TAIPEI (Taiwan News) — A joint research team from National Yang Ming Chiao Tung University (NYCU) and Germany’s Karlsruhe Institute of Technology has developed a nanochannel technology that mimics algae’s light-sensing ability, providing a novel tool for anti-counterfeiting and smart materials.

The breakthrough replicates phototaxis—the way green algae respond to light—by using a photosensitive polymer embedded in nanochannels to control ion flow, per CNA. The system can switch its behavior when exposed to ultraviolet light, offering a new mechanism for light-controlled functions.

According to NYCU, algae use phototaxis to maximize sunlight exposure for photosynthesis. This movement is regulated by rhodopsins, light-sensitive ion channels in their cell membranes that alter ion flow in response to environmental stimuli.

Led by Professor Chen Chun-tai (陳俊太) of NYCU’s Department of Applied Chemistry, the team used anodized aluminum oxide membranes as a platform and embedded the polymer spiropyran into the nanochannels.

Chen explained that under UV light, spiropyran, a kind of organic chemical compound, changes from a closed-ring structure to an open, charged-ring form. This shift alters the material’s surface properties, affecting how ions pass through the channel and changing the material’s color from transparent to deep purple.

The color change offers a potential security feature for optical anti-counterfeiting labels, enabling instant verification. It could be used in applications such as product authentication, document security, or high-value packaging.