Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser

In this study, nanoscale periodic surface structures were fabricated on polyimide (PI) films using a linearly polarized KrF excimer laser with a wavelength of 248 nm. The effects of laser energy density and pulse number on the morphology and surface roughness of laser-induced periodic surface struct...

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Main Authors: Songqing Zhao, Xuan Xie, Mingyang Li, Limin Yang, Tongjing Liu
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/15/10/742
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author Songqing Zhao
Xuan Xie
Mingyang Li
Limin Yang
Tongjing Liu
author_facet Songqing Zhao
Xuan Xie
Mingyang Li
Limin Yang
Tongjing Liu
author_sort Songqing Zhao
collection DOAJ
description In this study, nanoscale periodic surface structures were fabricated on polyimide (PI) films using a linearly polarized KrF excimer laser with a wavelength of 248 nm. The effects of laser energy density and pulse number on the morphology and surface roughness of laser-induced periodic surface structures (LIPSSs) were systematically investigated. When the pulse width was 20 ns, the repetition rate was 10 Hz, and the beam incidence angle was normal (90°), periodic ripples with a spatial period of approximately 200 nm formed within an energy density range of 7–18 mJ/cm<sup>2</sup> and pulse number range of 6000–18,000. The most uniform and well-defined structures were achieved at 14.01 mJ/cm<sup>2</sup> and 12,000 pulses, with a ripple depth of 60 nm and surface roughness (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>R</mi><mi mathvariant="normal">a</mi></msub></semantics></math></inline-formula>) approximately 26 times greater than that of pristine PI. The ripple orientation was consistently perpendicular to the laser polarization, consistent with low-spatial-frequency LIPSS (LSFL) formation mechanisms governed by interference-induced photothermal effects. In addition, surface wettability was found to be significantly enhanced due to changes in both surface chemistry and topography, with the water contact angle decreasing from 73.7° to 19.7°. These results demonstrate the potential of UV nanosecond laser processing for the scalable fabrication of functional nanostructures on polymer surfaces for applications in surface engineering and biointerfaces.
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spelling doaj-art-573cd290f67d463a8e2829a8cbcf540f2025-08-20T03:48:01ZengMDPI AGNanomaterials2079-49912025-05-01151074210.3390/nano15100742Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer LaserSongqing Zhao0Xuan Xie1Mingyang Li2Limin Yang3Tongjing Liu4School of Science and Arts, China University of Petroleum-Beijing at Karamay, Karamay 834000, ChinaSchool of Science and Arts, China University of Petroleum-Beijing at Karamay, Karamay 834000, ChinaSchool of Science and Arts, China University of Petroleum-Beijing at Karamay, Karamay 834000, ChinaSchool of Science and Arts, China University of Petroleum-Beijing at Karamay, Karamay 834000, ChinaSchool of Petroleum, China University of Petroleum-Beijing at Karamay, Karamay 834000, ChinaIn this study, nanoscale periodic surface structures were fabricated on polyimide (PI) films using a linearly polarized KrF excimer laser with a wavelength of 248 nm. The effects of laser energy density and pulse number on the morphology and surface roughness of laser-induced periodic surface structures (LIPSSs) were systematically investigated. When the pulse width was 20 ns, the repetition rate was 10 Hz, and the beam incidence angle was normal (90°), periodic ripples with a spatial period of approximately 200 nm formed within an energy density range of 7–18 mJ/cm<sup>2</sup> and pulse number range of 6000–18,000. The most uniform and well-defined structures were achieved at 14.01 mJ/cm<sup>2</sup> and 12,000 pulses, with a ripple depth of 60 nm and surface roughness (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>R</mi><mi mathvariant="normal">a</mi></msub></semantics></math></inline-formula>) approximately 26 times greater than that of pristine PI. The ripple orientation was consistently perpendicular to the laser polarization, consistent with low-spatial-frequency LIPSS (LSFL) formation mechanisms governed by interference-induced photothermal effects. In addition, surface wettability was found to be significantly enhanced due to changes in both surface chemistry and topography, with the water contact angle decreasing from 73.7° to 19.7°. These results demonstrate the potential of UV nanosecond laser processing for the scalable fabrication of functional nanostructures on polymer surfaces for applications in surface engineering and biointerfaces.https://www.mdpi.com/2079-4991/15/10/742laser-induced periodic surface structurepolyimidenanostructureexcimer laserwettability
spellingShingle Songqing Zhao
Xuan Xie
Mingyang Li
Limin Yang
Tongjing Liu
Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser
Nanomaterials
laser-induced periodic surface structure
polyimide
nanostructure
excimer laser
wettability
title Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser
title_full Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser
title_fullStr Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser
title_full_unstemmed Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser
title_short Laser-Induced Periodic Nanostructure on Polyimide Film Surface Using 248 nm Excimer Laser
title_sort laser induced periodic nanostructure on polyimide film surface using 248 nm excimer laser
topic laser-induced periodic surface structure
polyimide
nanostructure
excimer laser
wettability
url https://www.mdpi.com/2079-4991/15/10/742
work_keys_str_mv AT songqingzhao laserinducedperiodicnanostructureonpolyimidefilmsurfaceusing248nmexcimerlaser
AT xuanxie laserinducedperiodicnanostructureonpolyimidefilmsurfaceusing248nmexcimerlaser
AT mingyangli laserinducedperiodicnanostructureonpolyimidefilmsurfaceusing248nmexcimerlaser
AT liminyang laserinducedperiodicnanostructureonpolyimidefilmsurfaceusing248nmexcimerlaser
AT tongjingliu laserinducedperiodicnanostructureonpolyimidefilmsurfaceusing248nmexcimerlaser