Microfabrication of Hydrogels Based on Femtosecond Laser Three-Dimensional Ablation

Hydrogels are widely used in biome dical applications such as drug delivery and tissue engineering. Micro-manufacturing of hydrogels can open new opportunities. Methods such as photolithography and soft lithography rely on masks for hydrogel shaping, while extrusion and inkjet printing are limited in their ability to achieve high-precision. On the other hand, femtosecond laser direct writing (FLDW) technology enables programmable construction of arbitrary microscopic patterns. Previous works of FLDW mainly focus on two-photon induced polymerization for 3D manufacturing. This study aims to exploit high-energy lasers to induce bond cleavage in polymers, achieving 3D subtractive processing of hydrogels. A resolution 900 nm was achieved. Moreover, the resulting patterned channels exhibit multicolor fluorescence, introducing a novel design concept that is significant for the development of diverse functionalized hydrogels水凝胶（hydrogels）被广泛应用于药物递送、组织工程等生物医学领域。水凝胶的微加工技术可为其带来全新发展机遇。诸如光刻（photolithography）与软刻蚀（soft lithography）这类成型工艺，需借助掩模完成水凝胶的塑形；而挤出成型与喷墨打印则难以实现高精度制备。另一方面，飞秒激光直写（FLDW）技术可实现任意微观图案的可编程化构建。既往飞秒激光直写技术的研究主要聚焦于双光子诱导聚合（two-photon induced polymerization），用于三维加工制造。本研究旨在利用高能激光诱导聚合物发生化学键断裂，从而实现水凝胶的三维减材加工，最终获得了900纳米的加工分辨率。此外，所制备的带图案通道可呈现多色荧光特性，由此提出了一种全新的设计理念，这对于开发多样化功能化水凝胶具有重要意义。