Electrohydrodynamic Liquid Bridge Printing of Complex 3D Architectures Using Biopolymeric Inks

Electrohydrodynamic direct writing (EHDDW) has demonstrated significant advantages in fabricating high-resolution structures for biomedical applications. However, the limited biopolymers for thick architectures and the low geometric complexity constrain the broader application of EHDDW. Here, an electrohydrodynamic liquid bridge (ELB) printing method is reported that expands the boundaries of available materials and structural complexities in EHDDW, while retaining its high-resolution capabilities. This method employs an ELB for stable and controllable deposition of tiny ink, coupled with in situ UV illumination for the rapid solidification of the ink. ELB printing allows to fabricate a variety of synthetic and natural biopolymers into solid or hydrogel architectures with heights of 5 mm and a resolution of up to 20 µm, while also facilitating the creation of complex geometries with intricate internal structures. The application of ELB printing in producing advanced scaffolds is further demonstrated, including 4D-printed anisotropic cylinders and highly porous, cartilage-biomimetic hydrogels. The ELB printing provides a versatile and high-resolution technique for scaffold fabrication in tissue engineering.