3D Printing System Research Articles

Budesonide –Oral Galenic Formulations for Chron Disease

Aim of this work is to verify the farmaceutical form of oral Budesonide compounded used in Chron’s disease: capsules delay release or oral suspension. In particular way the kinds of excipients or bases-veicle used in the galenic pharmacy. The therapeutic need require a release of the API in delayed release. The Budesonide show low systemic impacts due by its hepatic methabolism vs a tocipal effect useful in this pathology. Some formulation provided by various pharmacy are reported as well as new technology like the 3D-PRINTING systems for colonic targeting tablets.

Low-cost fabrication of digital light processing 3D printed conical microneedles for biomedical applications

The 3D printing of microneedles has become an emerging area of research focus due to its ability to rapidly create microneedle arrays with parametrically variable geometry and composition. Through direct fabrication or via replica molding, 3D printed microneedles can facilitate iterative array assessment and act as a screening tool to quickly establish optimal parameters for tissue insertion and capacity for biomarker monitoring or drug release. However, the widespread adoption of 3D printing by microneedle array researcher group faces multiple barriers: (1) Investment in 3D printing systems that are traditionally associated with high-resolution pose a significant financial cost, (2) Current high-resolution printing methods are often slow and not conducive to rapid manufacturing, (3) Material selection can be limited in some ‘proprietary’ 3D printing systems (e.g. CLIP, SLA, or 2PP), (4) Given the multidisciplinary nature of the microneedle-field, researchers may not have the expertise to optimize printing parameters for a given material or printer. This work explores how ultra-low-cost digital light processing (DLP) printers can rapidly produce functional microneedle arrays for a variety of purposes, whether direct print, master mold production, or creation of coated microneedles, at a fraction of the cost of currently used systems. Further, this work highlights that high quality microneedle arrays can be created using DLP printing methods with reliability exceeding 98 %, tip radii on the order of 30 µm, and with appropriate parameter input optimization, high quality microneedle arrays can be fabricated that express desirable characteristics for multiple forms of solid microneedle array production.

3D Micropatterning With Thermochromic Polymer Microfiber

AbstractAlthough 3D micropattern has received considerable attention due to their remarkable usability, the introduction of specific functions, such as “chromism”, is still a challenge mainly due to the lack of adequate functional materials that can be introduced into 3D printing system. In this study, 3D micropatterns with temperature‐responsive properties are created by elaborately aligned thermochromic polymer microfibers using charge reversal electro‐jet writing (CREW) method with a 3D printer. A reversible color change in response to the temperature change is exhibited in the micropattern, displaying various chromic colors, such as red, blue, and black, at their own thermochromic temperatures. Multiple‐color phases can be sequentially expressed in a single structure by incorporating pigments of different colors with distinguishable color shift ranges. Various patterning methods are proposed for manufacturing diverse patterns and demonstrating applications using combinations of color. In addition to directly increasing temperature, the thermochromic process of micropatterns can be induced by heat generated from external factors using electrical energy. These 3D thermochromic micropatterns using the CREW method can be extended to various fields, including sensors, clothing, and anti‐counterfeiting.

Influence of 3D printing system, postpolymerization and aging protocols on resin flexural strength and dimensional stability for printing occlusal splints, models and temporary restorations.

Investigate the effect of different postpolymerization protocols, aging, and 3D printing systems on the flexural strength (σ), dimensional stability, and roughness of resins used to fabricate occlusal splints, dental models, and temporary restorations. 180 bars (25 × 2 x 2mm-ISO 4049) of each type of resin (T-Temporary/Cosmos Temp, Yller; OS-Occlusal splint/Cosmos Splint, Yller; MO - Models/ Cosmos Model, Yller) were printed and divided into 12 groups (n = 15) according to the factors: "Postpolymerization" (Ctr - Control; UV - Ultraviolet oven and MW - Microwave); "Printer" (SLA- stereolithography (Forms 2/Formslab); LCD- liquid crystal display (FlashForge Foto 6.0/FlashForge)) and "Aging" (TC - 10,000 thermocycling cycles and Without). Each bar was measured with a digital caliper at 11 points before and after postpolymerization to evaluate dimensional stability. The samples were subjected to the σ test (100Kgf;1mm/min). Data was evaluated using Three- and Two-way ANOVA, and Tukey's test (5%). Weibull analysis, Scanning Electron Microscopic and optical profilometry was performed. LCD printing system and UV oven postpolymerization exhibited the highest σ (P < .05). The groups printed in SLA and post-polymerized in microwave ovens showed the greatest variations in their dimensions, for the occlusal splint resin, the OS-SLA-MW group (-4.29 ± 3.15)A showed a shrinkage of 40.2%. The resins for models (3.31 ± 0.66)A and temporary (-2.06 ± 1.52)A showed a shrinkage of 33% and 20.6%, respectively. LCD printing with UV light postpolymerization was the most effective method for resins used in occlusal splints, dental models, and temporary restorations. SLA printing with UV postpolymerization showed the most significant dimensional changes, leading to shrinkage in occlusal splint resins, while model resins and temporary restorations expanded. Resins for 3D printing should ideally be post-polymerized with UV light and printed using LCD technology, as this approach results in better mechanical properties and less dimensional change compared to microwave oven post-polymerization.

