Cheng Der-Yun, Tai Wen-Chien, Liao Ying-Chih
Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
ACS Appl Mater Interfaces. 2024 Aug 28;16(34):45589-45597. doi: 10.1021/acsami.4c10858. Epub 2024 Aug 19.
In this research, a foam three-dimensional (3D) printing method using digital light processing (DLP) technology was developed to fabricate 3D-printed porous structures. To address the challenges in preparing DLP precursor foam fluid, we designed a specialized foaming device. This device enables the precursor solution to be blended with air, resulting in a stable foam precursor with an adjustable air/liquid fraction and suitable fluidity, crucially enhancing the gas-liquid contact time for the printing process. By manipulation of fluid flow rates, cycle counts, and gas/liquid ratios, one can easily prepare uniform foams with precise control over the pore size and porosity. To avoid significant volume reduction during ultraviolet (UV) curing, nanoparticle fillers were introduced into the network to prevent collapse of the foam structure. Furthermore, the inclusion of an UV absorber enhanced the quality of the printing process by addressing the limitations associated with particle scattering and reflection. The DLP process can readily fabricate intricate structures, featuring a planar resolution below 30 μm and a printing accuracy of less than 1%. Several examples were also demonstrated to highlight the advantages of this technology and its ability to directly print custom foam structures, thereby saving time and material resources.
在本研究中，开发了一种使用数字光处理（DLP）技术的泡沫三维（3D）打印方法来制造3D打印多孔结构。为应对制备DLP前驱体泡沫流体时的挑战，我们设计了一种专门的发泡装置。该装置能使前驱体溶液与空气混合，产生具有可调气/液比和合适流动性的稳定泡沫前驱体，这对提高打印过程中的气液接触时间至关重要。通过控制流体流速、循环次数和气/液比，人们可以轻松制备出孔径和孔隙率可控的均匀泡沫。为避免在紫外线（UV）固化过程中体积大幅减小，在网络中引入了纳米颗粒填料以防止泡沫结构坍塌。此外，加入紫外线吸收剂解决了与颗粒散射和反射相关的限制，提高了打印过程的质量。DLP工艺能够轻松制造复杂结构，平面分辨率低于30μm，打印精度小于1%。还展示了几个实例，以突出该技术的优势及其直接打印定制泡沫结构的能力，从而节省时间和材料资源。
