Photonic Crystals Produce Fully Colored Fingerprints

Filed in archive Other Biotechnology News on March 20, 2006

The world, especially the law enforcement officials can now say goodbye to traditional ink fingerprints, thanks to the new technology developed by a University of Toronto-led team of international researchers.

This new technology uses elastic photonic crystals to capture data-rich fingerprints in multiple colors. The paper on this new research is featured on the cover of the journal Nature Materials' current issue. The colored fingerprinting technique is just one application of the technology.

"You can elastically deform these crystals and produce different colours," says lead author André Arsenault, a PhD candidate in the laboratory of Geoffrey Ozin, a University Professor in the Department of Chemistry and a Canada Research Chair in materials chemistry.

Photonic crystals are a relatively new development in the scientific quest to control light. Ozin's lab first created photonic crystals in 2002, using spherical particles of silica mere micrometres in diameter that self-assemble into neat layers, creating what's known as an opal. After filling the space between the spheres with silicon, they used acid etching to remove the silica balls. This left an ordered sponge of air bubbles in silicon known as an inverse opal. This photonic crystal material, the first of its kind, did indeed trap light. These photonic crystals can produce colour based on how an electromagnetic wave interacts with the structure - meaning that it could be tuned to produce any colour.

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