Hot embossing of multifunctional transparent polymers from Cr stamps structured by direct laser interference patterning

Publikation: Beitrag in Buch/Konferenzbericht/Sammelband/GutachtenBeitrag in KonferenzbandBeigetragenBegutachtung

Beitragende

Abstract

In this contribution, Cr stamps were structured with periodic hole-like arrays using Direct Laser Interference Patterning. Using optimized laser processing parameters, homogeneous textures with different spatial periods and aspect ratios were produced, as observed with confocal microscopy. Then, these stamps were used as molds for patterning transparent polymers, namely polyethylene terephthalate (PET), poly(methyl methacrylate) (PMMA) and polycarbonate (PC) by plate-to-plate hot embossing. Adjusting the imprint time and temperature, replicas of the Cr stamps were fabricated reproducing faithfully the mold shape. Static water contact angle (WCA) measurements were done to study the wettability properties of these structured polymers. The results show that the produced topographies increase the WCA compared to the flat references up to an absolute maximum of 55° in the three polymers. For instance, a PET foil structured with a spatial period of 4.7 μm and a structured depth of 3 μm showed a WCA of 139° representing an increase of about 70% compared to a flat sample. The diffraction intensity of the patterned polymers was measured with an imaging optics and a spectrometer coupled to a goniometer in order to characterize their optical properties. It was found that for those samples processed with 80 or less applied laser pulses the diffraction peaks are clearly identified, whereas for large number of pulses there is more diffuse light travelling along random directions and the diffraction peaks become less defined. In conclusion, enhanced wettability and optical functionalities were achieved in transparent polymers imprinted with periodic microstructures.

Details

OriginalspracheEnglisch
TitelLaser-Based Micro- and Nanoprocessing XIV
Redakteure/-innenUdo Klotzbach, Akira Watanabe, Rainer Kling
Herausgeber (Verlag)SPIE - The international society for optics and photonics
ISBN (elektronisch)9781510632998
PublikationsstatusVeröffentlicht - 2020
Peer-Review-StatusJa

Publikationsreihe

ReiheProceedings of SPIE - The International Society for Optical Engineering
Band11268
ISSN0277-786X

Konferenz

TitelLaser-Based Micro- and Nanoprocessing XIV 2020
Dauer3 - 6 Februar 2020
StadtSan Francisco
LandUSA/Vereinigte Staaten

Externe IDs

ORCID /0000-0002-0666-3273/work/173055836
ORCID /0000-0003-4333-4636/work/196675513

Schlagworte

Schlagwörter

  • Diffraction gratings, Direct laser interference patterning, Hydrophobicity, Nanoimprint lithography, Thermoplastics, Wettability