Budesonide – Oral Galenic Formulations for Crohn Disease

The aim of this work is to verify the pharmaceutical form in the galenic field of oral Budesonide compounded used in Crohn’s disease: capsules delay release or oral suspension. In particular ways the kinds of excipients or bases-vehicle used in the galenic pharmacy practice. The therapeutic need for Crohn’s disease requires a release of the API in delayed-release DR. The Budesonide molecule shows low systemic impacts due to its hepatic metabolism vs. a topical effect useful in this pathology. In this work, the oral pharmaceutical forms are analyzed: modified-release capsules and oral suspension with specific advantages for each one. Some formulations provided by various pharmacies are reported in this work as well as new technology like the 3D-PRINTING systems for colonic targeting tablets.

Intaglio surface of CNC milled versus 3D printed maxillary complete denture bases – An in vitro investigation of the accuracy of seven systems

ObjectivesThe accuracy of the intaglio surface of maxillary complete dentures produced with a variety of digital manufacturing systems have been comprehensively investigated, however, not for multiple systems in the same study. This in vitro study endeavors to measure and compare the accuracy of the intaglio surface of maxillary complete denture bases constructed with different photopolymerization-based 3D printing and CNC milling systems. Materials and MethodsTwo subtractive manufacturing machines and five additive manufacturing machines were used to manufacture a maxillary denture bases (n = 10) for analysis. The samples were stored in artificial saliva at 37 °C for 7 days to mimic intraoral use before they were air dried for 5 min, and then scanned with an E3 dental laboratory scanner to generate STL files. A 3D metrology software program was used to analyze the data against the original CAD design. Statistical differences were determined with 1-way analysis of variance (ANOVA) and the Kruskal Wallis test (α=0.05). Color deviation heat maps were used to interpret areas of clinical significance. ResultsThe results indicated that the subtractive manufacturing method delivers the truest and most precise intaglio surface of maxillary complete denture bases. The additive manufacturing technique delivers less true and less precise results with inconsistency observed between the different systems as opposed to the subtractive manufacturing groups which showed no significant differences. ConclusionsWhen manufacturing a complete maxillary denture base subtractive manufacturing will deliver the most consistent and true results.

The Mechanical and Clinical Properties of Customized Orthodontic Bracket Systems-A Comprehensive Review.

The rise of computer-aided design and computer-aided manufacturing (CAD/CAM) and 3D printing technologies in orthodontics has revolutionized the development of customized labial and lingual bracket systems with a variety of materials, which offer potential advantages over traditional orthodontic brackets. To highlight the current state of knowledge regarding the mechanical and clinical properties of CAD/CAM and 3D-printed custom bracket systems, we conducted a comprehensive search across the PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases to identify relevant articles published before April 2024. Mechanical (including fracture toughness, hardness, modulus of elasticity, frictional resistance, slot accuracy, torque transmission, and shear bond strength) and clinical (including treatment efficiency and duration, cost, and comfort) properties were compared between traditional and customized orthodontic bracket systems in the current review. Our findings suggest that customized brackets have the potential to increase bracket slot precision, reduce treatment time, and offer cost-efficiency. However, it is worth noting that the advantages and disadvantages of customized bracket systems vary depending on the bracket material and the manufacturing methods, warranting comprehensively controlled investigations in the future.

