Development of the World's First Broadband Optically Activated Chiral Ceramic Material

Professor Yeom Ji-hyun's Research Team at KAIST Department of Materials Science and Engineering
Applicable in Various Fields such as Biosensors, Imaging, Nano Thermal Therapy, and Communications

Electron microscope image of a material exhibiting broadband optical activity, optical activity graph, and computer simulation results

[Asia Economy Reporter Kim Bong-su] The Korea Advanced Institute of Science and Technology (KAIST) announced on the 30th that it has developed the world's first chiral ceramic material exhibiting optical activity across a wide spectrum from visible light to ultraviolet and even short-wave infrared regions. This achievement is regarded as laying the foundation for the application and advancement of chiral nanomaterials such as biosensors.

Chiral nanomaterials are characterized by optical activity that shows different optical properties depending on the right- or left-handed circular polarization of the incident light. These materials have recently attracted attention due to their unique property of exhibiting different optical characteristics depending on their structure, even if they are made of the same substance, which opens up many potential applications. However, most previously reported chiral nanomaterials have had optical activity limited to the ultraviolet and visible light regions, restricting their applications in various fields including bio and communication technologies.

The research team led by Professor Yeom Ji-hyun from KAIST's Department of Materials Science and Engineering has developed for the first time a chiral material exhibiting broad optical activity extending from the ultraviolet through the near-infrared and into the short-wave infrared regions. The team introduced a technology that systematically imparts chiral characteristics to copper sulfide ceramic materials from the atomic scale up to the micro scale. Simultaneously, they induced a chemical state change in copper sulfide nanoparticles to a phase that effectively absorbs long-wavelength light, maximizing the optical activity efficiency in the infrared region.

First, the team transferred the atomic-level chiral properties of amino acids to inorganic nanoparticles to realize nanoscale chiral characteristics. Then, by controlling the attractive and repulsive forces between nanoparticles, they induced the self-assembly of chiral nanoflowers (NFs) with lengths of 1 to 2 micrometers (㎛). They confirmed that these designed nanoflowers interact distinctively with circularly polarized light from ultraviolet to infrared wavelengths spanning several micrometers. The broadband optical activity was attributed to the chemical transformation into the copper sulfide phase capable of absorbing infrared light as induced by the team, and the structural chiral properties of the nanoflowers causing asymmetric interactions depending on the circular polarization direction, as demonstrated through computational simulations.

This developed broadband optical activity nano platform technology is expected to be applied in various fields such as biosensors, bioimaging, infrared neural stimulation, nano-thermal therapy, and telecommunications.

Park Ki-hyun, a master's student at KAIST and the first author, stated, "We hope to contribute to developing a new paradigm of nanomaterials by creating a chiral material library and utilizing self-assembly control technology. Above all, by developing the world's first material exhibiting optical activity in the short-wave infrared region, we believe we have laid the foundation for the application and advancement of chiral nanomaterials."

The research results were published in the international journal ‘ACS Nano’ issued by the American Chemical Society.

Meanwhile, chiral refers to a term used in various scientific fields such as mathematics, chemistry, physics, and biology to describe asymmetry. For example, chirality exists when the shape of an object does not coincide with its mirror image.

This content was produced with the assistance of AI translation services.