Structural Behavior of a Composite Curtain Wall Fabricated by the Fused Deposition Modeling 3D Printing Method.

In this era of the fourth industrial revolution, the integration of big data and 3D printing technology with the construction industry has maximized productivity. Currently, there is an active effort to research the optimal cladding structure through 3D printing technology to reduce production costs. This paper proposes a new type of 3D print curtain wall, using a high-strength ABS-M30 polymer panel, which is stronger than the standard acrylonitrile butadiene styrene (ABS) polymer, as an internally reinforced structure. This structure is fabricated via fused deposition modeling, a 3D printing method, to reduce the weight of the general cement panel. In addition, the shape of the polymer board was designed; three shapes were considered-O, W, and X types-which aided in further reducing the weight of the cladding. After comparing the center deformation of the structure through a lateral load test and finite element method analysis, the optimal model was selected. The measured data of the two methods at a design wind speed of 100% showed a difference of approximately 10%; however, at 150% of the design wind speed, the difference between the two sets of data increased to 27%.

The Development of Biomimetic Aligned Skeletal Muscles in a Fully 3D Printed Microfluidic Device.

Human skeletal muscles are characterized by a unique aligned microstructure of myotubes which is important for their function as well as for their homeostasis. Thus, the recapitulation of the aligned microstructure of skeletal muscles is crucial for the construction of an advanced biomimetic model aimed at drug development applications. Here, we have developed a 3D printed micropatterned microfluid device (3D-PMMD) through the employment of a fused deposition modeling (FDM)-based 3D printer and clear filaments made of biocompatible polyethylene terephthalate glycol (PETG). We could fabricate micropatterns through the adjustment of the printing deposition heights of PETG filaments, leading to the generation of aligned half-cylinder-shaped micropatterns in a dimension range from 100 µm to 400 µm in width and from 60 µm to 150 µm in height, respectively. Moreover, we could grow and expand C2C12 mouse myoblast cells on 3D-PMMD where cells could differentiate into aligned bundles of myotubes with respect to the dimension of each micropattern. Furthermore, our platform was applicable with the electrical pulses stimulus (EPS) modality where we noticed an improvement in myotubes maturation under the EPS conditions, indicating the potential use of the 3D-PMMD for biological experiments as well as for myogenic drug development applications in the future.

DICOM segmentation and STL creation for 3D printing: a process and software package comparison for osseous anatomy.

BACKGROUND: Extracting and three-dimensional (3D) printing an organ in a region of interest in DICOM images typically calls for segmentation as a first step in support of 3D printing. The DICOM images are not exported to STL data immediately, but segmentation masks are exported to STL models. After primary and secondary processing, including noise removal and hole correction, the STL data can be 3D printed. The quality of the 3D model is directly related to the quality of the STL data. This study focuses and reports on the DICOM to STL segmentation performance for nine software packages. METHODS: Multidetector row CT scanning was performed on a dry human mandible with two 10-mm-diameter bearing balls as a phantom. The DICOM image file was then segmented and exported to an STL file using nine different commercial/open-source software packages. Once the STL models were created, the data (file) properties and the size and volume of each file were measured, and differences across the software packages were noted. Additionally, to evaluate differences between the shapes of the STL models by software package, each pair of STL models was superimposed, with the observed differences between their shapes characterized as the shape error. RESULTS: The data (file) size of the STL file and the number of triangles that constitute each STL model were different across all software packages, but no statistically significant differences were found across software packages. The created ball STL model expanded in the X-, Y-, and Z-axis directions, with the length in the Z-axis direction (body axis direction) being slightly longer than that in the other directions. The mean shape error between software packages of the mandibular STL model was 0.11 mm, but there was no statistically significant difference between them. CONCLUSIONS: Our results revealed that there are some differences between the software packages that perform the segmentation and STL creation of the DICOM image data. In particular, the features of each software package appeared in the fine and thin areas of the osseous structures. When using these software packages, it is necessary to understand the characteristics of each.

Utilizing a low-cost desktop 3D printer to develop a "one-stop 3D printing lab" for oral and maxillofacial surgery and dentistry fields.

BACKGROUND: In the oral and maxillofacial surgery and dentistry fields, the use of three-dimensional (3D) patient-specific organ models is increasing, which has increased the cost of obtaining them. We developed an environment in our facility in which we can design, fabricate, and use 3D models called the "One-stop 3D printing lab". The lab made it possible to quickly and inexpensively produce the 3D models that are indispensable for oral and maxillofacial surgery. We report our 3D model fabrication environment after determining the dimensional accuracy of the models with different laminating pitches (; layer thickness) after fabricating over 300 3D models. Considerations were made for further reducing modeling cost and model print time. MDCT imaging was performed using a dry human mandible, and 3D CAD data were generated from the DICOM image data. 3D models were fabricated with a fused deposition modeling (FDM) 3D printer MF-2000 (MUTOH) with a laminating pitch of 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. Each 3D model was then subjected to reverse scanning to evaluate the modeling conditions and deformation during modeling. For the 3D image processing system, Volume Extractor 3.0 (i-Plants Systems) and POLYGONALmeister V2 (UEL) were used. For the comparative evaluation of CAD data, spGauge 2014.1 (Armonicos) was used. RESULTS: As the laminating pitch increased, the weight of the 3D model, model print time, and material cost decreased, and no significant reduction in geometric accuracy was observed. CONCLUSIONS: The amount of modeling material used and preparation cost were reduced by increasing the laminating pitch. The "One-stop 3D printing lab" made it possible to produce 3D models daily. The use of 3D models in the oral and maxillofacial surgery and dentistry fields will likely increase, and we expect that low-cost FDM 3D printers that can produce low-cost 3D models will play a significant role.