Rapid digital light 3D printing enabled by a soft and deformable hydrogel separation interface

The low productivity of typical 3D printing is a major hurdle for its utilization in large-scale manufacturing. Innovative techniques have been developed to break the limitation of printing speed, however, sophisticated facilities or costly consumables are required, which still substantially restricts the economic efficiency. Here we report that a common stereolithographic 3D printing facility can achieve a very high printing speed (400 mm/h) using a green and inexpensive hydrogel as a separation interface against the cured part. In sharp contrast to other techniques, the unique separation mechanism relies on the large recoverable deformation along the thickness direction of the hydrogel interface during the layer-wise printing. The hydrogel needs to be extraordinarily soft and unusually thick to remarkably reduce the adhesion force which is a key factor for achieving rapid 3D printing. This technique shows excellent printing stability even for fabricating large continuous solid structures, which is extremely challenging for other rapid 3D printing techniques. The printing process is highly robust for fabricating diversified materials with various functions. With the advantages mentioned above, the presented technique is believed to make a large impact on large-scale manufacturing. The commercial application of 3D printing is limited by time constraints and current efforts to speed the process are economically inefficient. Here the authors report on the use of a green and inexpensive hydrogel to separate the interface and cured components in common stereolithographic processes to allow for rapid printing.