Laser photonic nanojets triggered thermoplasmonic micro/nanofabrication of polymer materials for enhanced resolution

Abstract

Micro/nanofabrication of polymer materials is of interest for micro/nanofluidic systems. Due to the optical diffraction limit, it remains a challenge to achieve nanoscale resolution fabrication using an ordinary continuous-wave laser system. In this study, we therefore propose a laser photonic nanojet-based micro/nanofabrication method for polymer materials using a low-power and low-cost continuous-wave laser. The photonic nanojets were produced using glass microspheres. Moreover, a thermoplasmonic effect was employed by depositing a gold layer beneath the polymer films. By applying the photonic nanojet triggered thermoplasmonics, sub-micrometer surface structures, as well as their arrays, were fabricated with a laser power threshold value down to 10 mW. The influences of the microsphere diameters, and thicknesses of gold layers and polymer films on the fabricated microstructures were systematically investigated, which aligns well with the finite-difference time-domain simulation results.

Chemical Method Based on Thermally Activated Free Radical Polymerization to Determine the Temperature in Thermoplasmonics

“…Heating generated by laser-illuminated metal nanoparticles (NPs), known as the thermoplasmonic effect, is finding more and more applications , in both biology and chemistry. , In biology, thermoplasmonics can be used to kill cancer cells − or to observe living organisms requiring high temperatures, known as thermophiles, directly under a microscope. In chemistry, the deliberate and controlled heating of nanoparticles can accelerate chemical reactions or enable the development of lithography techniques …”

“…In chemistry, the deliberate and controlled heating of nanoparticles can accelerate chemical reactions 10 or enable the development of lithography techniques. 11 The thermoplasmonic effect is present as soon as a plasmon (i.e., collective oscillations of free electrons of the metal) is generated at the surface of a NP, i.e., as soon as one or more NPs are illuminated. So, whatever the final aim of the experiment is, it is important to be able to quantify the heat generated by the sample.…”