A domestic research team has developed a nanotransfer technology that can move and attach ultrathin metal circuits floating on water to various surfaces. It can be applied not only to sensitive surfaces such as plant leaves and fruit, but also to automobile curves and robot surfaces.
Chair professor Park In-gyu's team in the Department of Mechanical Engineering at KAIST said on the 15th that, in collaboration with principal researcher Chung Joon-ho's team at the Korea Institute of Machinery & Materials (KIMM) and professor Ahn Jun-sung's team at Korea University, they developed a "water-surface floating nanotransfer printing" technology. The findings were published online in Nature Communications in March.
Conventional nanotransfer printing technology is used to move microelectronic circuits to other surfaces, but often requires high heat and pressure, adhesives, or chemical solvents. Because of this, it has been difficult to apply to surfaces sensitive to damage, such as biological tissue, plants, and complex curves.
The team developed a method of floating a metal thin film on water and then transferring it to the desired object. After thinly depositing metals such as gold, platinum, palladium, and nickel on a polymer mold and removing some structures, a metal thin film about 20 nm (nanometers, one-billionth of a meter) thick rises to the water surface while maintaining its original shape.
The transfer is done by submerging the object below the water surface and then slowly lifting it. Capillary forces generated as the water dries press the circuit onto the surface, and it is then fixed without adhesives by intermolecular forces. The team also transferred circuits to hydrophobic surfaces like lotus leaves that repel water well by adding a small amount of ethanol to lower surface tension.
Using this technology, the team fabricated high-sensitivity chemical detection sensors that can be attached to plant leaves and fruit surfaces. On lemon and orange surfaces, they detected thiram, a pesticide ingredient, and by transferring a palladium mesh onto stretchable fibers, they also implemented a wearable hydrogen gas sensor.
Chair professor Park In-gyu said, "This technology is meaningful in that it can transfer nanopatterns even to surfaces where heat or adhesives are difficult to use," and added, "We see potential applications in areas such as smart agriculture, wearable sensors, bioelectronic devices, and robotic electronic skin."
References
Nature Communications (2026), DOI: https://doi.org/10.1038/s41467-026-70902-5