Anti-counterfeiting label thanks to the image displayed by the breath

Anti-counterfeiting security technologies such as 3-dimensional virtual images are currently being used on money and product stamps can still be copied. Therefore, users need a simpler new method to distinguish counterfeit goods but still sophisticated enough to imitate criminals. Thanks to the new nano printing technique, researchers were able to create a kind of label containing hidden patterns and only appear when we breathe on it. These labels can be designed in a variety of scales, durable and can be printed on a variety of surfaces.

Counterfeit products, especially pharmaceuticals, often contain misleading and even toxic ingredients. These products are thought to cause death to more than 700,000 people worldwide each year. Although counterfeit products account for only about 1% of the US pharmaceutical market, this is a major problem in developing countries. So, the University of Michigan (UMICH) and researchers in Korea developed a security label solution that contained hidden images and only appeared when breathing.

Nicholas Kotov, a professor from the University of Michigan's Department of Chemical Engineering, said: "One of the challenges to counterfeiting is that we must always stay ahead of the counterfeiter."

Kotov and his colleagues exploited the process of making molds and polymer materials containing nanotubes - a material currently used in many areas such as wearable electronics or solar cells. This type of material was previously difficult to work with low-cost molding processes because it often sticks to small holes of the mold instead of sticking to the fixed surfaces. However, the team has improved the material with glue and polyurethane, allowing the material to stretch and pull easily from the mold, while helping the material to adhere to a variety of surfaces such as plastic, fiber, paper and metal. In addition, the material can resist scratching.

In order to create a hidden anti-counterfeiting image, the polymer sheets that were molded with 20cm diameter will be put into a special printer, which works quite like an inkjet printer. The printer will "squid" the nano columns and the space between the nano columns, thereby creating a pattern. When we breathe on a polymer sheet, moisture in the breath will condense on the surface, revealing the hidden pattern inside.

According to the research team, once the model has been created, the label can be printed on large rolls at a relatively low cost, about 1 USD per square inch. With low prices, companies can use labels to protect product reputation as well as ensure safety and consumer rights.

Research by the University of Michigan and scientists in Korea has been funded under the Small Business Technology Transformation Program of the Advanced Defense Projects Agency (DARPA) and the National Science Foundation (NSF). USA. The University of Michigan has also patented technology and is currently seeking commercial partners to bring this technology to market.