A novel compact xerographic system for 3D printing of fluoropolymer powders onto metal surfaces

Abstract This study introduces a compact xerographic 3D printing system that utilizes precise layer-by-layer dry powder transfer techniques, facilitating the fabrication of 3D objects directly on metal substrates. By leveraging electrostatic force to coat dry fluoroethylene vinyl ether powder onto metallic surfaces, our innovative method significantly broadens the spectrum of printable materials. Through the optimization of electrostatic potentials and powder transfer efficiency, the system successfully demonstrates the ability to produce intricate 3D structures with heights ranging from millimeters to centimeters. This novel approach not only showcases the potential for creating flexible electronic materials with complex 3D geometries directly on the metal substrate but also opens new avenues for diverse material applications within the field of advanced xerographic 3D printing technology.

Flexural strength, fracture toughness, translucency, stain resistance, and water sorption of 3D-printed, milled, and conventional denture base materials.

To compare mechanical, optical, and physical properties of denture base materials fabricated with various 3D printing systems to reference milled and conventionally heat-processed denture base materials. Specimens of denture base materials were either 3D-printed (DLP in-office printer, CLIP laboratory printer, or material jetting laboratory printer), milled, or heat processed. 3-point bend flexural strength testing was performed after 50 hours of water storage following 1hour of drying (dry testing) or in 37°C water (wet testing). Fracture toughness was performed with a notched beam specimen after 7 days of water storage and tested dry. The translucency parameter was measured with 2mm thick specimens. Stain resistance was measured as color change following 14 days of storage in 37°C coffee. Water sorption was measured following 7 days of storage in 37°C distilled water. For dry testing, all but one of the 3D-printed materials attained higher or equivalent flexural strength as the reference materials. For wet testing, all 3D-printed materials attained higher or equivalent strength as the reference materials and dry-tested materials. For 3D-printed materials, wet testing increased displacement before fracture whereas it decreased displacement for the reference materials. Only two of the 3D-printed materials had similar fracture toughness as the reference materials. One of the 3D-printed materials was more translucent and one was more opaque than the reference materials. Only one of the 3D-printed materials absorbed more water than the reference materials. 3D-printed denture base materials have mostly equivalent mechanical, optical, and physical properties to conventional and milled denture base materials.

Fractal-fractional model for the receptor in a 3D printing system

A critical hurdle in three-dimensional printing is the low printing accuracy. In particular, the deformation of the printed object on the receptor makes accurate printing impossible due to insufficient solvent evaporation. We address this challenge by establishing a Murray-like receptor to control the morphology of the printed object, which can be used for accurate printing through efficient residual energy absorption and active vibration attenuation. A fractal oscillator is established and He’s frequency formulation is used to reveal the fractal response of the Murray-like receptor, and an experiment was carried out to show that the receptor system can keep the printed object in good shape without any deformation.

Tuning the Mechanical Properties of 3D-Printed Objects by Mixing Chain Transfer Agents in Norrish Type I Photoinitiated RAFT Polymerization.

Photoinduced 3D printing via photocontrolled reversible-deactivation radical polymerization (photoRDRP) techniques has emerged as a robust technique for creating polymeric materials. However, methods for precisely adjusting the mechanical properties of these materials remain limited. In this study, we present a facile approach for adjusting the mechanical properties of 3D-printed objects by adjusting the polymer dispersity within a Norrish type I photoinitiated reversible addition-fragmentation chain transfer (NTI-RAFT) polymerization-based 3D printing process. We investigated the effects of varying the concentrations and molar ratios of trithiocarbonate (BTPA) and xanthate (EXEP) on the mechanical properties of the printed materials. Our findings demonstrate that increased concentrations of RAFT agents or higher proportions of the more active BTPA lead to a decrease in Young's modulus and glass transition temperatures, along with an increase in elongation at break, which can be attributed to the enhanced homogeneity of the polymer network. Using a commercial LCD printer, the NTI-RAFT-based 3D printing system effectively produced materials with tailored mechanical properties, highlighting its potential for practical applications.

