown with Ni3(HITP)2, and the asymmetric wetting of the fibers at this stage creates a potential difference, causing electricity to flow. Through this process, the research team succeeded in achieving a maximum power density of 2.6μW/cm3 and an energy density of 1.1mJ/cm3.

In particular, UiO-66-NH2 demonstrated excellent moisture absorption and desorption performance not only in general environments but also in low-humidity conditions, opening up the possibility of application in various environments. The researchers also verified through experiments simulating actual climate conditions?such as deserts, coastal areas, and inland regions?that the system’s self-moisture generation and electricity production functions operate reliably in each environment.

The results of this research were published in the internationally renowned journal 'Composites Part B: Engineering.' The first authors are Jihyun Lee (Integrated Master's and PhD Program at Hanyang University), Dongyeon Kim (PhD Program at KAIST), and Yonggyun Lee (Master's Program at Ajou University). Professor Yoon and Principal Researcher Yoon participated as co-corresponding authors.

Professor Yoon stated, "This study demonstrates the feasibility of a self-sustaining energy harvesting system that can operate without external power or water supply," adding, "We hope it will become a new alternative in disaster sites or regions with limited access to energy in the future."

Principal Researcher Yoon commented, "We have established a technological foundation that allows easy access to electricity even in regions with extreme climates or lacking infrastructure," and added, "We hope this will lead to a substantial contribution to sustainable energy technologies for a carbon-neutral society."