An outline of Marilyn Monroe's iconic face appeared on the clear, plastic film when a researcher fogs it with her breath.
Terry Shyu, a doctoral student in chemical engineering at the University of Michigan, was demonstrating a new high-tech label for fighting drug counterfeiting. While the researchers don't envision movie stars on medicine bottles, but they used Monroe’s image to prove their concept.
Counterfeit drugs, which at best contain wrong doses and at worst are toxic, are thought to kill more than 700,000 people per year. While less than 1 percent of the U.S. pharmaceuticals market is believed to be counterfeit, it is a huge problem in the developing world where as much as a third of the available medicine is fake.
To fight back against these and other forms of counterfeiting, researchers at U-M and in South Korea have developed a way to make labels that change when you breathe on them, revealing a hidden image.
"One challenge in fighting counterfeiting is the need to stay ahead of the counterfeiters," said Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Chemical Engineering who led the Michigan effort.
The method requires access to sophisticated equipment that can create very tiny features, roughly 500 times smaller than the width of a human hair. But once the template is made, labels can be printed in large rolls at a cost of roughly one dollar per square inch. That's cheap enough for companies to use in protecting the reputation of their products—and potentially the safety of their consumers.
"We use a molding process," Shyu said, noting that this inexpensive manufacturing technique is also used to make plastic cups.
The labels work because an array of tiny pillars on the top of a surface effectively hides images written on the material beneath. Shyu compares the texture of the pillars to a submicroscopic toothbrush. The hidden images appear when the pillars trap moisture.
"You can verify that you have the real product with just a breath of air," Kotov said.
The simple phenomenon could make it easy for buyers to avoid being fooled by fake packaging.
Previously, it was impossible to make nanopillars through cheap molding processes because the pillars were made from materials that preferred adhering to the mold rather than whatever surface they were supposed to cover. To overcome this challenge, the team developed a special blend of polyurethane and an adhesive.
The liquid polymer filled the mold, but as it cured, the material shrunk slightly. This allowed the pillars to release easily. They are also strong enough to withstand rubbing, ensuring that the label would survive some wear, such as would occur during shipping. The usual material for making nanopillars is too brittle to survive handling well.
The team demonstrated the nanopillars could stick to plastics, fabric, paper and metal, and they anticipate that the arrays will also transfer easily to glass and leather.
Following seed funding from the National Science Foundation's Innovation Corps program and DARPA's Small Business Technology Transfer program, the university is pursuing patent protection for the intellectual property and is seeking commercialization partners to help bring the technology to market.
This work is reported in Advanced Materials in a paper titled, "Shear-Resistant Scalable Nanopillar Arrays with LBL-Patterned Overt and Covert Images."
It was funded by the Defense Advanced Research Projects Agency; the National Science Foundation; the Korea Ministry of Science, Information and Communications Technology and Future Planning; the Ministry of Knowledge Economy; and the Korea Evaluation Institute of Industry Technology.
Nicole Casal Moore | newswise
An engineered surface unsticks sticky water droplets
01.09.2015 | Penn State
New material science research may advance tech tools
01.09.2015 | Louisiana State University
The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.
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A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
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A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
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20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
01.09.2015 | Press release
01.09.2015 | Materials Sciences
01.09.2015 | Materials Sciences