A research team from Ajou University has proposed a method to mass-produce high-purity metal nanoparticles through a light-assisted nanomaterial synthesis technique. This breakthrough is expected to be widely applicable in next-generation artificial sensory systems and neuromorphic devices that mimic the human brain, where precise sensing capabilities are essential.

Led by Professor Sungjun Park from the Department of Electrical and Computer Engineering and the Department of Intelligent Semiconductor Engineering, the team introduced a novel strategy for producing high-purity metal nanoparticles without chemical reactions, using a light-based laser ablation in liquid (LAL) technique. This approach allows for the synthesis of nanoparticles free of organic residues on a large scale.

The research findings were published in July in a review article titled “Scalable metal-based nanoparticle synthesis via laser ablation in liquids for transformative sensory and synaptic devices” in the prestigious journal International Journal of Extreme Manufacturing (Impact Factor 21.3, top 0.7% in JCR in manufacturing and process engineering).

The study was led by Dr. Junkyu Choi from Ajou University’s Institute of Information & Electronics Research, with Sukhyeon Baek, a Ph.D. student in the Department of Intelligent Semiconductor Engineering, as a co-author. Junghoon Lee, a Ph.D. candidate in the same department and currently working at Samsung Electronics DS Division's Materials Technology Team, also participated as a co-corresponding author, along with Professor Sungjun Park.

Artificial sensory systems are technologies that mimic the human five senses, converting external stimuli into electrical signals. These technologies are rapidly gaining attention as essential components in various fields, including: the metaverse, extended reality (XR), wearable medical devices, human-machine interfaces. There is increasing demand for applying lighter and more flexible materials, instead of bulky hardware, to real-life applications. As a result, research into next-generation artificial sensory systems is accelerating.

In such devices, metal nanoparticles play a crucial role in maximizing sensor performance, thanks to their tunable electrical, optical, and chemical properties. In sensory applications, they enhance sensitivity and response speed to external stimuli while maintaining high selectivity and stability in complex signal environments.

In neuromorphic devices, metal nanoparticles enable precise control of synaptic responses and plasticity, serving as key components in implementing biomimetic learning functions. These properties greatly contribute to improving the precision and efficiency of next-generation artificial sensory systems.

However, conventional nanoparticle synthesis methods rely on physical techniques requiring high-temperature vacuum equipment, or wet-chemical reactions using surfactants and reducing agents.

These approaches involve complex processes and often leave organic residues on the particles, which can degrade electrical properties and reduce sensor reliability. Moreover, they face significant limitations in large-area fabrication and mass production, posing challenges for commercialization.

To address these issues, the Ajou University team focused on "Laser Ablation in Liquids (LAL)", a non-contact, physical-based synthesis method that enables the production of high-purity metal nanoparticles without chemical reactions. Unlike traditional physical deposition methods that yield only a few hundred milligrams per hour, the proposed LAL technology can achieve production rates of over 8 grams per hour, significantly boosting its potential for real-world industrial applications.

Laser ablation in liquids process (left) and actual formation of nanoparticles (right)

The review paper also holds significant value in that it expands the application potential of Laser Ablation in Liquids (LAL)-based metal nanoparticles beyond their conventional use in catalysis and electrochemistry, extending it to the broader field of the electronics industry. In particular, the study demonstrates that applying high-purity nanoparticles synthesized via LAL to next-generation artificial sensory systems—such as electronic skin (e-skin), neuromorphic devices, and wearable electronics, where precise detection of external stimuli is critical—enables both long-term stability and high sensitivity.This work clearly highlights the potential for expansion into various smart electronic applications, including: human–machine interaction, AI-based robotics, medical monitoring technologies. Through this, the research offers a new direction for the electronics industry as a whole.

Professor Sungjun Park stated, “This achievement goes beyond introducing a new technique—it represents a turning point for ‘light-based nanomanufacturing technologies’ that could drive the commercialization of next-generation smart sensors and neuromorphic systems. It marks a major milestone for the materials and sensor industries, both domestically and internationally.”

He further emphasized, “To realize commercial applications, follow-up studies on long-term storage stability and synthesis optimization of LAL-based metal nanoparticles are essential. A strategic roadmap is needed to bridge foundational nanotechnology and real-world industrial deployment.”

This research was supported by the National Research Foundation of Korea (NRF) through the Nano·Materials Technology Development Program, including the Global Young Connect Project and the Nano Future Materials Core Technology Development Project.