Liquid crystal doped photopolymer micro-droplets printed by a simple and clean laser-induced forward transfer process

We print a tunable photopolymer (photopolymer dispersed liquid crystal-PDLC), using the laser-induced direct transfer technique without absorber layer, which was a challenge for this technique given the low absorption and high viscosity of PDLC, and which had not been achieved so far to our knowledge. This makes the LIFT printing process faster and cleaner and achieves a high-quality printed droplet (aspheric profile and low roughness). A femtosecond laser was needed to reach sufficiently peak energies to induce nonlinear absorption and eject the polymer onto a substrate. Only a narrow energy window allows the material to be ejected without spattering.& COPY; 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

A tunable photopolymer (photopolymer dispersed liquid crystal-PDLC) was successfully printed using the laser-induced direct transfer technique without an absorber layer, which had been a challenge due to the low absorption and high viscosity of PDLC. The LIFT printing process was made faster and cleaner, resulting in high-quality printed droplets with aspheric profiles and low roughness. The use of a femtosecond laser and a narrow energy window was necessary for the polymer ejection without spattering.