High-speed atomic force microscopy combined with a laser irradiation system for the in-situ real-time observation of azo-polymer deformation process. Credit: Osaka University
Researchers from Osaka University have utilized combined microscopy to observe azo-polymer film behavior at the nanoscale. The novel in situ technique provides a unique opportunity to deepen our understanding of various optical devices.
In the study, published in Nano Letters, researchers used tip-scan high-speed atomic force microscopy (HS-AFM) and an optical microscope to capture changes in film behavior when triggered with laser light.
“It is usual to investigate changes in polymer films by subjecting them to a treatment, such as irradiating with light, and then making measurements or observations afterwards. However, this provides limited information,” said study lead author Keishi Yang. “Using an HS-AFM setup including an inverted optical microscope with a laser, allowed us to trigger changes in azo-polymer films while observing them in real time with high spatiotemporal resolution.”
The researchers tracked dynamic changes in the surfaces of the polymers using the HS-AFM measurements. Additionally, the team discovered that the direction of polarized light used influenced the final structure pattern of the polymers. The team anticipates the method leading to a more thorough understanding of the mechanisms behind light-driven azo-polymer deformation which will allow further optimization of their use.
“We have demonstrated our technique for observing polymer film deformation,” said senior author Takayuki Umakoshi. “However, in doing so, we have shown the potential of combining tip-scan HS-AFM and a laser source for use across materials science and physical chemistry.”
With recent attention on azo-polymers, thanks to their photoreactivity and potential use for numerous applications including optical data storage, the methods developed will allow for the optimization and maximization of azo-polymer uses in the future.