Two-Photon Polymerization Nanomanufacturing Based on the Definition-Reinforcement-Solidification (DRS) Strategy

Femtosecond laser additive manufacturing based on two-photon polymerization performs a useful technique for fabricating high-precision 3D structures. However, poor mechanical strength and low processing efficiency brought by near polymerization threshold processing to achieve high accuracy are still urgent problems. In this work, a definition-reinforcement-solidification (DRS) processing strategy is proposed to solve the current problems, in which DRS processing includes three steps: utilize a near-threshold femtosecond laser to accurately define the surface profile of 3D structures, perform enhanced scanning on the above structure's inner surface with a high-power femtosecond laser to increase the mechanical strength, and rapidly solidify the inner unpolymerized resin through one exposure of ultraviolet light to improve the processing efficiency. Compared with conventional near-threshold point-by-point direct writing, microstructures fabricated by the DRS strategy for a given geometry and polymer have hardness and Young's modulus values increase to 154% and 199%, respectively, and exhibit a 10000% improvement in machining efficiency without the loss of processing accuracy. Arbitrary complex 3D microstructures can be implemented rapidly via this strategy. This work will inject new vitality into two-photon polymerization additive manufacturing.

Automated summary

A new processing strategy (DRS) was proposed in this study, which enhances the mechanical strength and processing efficiency by using femtosecond laser for enhanced scanning on the inner surface of 3D structures and ultraviolet light exposure. This strategy addresses some of the issues in two-photon polymerization additive manufacturing.