3D microlattices fabricated through multi-photon lithography have been widely utilized for photonics, bio-scaffolds and architected metamaterials. Post-processing techniques have accentuated the reduction of the overall size to the nanoscale and the modification of the material properties of these structures. However, there are no processing techniques that can locally modify the morphology and the properties of microscale polymeric structures. In this study, our objective is to demonstrate localized nanoscale morphing and material modification of polymer 3D lattice structures through continuous wave laser induced selective pyrolysis, leading to local carbonization. Our approach of focused laser heating on single beam members precipitates thickness reduction from 500 nm to 250 nm. Local size reduction can further embrace collective mechanical deformation and form new complex geometries. Through spatially-variant laser heating on the periodic structures, curved and gradient three-dimensional shapes can be fabricated. Finite element analysis explained the resulted changes and predicted the enhanced mechanical performance. Ultimately, in situ scanning electron microscopy of the microindentation process proves that the modified structure demonstrates a substantially improved mechanical performance through the combination of high strength and ductility of the ceramic and polymer counterparts. Our findings and main results demonstrate the significance of the laser as a vital tool to ameliorate the geometrical complexity and material heterogeneity for enhanced mechanical performance. Supplementary material for this article is available online

中文翻译：

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用于 3D 微晶格受控变形和化学改性的激光热解

通过多光子光刻制造的 3D 微晶格已广泛用于光子学、生物支架和超材料。后处理技术强调了将整体尺寸减小到纳米级以及改变这些结构的材料特性。然而，没有可以局部改变微观聚合物结构的形态和性质的加工技术。在这项研究中，我们的目标是通过连续波激光诱导的选择性热解来证明聚合物 3D 晶格结构的局部纳米级变形和材料改性，从而导致局部碳化。我们在单光束部件上聚焦激光加热的方法使厚度从 500 nm 减少到 250 nm。局部尺寸减小可以进一步包含集体机械变形并形成新的复杂几何形状。通过对周期性结构进行空间变化的激光加热，可以制造弯曲和梯度的三维形状。有限元分析解释了导致的变化并预测了增强的机械性能。最终，微压痕过程的原位扫描电子显微镜证明，通过结合陶瓷和聚合物对应物的高强度和延展性，改性结构显示出显着改善的机械性能。我们的发现和主要结果证明了激光作为改善几何复杂性和材料异质性以提高机械性能的重要工具的重要性。