Cornell University School of Mechanical Engineering, Ithaca NY, USA.
MIT, Computer Science and Artificial Intelligence Lab, 32 Vassar St. Cambridge MA, USA.
Sci Rep. 2016 Aug 9;6:29996. doi: 10.1038/srep29996.
Additive manufacturing of cellular structures has numerous applications ranging from fabrication of biological scaffolds and medical implants, to mechanical weight reduction and control over mechanical properties. Various additive manufacturing processes have been used to produce open regular cellular structures limited only by the resolution of the printer. These efforts have focused on printing explicitly designed cells or explicitly planning offsets between strands. Here we describe a technique for producing cellular structures implicitly by inducing viscous thread instability when extruding material. This process allows us to produce complex cellular structures at a scale that is finer than the native resolution of the printer. We demonstrate tunable effective elastic modulus and density that span two orders of magnitude. Fine grained cellular structures allow for fabrication of foams for use in a wide range of fields ranging from bioengineering, to robotics to food printing.
细胞结构的增材制造具有许多应用，从生物支架和医疗植入物的制造，到机械减重和控制机械性能。已经使用了各种增材制造工艺来生产开放的规则细胞结构，其限制仅在于打印机的分辨率。这些努力集中在打印明确设计的细胞或明确规划线之间的偏移量。在这里，我们描述了一种通过在挤出材料时诱导粘性线不稳定性来间接产生细胞结构的技术。该过程使我们能够以比打印机的固有分辨率更精细的尺度生产复杂的细胞结构。我们展示了可调节的有效弹性模量和密度，跨越两个数量级。细晶粒细胞结构允许制造泡沫，可用于从生物工程到机器人技术再到食品打印的广泛领域。
