Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pressable photonic crystals produce full-colour fingerprints and promise enhanced security

15.03.2006


Experiment reveals layers of data missed by traditional ink fingerprints

In the future, law enforcement officials may take full-colour fingerprints using new technology developed by a University of Toronto-led team of international researchers.

Far from the basic black-and-white fingerprints collected today, the new technology would use elastic photonic crystals to capture data-rich fingerprints in multiple colours, but the fingerprinting technique is just one potential application for the new technology. A paper on the new research is featured on the cover of the current issue of the journal Nature Materials.



"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.

In the new study, the team injected an elastic compound between the spheres, which were then etched away, leaving an orderly and compressible elastic foam that can be transferred onto virtually any surface, such as glass, metal or plastic. The material changes colour based on how far the spheres are separated.

"The material we have is very, very thin," Arsenault says. "We can coat it onto any surface we want." If the foam is compressed, it alters the lattice dimensions, changing the wavelength of light that it produces. The team demonstrated the fingerprint application, using Arsenault’s finger, and produced both still images and a video of the process, which captures detailed information about pressure patterns and surface ridges that may not be visible to the naked eye.

Taking it one step further, Arsenault made a rubber replica of his fingertip, which might fool a traditional fingerprint scan. "If you press the rubber replica into the material, the pressure impressions that you get are very different," he says. "The lines are much sharper, because the material is less soft. From the standpoint of biometrics, this could provide better security."

Arsenault says the technology could be used not only for colour fingerprints, but in sensors for air-bag release mechanisms in cars, strain and torque sensors on support beams of high-rise buildings and in laser sources. The study was funded by the Natural Sciences and Engineering Research Council of Canada, the University of Toronto, EC NoE Phoremost and Deutsche Forschungsgemeinschaft.

Nicolle Wahl | EurekAlert!
Further information:
http://www.utoronto.ca

More articles from Materials Sciences:

nachricht Researchers printed graphene-like materials with inkjet
18.08.2017 | Aalto University

nachricht Superconductivity research reveals potential new state of matter
17.08.2017 | DOE/Los Alamos National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>