TAGS: Smart Coatings
Researchers use microstructures to create color-shifting coatings which, unlike the typical iridescent nanostructures, are more customizable due to their size and shape. By using this new class of microstructures, security features can be designed that are more tunable in their colors and patterns.
Microstructures for Tunable Security Patterns
“Creating iridescence typically requires materials to be patterned with very small nanostructures which cause light to undergo interference when it gets reflected. We realized there is actually another way to produce interference using a different type of reflective geometry 100 or even up to 1,000 times larger in size, leading to unique color-shifting appearances,” said Caleb Meredith, Chromatir co-founder and CEO and doctoral candidate in the department of materials science and engineering.
“A traditional hologram is basically a bunch of dots or lines – you can change the spacing of the structures or their width, but it can only be controlled along one or two dimensions,” said Meredith.
“
Whereas, with the microstructures we are designing, you’re playing with geometries in 3D, and so there are more degrees of freedom by which we can use to control the shape. You can make a structure wider or deeper, change the slope of its sides, make it into a polygon or a donut shape -- varying the shapes in each of these ways lead to differences in light’s reflections that result in subtle changes in color-shifts. By controlling the shapes of the microstructures, you control the color.”
Co-founders Lauren Zarzar, assistant professor in the Eberly College of Science, and Meredith published their original discovery of the optical mechanism in Nature led by Amy Goodling in 2019, a few years after the initial observation. After publishing, they started considering how the technology could be developed into a possible application for licensing, or eventually the core of a feasible business, and this year they officially incorporated Chromatir as an LLC.
“
A lot of important developments recently have been on the customer discovery side,” Meredith said.
“We’ve been able to talk to lots of different companies about security, packaging, and other decorative applications, and learn about what their problems are and where we think we can present solutions.”
Although Meredith and Zarzar are currently focused on the security applications of their color shifting films, they are also investigating other applications, such as decorative graphics for vehicles, consumer packaging, and apparel, as well as reflective road signs and color changing sensors.
Taking Lab Ideas to Potential Product on Market
To take Chromatir’s technology from just an idea in a lab to a potential product on the market, Meredith and Zarzar have acquired mentors through the many entrepreneurial resources at Penn State.
Meredith said Chromatir is close to completing a large manufacturing trial to validate the scalability of the color shifting films using roll-to-roll coating processes. Meredith is also participating in the inaugural On Deck Deep Tech Fellowship, an international cohort-based virtual program for scientists and entrepreneurs interested in commercializing technologies with substantial scientific and engineering challenges.
“We’ve had a lot of people be supportive of us at Penn State - people in the Office of Technology Management, people in the Startup Leadership Network, Penn State alumni, the list goes on,” Zarzar said. “
There’s a lot of entrepreneurial infrastructure being developed at the university and people reaching out who have been really necessary and supportive in helping to get us this far.”
Source: Penn State