Even after a thousand bends, performance remains uncompromised!

The research team led by Dr. Jongwon Yoon, Dr. Jeongdae Kwon, and Dr. Yonghoon Kim from the Energy & Environmental Materials Research Division at the Korea Institute of Materials Science (KIMS), has successfully developed the world’s first ammonia (NH₃) gas sensor based on a copper bromide (CuBr) film that can be fabricated through a simple solution process at low temperatures. This breakthrough technology not only enables sensor flexibility, ultra-sensitivity, and high selectivity but also significantly reduces manufacturing costs.

Ammonia gas sensors detect airborne ammonia and are utilized in indoor and outdoor environmental monitoring, hazardous gas detection in industrial settings, and disease diagnosis. The copper bromide (CuBr) film used in the sensor exhibits a significant change in electrical resistance upon exposure to ammonia, enabling the detection of even low concentrations of the gas.

In conventional methods, forming the copper bromide (CuBr) film required for the sensor necessitated a high-temperature vacuum process above 500°C. This posed challenges in applying it to flexible substrates, which are vulnerable to heat, and also led to high production costs. To address this issue, the research team developed a technique to form a two-dimensional copper nanosheet on a substrate at a temperature below 150°C without a vacuum process. They then synthesized the copper bromide film through a simple solution-based process. As a result, they successfully implemented an ammonia gas sensor on a plastic substrate.

This study successfully developed a highly sensitive sensor capable of detecting ammonia concentrations as low as one part per million (ppm) using a low-temperature solution-based process. This breakthrough significantly reduces manufacturing costs and offers potential applications in wearable sensors and diagnostic medical devices. Furthermore, experimental tests involving over 1,000 repeated bending cycles confirmed that the sensor maintained high performance and operated with stable functionality.

Dr. Jongwon Yoon, the lead researcher, stated, “The ammonia sensor developed through this study has great potential for expansion into flexible and wearable devices. It can be utilized in a wide range of applications, from indoor air quality monitoring to personal health management.”He further emphasized, “In particular, we expect that it could be applied as a disease diagnosis sensor by attaching it to the human body to analyze exhaled breath.”

The research was conducted in collaboration with Professor Tae-Wook Kim from Jeonbuk National University and Professor Hong Seung Kim from Korea Maritime & Ocean University. This study was supported by the Global TOP Project of the National Research Council of Science & Technology (NST), the Nano and Material Technology Development Program of the National Research Foundation of Korea (NRF), and fundamental projects of the Korea Institute of Materials Science (KIMS). The findings were published online on March 6 in Sensors and Actuators B: Chemical (Impact Factor: 8.0, JCR Top 0.7%), a globally renowned academic journal. The research team is continuing further studies to enhance productivity by developing large-area film-based applications.

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About Korea Institute of Materials Science(KIMS)

KIMS is a non-profit government-funded research institute under the Ministry of Science and ICT of the Republic of Korea. As the only institute specializing in comprehensive materials technologies in Korea, KIMS has contributed to Korean industry by carrying out a wide range of activities related to materials science including R&D, inspection, testing&evaluation, and technology support.