3.4 Fabrication of complicated tubular structures
We used the two-step crosslinking approach to fabricating a tubular structure of GelMA. The method of two-step crosslinking to construct tubular structure was showed in Figure 3E. Figure 3F showed the tubular construct with different diameters (0.08-0.2mm in lumen diameter and 0.6 mm in wall thickness). A 6 mm long tubular construct was showed in Figure 3G. SEM showed that the tubular structure has good bonding properties (Figure 3H).
Complicated designs demonstrated the advantages of two-step crosslinking method. We printed multiple curved tubular structure, branched tubular structure, circular tubular structure with single inlet/outlet, and several letters (Figure 4). Red inks were injected into these structures to show the connected channels within each structure and to demonstrate their integrity of fluid flow.