Tech Blog: UA Invents “CHIPs,” a novel plastic for infrared imaging

Almost everyone has seen a movie or TV show where a secret military group is using night vision-type technology to see through a building and pick up a multi-colored image known as a heat signature. This is made possible via infrared imaging.

Humans maintain an equilibrium temperature; in other words, we emit light in the infrared spectrum. In comparison to visible wavelengths of light, the light waves we emit are longer than what we can see with our eyes, which is why we need special imaging equipment to see them.

Typically, lens materials for infrared imaging, also known as transmissive materials, require chalcogenide glass, which is a “glass containing one or more chalcogens (sulfur, selenium and tellurium)” [1]. While working on materials for batteries, a process that requires a lot of sulfur chemistry, Jeffrey Pyun Ph.D., professor in the University of Arizona’s Department of Chemistry and Biochemistry, developed a new class of inexpensive, ultra-high refractive index polymers with properties that uniquely suited them for use as optical plastics – something that had never be done before. He called this new hybrid material CHIPs, which stands for Chalcogenide Hybrid Inorganic/organic Polymers.

“We think we have a revolutionary breakthrough here because most plastics will be completely opaque when used in thermal imaging applications. It’s like taking a book and trying to see through it. What is really neat about our polymers is that they are made of a feedstock that is completely different from most other classical plastics. They have really great infrared transparency, in fact, they have the highest refractive index of any synthetic polymer ever made. Period.”

This research, a collaboration between Pyun, Optical Sciences Professor Robert Norwood, and Chemistry and Biochemistry Professor Richard Glass, has led to the development of numerous exciting technologies for use in the mid-IR spectrum.

“For the first time, we have something that is really cheap and is serendipitously uniquely suited for this application.”

Pyun envisions success for these plastics in three different areas where infrared imaging is put to use, including high-value technologies like those used in defense, specialty plastics and commodities like smartphones, which he finds to be the most intriguing application.

“There is a heat signature for ripe versus not ripe tomatoes so instead of squeezing every one, you could just use your phone. We can continue to drop the price of making this possible with cheaper components, like our sulfur plastics. Those are the kinds of things we’re excited about.”

To learn more about these technologies, visit:

• UA17-153 Solution Processable Chalcogenide Hybrid Inorganic/Organic Polymers (CHIPs) for Optical Short-Wave Infrared and Mid-Infrared Mirrors and Reflectors
• UA17-158 Reinforced Chalcogenide Hybrid Inorganic/Organic Polymers (CHIPs) Composites with Isorefractive Fillers

To learn more about all of Jeff Pyun's available technologies, visit http://inventions.arizona.edu/inventors/13381816_dong-chul-jeffrey-pyun.

Listen and Learn: Click to hear(link is external) the inaugural episode of the Invented Arizona Podcast, featuring these technologies!

References:

[1] “Chalcogenide glass.” Wikipedia, Wikimedia Foundation, 8 Dec. 2016, en.wikipedia.org/wiki/Chalcogenide_glass. Accessed 14 June 2017.