TU-TESL

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According to foreign media reports, five years ago, Jeffrey Pyun, a material scientist at the University of Arizona, showed Robert Norwood, an optical scientist, the first generation of orange plastic lenses he developed. "No one wants an orange lens," Robert Norwood replied Since then, puyn has led a team to improve materials and create a new generation of lenses. The plastic is a sulfur-containing polymer forged from waste generated from refining fossil fuels and is particularly suitable for lenses, windows and other devices that need to transmit infrared (IR). Pyun, a professor in the Department of chemistry and biochemistry, led the laboratory in developing the polymer. "Infrared imaging technology has been widely used in the military, such as night vision and heat seeking missiles," he said. But for consumer goods and transportation, the cost of this technology is too high, limiting mass production. " According to Professor Norwood, the new materials used in lenses make IR cameras and sensor devices cheaper and easier for consumers to use. Potential consumer applications include affordable cars and home thermal imaging for safety or fire protection. Compared with the first generation of infrared medium wavelength transparent sulfur-containing plastics developed in 2014, the new polymer is stronger and more heat-resistant. The new lens is transparent in a wider spectral window, and its spectrum can be extended to long wave IR, and it is much cheaper than the existing industrial standard germanium metal lens. Germanium is an expensive, heavy, rare and toxic material. Due to the shortcomings of germanium, Tristan Kleine, a graduate student in puyn laboratory and the first author of the paper, believes that sulfur-containing plastics are an attractive alternative material. But making transparent plastic is a tricky business. Kleine says components that produce useful optical properties, such as sulfur sulfur bonds, can also damage the strength and heat resistance of the material. In addition, because almost all organic molecules will absorb IR light, other organic molecules increased in order to increase the strength of the material will lead to the decrease of transparency. In order to overcome these challenges, Kleine, in collaboration with Meghan Talbot, a graduate student in the Department of chemistry, and Dennis lichtenberger, a professor in the Department of chemistry and biochemistry, designed IR free organic molecules by computer simulation and predicted the transparency of candidate materials. "It may take years to test such materials in the laboratory, but using this method can greatly speed up the design of new materials," Kleine said It takes more than 1700 degrees Fahrenheit (926.67 degrees Celsius) to melt and form germanium. However, because sulfur polymer lenses contain special chemicals, they can be formed at lower temperatures. "One of the main advantages of this new sulfur-containing plastic is that it can be processed into useful optical elements for cameras or sensors at lower temperatures than germanium, while maintaining good thermomechanical properties to prevent cracking or scratches," Pyun said Norwood added: "the reliability of this material is basically the same as that of the optical polymer used in glasses." (all pictures are from the University of Arizona)