In this study, we evaluated the mechanical properties of printed structures with respect to the printing orientation for "SWIM-ER". The fracture surface of the 3D modeled object of the gel does not break along the stacked line, and the maximum stress at that time is the breaking strength. Moreover, the dependency in the stacking direction is weak in the 3D model of the gel. The gel printed at high speed scan showed lower elastic modulus and higher moisture content than gel printed at low speed scan. We discussed about crosslinking density calculated based on the compressive elastic modulus and moisture content, respectively. It was found that gels having different crosslinking density can be formed by the scanning speed of UV laser. In addition, we made a prototype of a gel finger model with different mechanical properties within the model.
Gels are soft and wet materials having low friction, good biocompatibility, and material permeability. It is expected that gel materials will be used as new kinds of industrial materials in the engineering and medical applications. But it cannot build a complicated shape. Soft & Wet Matter Engineering Laboratory developed a 3D gel Printer "SWIM-ER", has enabled modeling of complex shapes of the gel. However, this is expensive. Therefore not all of the gel researchers and the companies have such a device. To solve this problem, we manufacture a low-cost open-source 3D gel printer "RepRap SWIM-ER" from the RepRap. We made the components required to manufacture the “RepRap SWIM-ER” from the 3D printer and chose a light source. In addition, we produced the P-DN gel for RepRap SWIM-ER and conducted the molding test to confirm whether RepRap SWIM-ER can used it.
A 3D printer is a device which can directly produce objects whose shape is the same as the original 3D digital data.
Hydrogels have unique properties such as high water content, low frictional properties, biocompatibility, material
permeability and high transparency, which are rare in hard and dry materials. These superior characteristics of gels
promise useful medical applications. We have been working on the development of a 3D gel printer, SWIM-ER (Soft
and Wet Industrial – Easy Realizer), which can make models of organs and artificial blood vessels with gel material.
However, 3D printing has a problem: the mechanical properties of the printed object vary depending on printing
conditions, and this matter was investigated with SWIM-ER. In the past, we found that mechanical properties of 3D gel
objects depend on the deposition orientation in SWIM-ER. In this study, gels were printed with different laser scanning
speeds. The mechanical properties of these gels were investigated by compression tests, water content measurements and
SMILS (Scanning Microscopic Light Scattering).