The purpose of this study is to evaluate the deformation behavior of 3D printed specimens using the small punch tensile test method. Traditional tensile tests for assessing mechanical properties require a significant amount of material to produce uniaxial tensile specimens. In contrast, the small punch test method only requires 10 x 10 x 0.5 mm (width x length x thickness) thin plate specimens, providing a substantial economic advantage in specimen sampling and production. This method is particularly beneficial when it is impossible to produce specimens of the same size as uniaxial specimens, as it allows tensile testing with just the minimum sample required. In this study, we utilized fused deposition modeling 3D printing and considered various 3D printing parameters, such as layer height and volume fraction, while manufacturing the specimens. We then compared and analyzed the effects of these variables on tensile strength as measured by the small punch tensile test. Furthermore, we focused on investigating the applicability of this method to the deformation behavior of 3D printed specimens. We also examined the impact of laminating conditions, including layer height, printing speed, and laminating direction, on the failure modes observed after the small punch tensile test.

Bioengineered skeletal muscle constructs that replicate the architectural, metabolic, and contractile characteristics of native tissue are becoming essential platforms for disease modeling and advancing regenerative medicine. The creation of these constructs relies heavily on cell-mediated gel compaction, a crucial process for facilitating tissue maturation. To ensure myotube alignment, muscle cell-laden hydrogels are typically embedded in 3D-printed molds with anchor structures. However, structural detachment or rupture often occurs during culture, which undermines the stability and functional differentiation of the engineered tissue. To address these challenges, we developed an improved anchor-type mold through a series of structural optimizations. We first compared two anchor geometries—linear and mushroom-shaped pillars—within rectangular frames, finding that the mushroom-shaped design provided better structural retention. However, the rectangular frames led to excessive gel compaction, causing detachment and disrupting cellular alignment, especially in central regions. To alleviate these issues, we introduced a dumbbell-shaped mold with a narrowed midsection to better distribute mechanical stress. This new mold effectively promoted aligned myotube formation, long-term construct maintenance, and functional maturation. Our findings underscore the benefits of structurally optimized molds in creating stable engineered muscle, with significant implications for regenerative therapies and preclinical testing platforms.

Microphysiological systems (MPS) are advanced platforms that mimic the functions of human tissues and organs, aiding in drug development and disease modeling. Traditional MPS fabrication mainly depends on silicon-based microfabrication techniques, which are complex, time-consuming, and costly. In contrast, 3D printing technologies have emerged as a promising alternative, allowing for the rapid and precise creation of intricate three-dimensional structures, thereby opening new avenues for MPS research. This review examines the principles, characteristics, advantages, and limitations of key 3D printing techniques, including fused deposition modeling (FDM), stereolithography (SLA)/digital light processing (DLP), inkjet 3D printing, extrusion-based bioprinting, and laser-assisted bioprinting. Additionally, we discuss how these technologies are applied in MPS fabrication and their impact on MPS research, along with future prospects for advancements in the field.