Researchers develop room-temperature 3D printing technique for ultra-small infrared sensors

A joint research team from the Korea Advanced Institute of Science and Technology (KAIST), Korea University, and The University of Hong Kong has developed a 3D printing-based process capable of producing ultra-small infrared (IR) sensors at room temperature, eliminating the need for conventional high-temperature heat treatment. The breakthrough is expected to contribute to next-generation sensing technologies used in autonomous vehicles, robotics, and Internet of Things (IoT) devices.

Infrared sensors detect light outside the visible spectrum and convert it into electrical signals, enabling object recognition even in dark, smoky, or foggy environments. This capability has earned them the nickname “the eyes of robots.” However, traditional semiconductor-based fabrication requires high-temperature processing, which limits material selection and increases energy and manufacturing costs.

The research team developed a precision 3D nanoprinting process that stacks metallic, semiconducting, and insulating materials in the form of nanocrystal ink. The process allows the IR sensors to be manufactured directly in desired shapes and sizes, including sub-10µm dimensions, approximately one-tenth the width of a human hair.

To maintain high electrical performance without heat treatment, the researchers employed a ligand exchange technique, replacing insulating surface molecules on the nanocrystals with conductive ones. This allowed the printed layers to achieve strong electronic connectivity at room temperature.

Professor Jitae Kim of KAIST stated: “This technology significantly reduces energy consumption associated with high-temperature semiconductor processing. It paves the way for cost-effective and environmentally sustainable sensor manufacturing.”

The research findings were published in the October 16 online edition of the international journal Nature Communications.