Bottlebrush Polymers for Multiphoton 3D Laser Printing

Multiphoton 3D laser printing (MPLP) serves as a powerful tool for shaping materials into complex microstructures with high precision, resolution, and fidelity. Hereby, MPLP predominantly relies on linear prepolymers, while the potential of more complex polymer architecture remains largely unexplored. Bottlebrush polymers (BBPs), characterized by densely grafted side chains emanating from a singular backbone, offer unique properties that could expand the capabilities of MPLP. Herein, a new class of inks for MPLP, based on BBPs, is investigated and systematically evaluated in terms of their printability and mechanical performance. BBPs with different backbone lengths were synthesized and 3D printed to examine the influence of the polymer architecture. Through in-depth characterization of the resultant printed structures using scanning electron microscopy, Fourier-transform infrared spectroscopy, and nanoindentation, the BBPs are shown to have superior printability as well as softer mechanical properties, when compared to linear analogues. By introducing architecturally complex polymers to MPLP, this work expands the material design space for advanced 3D microfabrication and opens new opportunities for application-driven structures requiring tailored properties and functionality.