A technology has been developed to 3D-print ultra-small infrared sensors in any desired shape and size at room temperature.
Infrared sensors convert invisible infrared light into electrical signals and are core components that recognize objects in robot vision, Autonomous Driving cars' LiDAR, smartphone 3D facial recognition, and wearable healthcare devices. The smaller, lighter, and more varied in shape the sensors are, the higher the performance and versatility of electronic devices.
Until now, infrared sensors have been made through semiconductor processes. While suitable for mass production, they have limits in responding to rapidly changing technology demand, require high-temperature processing that restricts material choices, and consume a lot of energy.
A team led by Mechanical Engineering Professor Kim Ji-tae at the Korea Advanced Institute of Science and Technology (KAIST), together with Professor Oh Seung-ju at Korea University and Professor Tianshuo ZHAO at the University of Hong Kong, said on the 3rd that they developed a 3D printing technology that can fabricate ultra-small infrared sensors under 10 micrometers (µm) in any shape and size at room temperature.
The team applied a high-precision 3D printing technology that stacks metals, semiconductors, and insulators layer by layer using liquid inks of nanocrystals. They added a "ligand exchange" technique. This method replaces insulating molecules that surround nanoparticle surfaces with conductive molecules, improving electrical performance without high-temperature annealing.
As a result, they succeeded in fabricating ultra-small infrared sensors under 10 micrometers—about one-tenth the thickness of a human hair.
Kim said, "This technology goes beyond miniaturization and weight reduction of sensors to enable the development of products in diverse shapes that were hard to imagine before," adding, "By eliminating high-temperature processing, it reduces energy consumption and production expense and even achieves eco-friendly manufacturing, offering high industrial utility."
The findings were published on the 16th in the international journal Nature Communications.
References
Nat Commun(2025), DOI: https://doi.org/10.1038/s41467-025-64596-4