In the era of artificial intelligence (AI), materials with soft and strong properties are becoming increasingly important. Various three‐dimensional (3D) fused deposition modeling (FDM) filaments have been developed as soft actuator materials. In the present study, a soft actuator‐grade thermoplastic polyurethane (TPU) was developed and then processed into a filament for FDM 3D printers during a melt‐extrusion process using commercial (65, 75, 80, and 85 Shore A) pellets. Rheological, chemical, thermal, and mechanical properties of the manufactured TPU filaments were characterized. Auxetic re‐entrant TPU samples were then printed with the manufactured filament. Results showed that the 75 Shore A pellet was the most suitable for auxetic re‐entrant FDM 3D printing.

In this study, bio-based thermoplastic polyurethane (TPU) for use in soft actuators is bio-based poly(ether-urethane) made using fermented corn, along with bio-derived compounds such as propane-1,3-diol (PDO) as a chain extender. Bio-based TPUs were obtained through a solvent-free one-shot synthesis method, and the effects of varying the [NCO]/[OH] molar ratio and type of isocyanates on chemical structure, thermal stability, and mechanical properties were investigated. The degree of phase separation (DPS) and state of hard segment (HS) / soft segment (SS) of TPU are important factors affecting the thermal and physical properties of the prepared film. These properties depend on the [NCO]/[OH] molar ratio and the type of isocyanates used for polymerization. The results showed that, when aromatic isocyanate was used, the degree of separation of the HS/SS was improved as the molar ratio increased. The average molecular weight and DPS as well as thermal and mechanical properties of 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene (MDI)-based TPU samples are all higher than those of 1,1’-methylenebis(4-isocyanatocyclohexane) (H12MDI)-based TPU samples in spite of the lower HS content. These findings of this study are expected to contribute to the preparation of fused deposition modeling (FDM) 3D printing or 4D printing for shape memory polymer from bio-based TPU filaments for use in soft actuators with a shore hardness range of 59~84A.

This study describes a soft-actuator grade thermoplastic polyurethane (TPU) with 73 $ 86 shore A, the method of its fabrication and selected properties.The TPU was produced using bio-based synthesized TPU (HP 2.5, HP 3.0, HB 2.5, and HB 3.0) pellets with bio-based polyether-biol (PO3G-1000), and dicyclohexylmethane diisocyanate (H 12 MDI) and bio-based 1,3 propanediol (PDO) and 1,4 butanediol (BDO) as a chain extender. The TPU was formed into a filament for fused deposition modeling (FDM) 3D printers during a melt-extrusion process at 180 $ 220 C. The manufactured TPU filaments were characterized by rheological, chemical, thermal, and mechanical analyses. The equivalence ratio 3.0 with a relatively large amount of HS with BDO as a chain extender, more hydrogen-bonding peaks occurred. The transition temperature and mechanical properties increased depending on the [NCO]:[OH] ratio, and for BDO as the chain extender. However, it was found that when PDO derived from natural material was used, the thermal stability was better. From these results, samples of auxetic re-entrant TPU were printed with the filaments with reference to the melt flow index. The results showed that the biosynthesized HP 3.0 with a hardness of (82 ± 1) shore A was most suitable for FDM 3D printing.

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The purpose of this study was to evaluate the effects of using standardized patients on nursing competence, communication skills, and learning satisfaction in health assessment. Method: This study was a nonequivalent control group non-synchronized post-test design. Study participants were recruited from third-year nursing students at a university. The data were analyzed using the SPSS/WIN 18.0 program. Results: The mean scores of nursing competence and communication skills were significantly higher in the experimental group than the control group. However, the two groups were not statistically different in learning satisfaction. Conclusion: The findings suggest that the use of standardized patients compared to the traditional method is an effective educational method for health assessment in nursing competence and communication skills. Therefore, it is necessary to develop various scenarios and apply standardized patients for health assessment. In addition, further research is required to evaluate its effects.