Watch the new episode of Invented Arizona, where we speak with Anthony Muscat about the development of his metallic nanoparticle coatings.
In the complex world of semiconductors, innovators have been working to find new and better methods for electrostatic plating of metal nanoparticles on insulator surfaces. While current processes for depositing metal are fast and efficient, they require corrosive and toxic chemical bathes as well as initial deposition of a seed layer to get the process started. Several technologies have attempted to alleviate these issues, but a technique to inexpensively and efficiently apply such very thin layers (under 10 nanometers) of a metal coating has yet to enter the market.
Anthony Muscat, Ph.D., professor and chair of the Department of Chemical and Environmental Engineering in the College of Engineering at the University of Arizona, set out to remedy this by developing a process to deposit a very thin coating of metal using metal nanoparticles by only the electrostatic interaction between the nanoparticles and a suitably prepared substrate surface like silica, glass or other metals.
To do so, Muscat starts with a “glue layer”, where the glue on one side sticks to the surface, while the other side bonds with the particular metal of interest. Once the glue layer is deposited, metal nanoparticles are created and deposited onto the surface, resulting in a very thin, uniform coating.
Each nanoparticle measures on the order of 3 to 10 nanometers; to provide an idea of scale, about 10,000 nanoparticles can span the width of an average human hair, which is about 20 microns.
“The small size is an advantage because we can cover materials very efficiently. Even small corners can be covered well because the particles are small.” Muscat noted that while this technology is well suited for use in the semiconductor industry, it is applicable in industries like satellites and sensing. Because this new process removes the need for applied voltage during the electroplating process and is achievable at fairly low temperatures (about 200 degrees Celsius or less), it opens the door to depositing metals onto plastics, a practice that has, until now, been otherwise unachievable. For example, in satellites that require electrically conductive surfaces and light payloads but also contain a significant amount of plastic, this technology could metalize said plastic through the creation of such thin layers.
The technology is even applicable in the medical industry. “We have worked with a company in the medical supply space who wanted to take a metal chamber and deposit another metal onto it in order to get a particular property for a device they’re building. After finding that gold does not adhere well to aluminum despite the presence of a glue layer, we applied for Asset Development funding from Tech Launch Arizona to continue researching how the glue layer works so that we could scale up the process.”
Tech Launch Arizona’s Asset Development funding helps to advance technology and validate market potential in inventions that are not yet ready for commercialization. The office awarded Muscat the funding to develop the technology in 2016.
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Learn more about other coating-related technologies from the University of Arizona: