A team of local scientists has developed a technology which allows counterfeit products to be detected by simply breathing on them.
 
The team led by Park Jong-mok in the Korea Research Institute of Chemical Technology developed the technology to produce transparent films that change color with a puff of breath.
 
The technology consists of coating transparent plastic substrates with a newly developed chemical substance in several layers.
 
When exposed to high levels of humidity, the transparent film reacts sensitively and sees a change in the structure of photonic crystals. Such change in structure leads to a change in the color of reflected light. Once the humidity is gone, the film becomes transparent again.
 
The institute said that it is less costly to make the film compared to existing security technologies, including color-changing ink and holograms, given that it can be produced solely by coating high molecular substances and it does not require pigments.