Femtosecond laser printing patterned nanoparticles on flexible substrate by tuning plasmon resonances via polarization modulation.

Nanoparticles patterned on stretchable films for broad applications lack efficient fabrication methods. In this study, femtosecond laser-induced transfer was employed to assemble nanoparticles into a well-defined array on a flexible substrate while mitigating the inevitable plasmon resonances. The metal islands patterned on the substrate are regularly transferred as spherical nanoparticles onto the polymer, with a small deposition deviation and large embedded depth after laser irradiation. However, inhomogeneous laser absorption in the patterned array severely amplifies the printing deviation and narrows the process window, particularly for smaller patterns and complex arrangements. Plasmon resonance excited by an incident laser causes a localized optical field distribution, which accounts for absorption enhancement or suppression. The field distribution from the numerical simulation exhibited periodicity related to the laser parameters and array geometry. A theoretical model was established to clarify the propagation of plasmon resonance waves. The field distribution was modulated by adjusting the polarization direction, guided by theoretical and simulation analyses. Finally, regular and complex nanoparticle arrays were successfully fabricated after tuning the plasmon resonances. This study provides an effective method for fabricating programmable nanoparticle arrays on flexible films. [Display omitted] • Femtosecond laser-induced transfer is employed to print the small-scale and well-defined nanoparticles array with inevitable plasmons. • The effects of laser pulse energy and array geometry on the position and size deviations of printed nanoparticles are revealed. • Excitation, reflection, and superposition of the plasmon resonances in patterned island arrays are demonstrated by numerical simulation and theoretical analysis. • The uniformity and accuracy of nanoparticle arrays are improved significantly by adjusting the polarization direction. [ABSTRACT FROM AUTHOR]