Wrinkles on the microparticles. Image source: Clouds Hill Imaging Ltd/Science Photo Library
Microscopic wrinkles that are squeezed onto the surface of fine plastic particles can be used to make security keys that are difficult to replicate.
Derek Breid of St. Vincent College in Pennsylvania, USA, said these randomly formed wrinkles resemble human fingerprints. Since each set of wrinkles is completely unique, these particles can be used to replace a security card or fingerprint to identify an individual. They are also used in precious works of art, so that people will be able to ensure that the real estate is traded.
The technology developer, Wook Park of Kyung Hee University in South Korea, said that keys made in this way are almost impossible to clone. Their method involves adding a thin layer of silica to the plastic pellets and then immersing them in ethanol for drying. As the particles dry out, the wrinkles formed within the silicone layer will produce a fingerprint-like structure.
Weak temperature differences or the effects of dust or other particles can make the structure unique. "This is a very chaotic random process," Breid said, making it almost impossible for others to accurately replicate the wrinkle pattern. Making wrinkles in this way is easier and less expensive than laser etching a particular labyrinth. “It’s very important not to use expensive production techniques,†he said.
Although the formation of this model is largely random, Park and the team have developed ways to control where some wrinkles are formed. They harden a portion of the plastic particles by placing them in daylight, and each hardened point forms a "decision point" where the wrinkles end, bend or separate.
Researchers can at least control some of these parameters and can easily share information. Controlling a group of particles in the same way (eg, bringing them into contact with the same light pattern) can form a matching set with similar decision points. Although the overall fingerprint is still random, the scanner reading the particle will be able to identify the location of the decision point, thus knowing a key belonging to a group of similar keys like a security card, that is, they can open the same door For this they can be shared among groups that have access to specific information.
Jan Genzer of North Carolina State University was impressed with the study. “You can control the length and shape of the wrinkles very well,†he said.
Park and the team are working on a smaller scanner to detect the pattern. They believe that it is more realistic to use a conductive scanner that can read surface electronic information in a secure system.
Steel Measuring Tape,Tape Line Measure,Magnet Tape Measure,Rubber Tape Line Measure
Shangqiu Hengli Measuring Tools Co.,Ltd , https://www.henglimtools.com