Kam Doron, Rulf Omri, Reisinger Amir, Lieberman Rama, Magdassi Shlomo
The Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
Nat Commun. 2024 Mar 13;15(1):2285. doi: 10.1038/s41467-024-46532-0.
Additive manufacturing technologies based on stereolithography rely on initiating spatial photopolymerization by using photoinitiators activated by UV-visible light. Many applications requiring printing in water are limited since water-soluble photoinitiators are scarce, and their price is skyrocketing. On the contrary, thermal initiators are widely used in the chemical industry for polymerization processes due to their low cost and simplicity of initiation by heat at low temperatures. However, such initiators were never used in 3D printing technologies, such as vat photopolymerization stereolithography, since localizing the heat at specific printing voxels is impossible. Here we propose using a thermal initiator for 3D printing for localized polymerization processes by near-infrared and visible light irradiation without conventional photoinitiators. This is enabled by using gold nanorods or silver nanoparticles at very low concentrations as photothermal converters in aqueous and non-aqueous mediums. Our proof of concept demonstrates the fabrication of hydrogel and polymeric objects using stereolithography-based 3D printers, vat photopolymerization, and two-photon printing.
基于立体光刻的增材制造技术依靠使用由紫外-可见光激活的光引发剂来引发空间光聚合反应。许多需要在水中进行打印的应用受到限制，因为水溶性光引发剂稀缺且价格飞涨。相反，热引发剂因其成本低且在低温下通过加热引发反应的操作简单，而在化学工业的聚合过程中被广泛使用。然而，此类引发剂从未用于3D打印技术，如桶式光聚合立体光刻，因为无法将热量定位在特定的打印体素上。在此，我们提出在没有传统光引发剂的情况下，通过近红外和可见光照射，将热引发剂用于3D打印以进行局部聚合过程。这是通过在水性和非水性介质中使用极低浓度的金纳米棒或银纳米颗粒作为光热转换器来实现的。我们的概念验证展示了使用基于立体光刻的3D打印机、桶式光聚合和双光子打印来制造水凝胶和聚合物物体。
