Meena Narayana Menon Devanarayanan, Pugliese Diego, Giardino Matteo, Janner Davide
Department of Applied Science and Technology (DISAT) and RU INSTM, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
Materials (Basel). 2023 May 23;16(11):3899. doi: 10.3390/ma16113899.
In this study, a single-step nanosecond laser-induced generation of micro-optical features is demonstrated on an antibacterial bioresorbable Cu-doped calcium phosphate glass. The inverse Marangoni flow of the laser-generated melt is exploited for the fabrication of microlens arrays and diffraction gratings. The process is realized in a matter of few seconds and, by optimizing the laser parameters, micro-optical features with a smooth surface are obtained showing a good optical quality. The tunability of the microlens' dimensions is achieved by varying the laser power, allowing the obtaining of multi-focal microlenses that are of great interest for three-dimensional (3D) imaging. Furthermore, the microlens' shape can be tuned between hyperboloid and spherical. The fabricated microlenses exhibited good focusing and imaging performance and the variable focal lengths were measured experimentally, showing good agreement with the calculated values. The diffraction gratings obtained by this method showed the typical periodic pattern with a first-order efficiency of about 5.1%. Finally, the dissolution characteristics of the fabricated micropatterns were studied in a phosphate-buffered saline solution (PBS, pH = 7.4) demonstrating the bioresorbability of the micro-optical components. This study offers a new approach for the fabrication of micro-optics on bioresorbable glass, which could enable the manufacturing of new implantable optical sensing components for biomedical applications.
在本研究中，展示了在抗菌生物可吸收的铜掺杂磷酸钙玻璃上通过单步纳秒激光诱导生成微光学特征。利用激光产生的熔体的逆马兰戈尼流来制造微透镜阵列和衍射光栅。该过程在几秒钟内即可实现，并且通过优化激光参数，可以获得具有光滑表面且光学质量良好的微光学特征。通过改变激光功率可实现微透镜尺寸的可调性，从而获得对三维（3D）成像极具吸引力的多焦点微透镜。此外，微透镜的形状可以在双曲线体和球体之间进行调整。所制造的微透镜表现出良好的聚焦和成像性能，并且通过实验测量了可变焦距，其与计算值显示出良好的一致性。通过该方法获得的衍射光栅呈现出典型的周期性图案，一阶效率约为5.1%。最后，在磷酸盐缓冲盐水溶液（PBS，pH = 7.4）中研究了所制造的微图案的溶解特性，证明了微光学组件的生物可吸收性。本研究为在生物可吸收玻璃上制造微光学器件提供了一种新方法，这可能有助于制造用于生物医学应用的新型可植入光学传感组件。
