Menne David, Lemos da Silva Lucas, Rotan Magnus, Glaum Julia, Hinterstein Manuel, Willenbacher Norbert
Institute for Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, Gotthard-Franz-Strasse 3, 76131 Karlsruhe, Germany.
Institute for Applied Materials Ceramic Materials and Technologies, Karlsruhe Institute of Technology, Haid-und-Neu Strasse 7, 76131 Karlsruhe, Germany.
ACS Appl Mater Interfaces. 2022 Jan 19;14(2):3027-3037. doi: 10.1021/acsami.1c19297. Epub 2022 Jan 5.
Dedicated hierarchical structuring of functional ceramics can be used to shift the limits of functionality. This work presents the manufacturing of highly open porous, hierarchically structured barium titanate ceramics with 3-3 connectivity direct ink writing of capillary suspension-type inks. The pore size of the printed struts (∼1 μm) is combined with a printed mesostructure (∼100 μm). The self-organized particle network, driven by strong capillary forces in the ternary solid/fluid/fluid ink, results in a high strut porosity, and the distinct flow properties of the ink allow for printing high strut size to pore size ratios, resulting in total porosities >60%. These unique and highly porous additive manufactured log-pile structures with closed bottom and top layers enable tailored dielectric and electromechanical coupling, resulting in an energy harvesting figure of merit FOM more than four times higher than any documented data for barium titanate. This clearly demonstrates that combining additive manufacturing of capillary suspensions in combination with appropriate sintering allows for creation of complex architected 3D structures with unprecedented properties. This opens up opportunities in a broad variety of applications, including electromechanical energy harvesting, electrode materials for batteries or fuel cells, thermoelectrics, or bone tissue engineering with piezoelectrically stimulated cell growth.
功能性陶瓷的专用分层结构可用于突破功能极限。本文介绍了具有3-3连通性的高度开放多孔、分层结构的钛酸钡陶瓷的制造方法，即采用毛细管悬浮型油墨进行直接墨水书写。打印支柱的孔径（约1μm）与打印的介观结构（约100μm）相结合。在三元固体/流体/流体油墨中，由强大的毛细管力驱动的自组织颗粒网络导致了较高的支柱孔隙率，并且油墨独特的流动特性使得能够打印高支柱尺寸与孔径比，从而实现总孔隙率>60%。这些具有封闭底层和顶层的独特且高度多孔的增材制造原木堆结构能够实现定制的介电和机电耦合，从而使能量收集品质因数FOM比任何已记录的钛酸钡数据高出四倍以上。这清楚地表明，将毛细管悬浮液的增材制造与适当的烧结相结合，可以制造出具有前所未有的性能的复杂三维结构。这为包括机电能量收集、电池或燃料电池的电极材料、热电学或具有压电刺激细胞生长的骨组织工程在内的广泛应用开辟了机会。
