Fig. 4.
(a) Diagram of laser-based printing system. Reproduced with permission [86]. Copyright 2021, John Wiley and Sons. (b) Schematic of a laser-induced transfer printing system. Reproduced with permission [92]. Copyright 2021, John Wiley and Sons. (c) Schematic diagram illustrating the fabrication process of the customized NGC by using a rapid continuous 3D printing system. (c1-c2) The real figures of the 3D printed NGCs with one and four channels, respectively. (c, c1 and c2) Reproduced with permission [94]. Copyright 2021, Elsevier. (d) Schematic presenting the DLP-based manufacturing process of NGC made of GelMA. (d1) Confocal image of live/dead cell staining on the GelMA NGC. (d2) SEM image of the transverse section of the four-channel NGC. (d, d1 and d2) Reproduced with permission [95]. Copyright 1969, Elsevier.