Blankenship Brian W, Pan Daisong, Kyriakou Eudokia, Zyla Gordon, Meier Timon, Arvin Sophia, Seymour Nathan, De La Torre Natalia, Farsari Maria, Ji Na, Grigoropoulos Costas P
Laser Thermal Laboratory, Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States.
Department of Physics, University of California, Berkeley, California 94720, United States.
ACS Appl Mater Interfaces. 2025 Jan 15;17(2):3887-3896. doi: 10.1021/acsami.4c16509. Epub 2025 Jan 3.
Microadditive manufacturing has revolutionized the production of complex, nano- to microscale components across various fields. This work investigates two-photon (2P) and three-photon (3P) fluorescence imaging, as well as third-harmonic generation (THG) microscopy, to examine periodic microarchitected lattice structures fabricated using multiphoton lithography (MPL). By immersing the structures in refractive index matching fluids, we demonstrate high-fidelity 3D reconstructions of both fluorescent structures using 2P and 3P microscopy as well as low-fluorescence structures using THG microscopy. These results show that multiphoton fluorescence (MPF) imaging offers reduced signal decay with respect to depth compared to single-photon techniques in the examined structures. We further demonstrate the ability to nondestructively identify intentional internal modifications of the structure that are not immediately visible with scanning electron microscope (SEM) images and compression-induced fractures, highlighting the potential of these techniques for quality control and defect detection in microadditively manufactured components.
微纳增材制造彻底改变了各个领域中复杂的纳米至微米级组件的生产方式。这项工作研究了双光子（2P）和三光子（3P）荧光成像以及三次谐波产生（THG）显微镜技术，以检查使用多光子光刻（MPL）制造的周期性微结构晶格结构。通过将这些结构浸入折射率匹配液中，我们展示了使用2P和THG显微镜对荧光结构进行的高保真3D重建，以及使用THG显微镜对低荧光结构进行的高保真3D重建。这些结果表明，与单光子技术相比，多光子荧光（MPF）成像在被检查结构中随深度的信号衰减更小。我们进一步展示了无损识别结构中那些在扫描电子显微镜（SEM）图像中无法立即看到的故意内部修改以及压缩引起的裂缝的能力，突出了这些技术在微纳增材制造组件的质量控制和缺陷检测方面的潜力。