Design of a Robotic 3D Printing System

Abstract Additive manufacturing enables the production of complex shapes with a large degree of freedom compared to conventional manufacturing techniques such as injection molding, thermoforming or pressing. In particular, the creation of moving parts, complex structures and large-scale printing remains underexplored and research is constantly expanding. Due to design limitations related to the construction of currently available printers, 3D printing technology is increasingly being combined with robotics. Using a robot to 3D print products eliminates the need to design complex printer structures, which ultimately should simplify the process of manufacturing large-scale products and shorten the time required for preparation and production. The paper deals with the description of the designed 3D printing system and the procedure of the steps of creating a robotic simulation model with the generation of a control program for the FDM 3D printing process by an industrial robot.

Physics-based approach to developing physical reservoir computers

Reservoir computing leverages the dynamic properties of a fixed, randomly connected neural network to facilitate simplified training and enhanced computational efficiency. Many forms of physical reservoir computers have been proposed. In this paper, we use a three-dimensional (3D)-printed reservoir computer as the design environment, develop analytic models to describe its performance, and validate the models through simulations. This approach offers practical insights for designing physical reservoirs with targeted computational capabilities and enables the assessment of the influence of reservoir parameters such as scale or material choice, on performance metrics, including speed and power consumption. Additionally, the proposed approach may be employed to optimally design physical reservoir computers to solve specific problems. This work contributes to the understanding of physical RC systems by providing a detailed analysis of the physical basis that connects computational performance with multidomain physical interactions at the device level. The methods and results from this work not only propel the development of future 3D-printed physical RC systems but also serves as a framework for evaluating and designing diverse physical RC models based on other approaches. Published by the American Physical Society 2024

3D printing and intelligent technology increase convenience, reliability, and patient acceptance of ostomy nursing: a randomized controlled trial.

Traditional ostomy bags commonly cause skin allergy and inflammation around the stoma, as well as leakage. This study aimed to examine the effect of a 3D-printed ostomy bag with sensors and stimulators on stoma nursing. This is a randomized controlled trial. This trial involved 113 distinct individuals who undergo colorectal cancer surgery and intestinal obstruction surgery, with resulting stoma. The date of trial registration was January 17, 2019, and the date of first recruitment was May 1, 2019. Patients were randomized into two groups: intelligent 3D-printed ostomy bag (3D group, n = 57) and Coloplast one-piece pouching systems (control group, n = 56). The shape of ostomy and the surrounding skin of all the 57 patients of the 3D group was scanned by a handheld 3D scanner. Then, the ostomy bag chassis (also known as skin barrier) was 3D printed and an intelligent device adhered to the ostomy bag. The wearing time, leakage rate, the Discoloration, Erosion, and Tissue Overgrowth (DET) score, and the Acceptance of Illness Scale (AIS) were observed. In the 3D-printed bag group, the time to wear (0.7 ± 0.4m) was significantly shorter than that of the control group (9.1 ± 3.5m). The leakage rate of 3D-printed bag (1.75%) was significantly lower than that of the control group (16.1%). The DET score for the 3D-printed bag group was also lower than that of the control group, and the AIS score for the 3D-printed bag group was higher than that of the control group. The 3D-printed ostomy bags and the linked computer program can significantly reduce wearing time, leakage rate, and stoma complications. This may improve the quality of home ostomy care for patients and reduce the incidence of skin complications around the stoma.Registration number: ChiCTR1900020752.

Scanning‐Laser‐Based Microstereolithography of Microfluidic Chips with Micron Resolution

AbstractThe constant improvement of stereolithography (SL) in terms of achievable resolution and printing time has sparked high expectations that SL will enable the rapid prototyping of truly microfluidic chips with features below 100 µm. However, most commercial high‐resolution stereolithography devices are based on Digital Light Processing (DLP) and thus sacrifice lateral printing size for resolution. Consequently, even 10 years after the advent of microstereolithography there is no commercialized 3D printing system that can effectively fulfill all the demands to replace soft lithography for microfluidic prototyping. In this work, for the first time, This study demonstrates that a commercial laser‐based stereolithography device is capable of manufacturing microfluidic chips with embedded channels smaller than 100 µm with a footprint of 7.24 × 0.3 cm2. A chip fabricated in poly(ethylene glycol) diacrylate (PEGDA) that can readily be used for fluid mixing, is presented in this study. This research shows that the accessibility of high‐resolution chips with footprints of several cm2, using laser‐based stereolithography, enables the manufacturing of truly microfluidic systems with high impact on prototyping and manufacturing.

Operando Colorations from Real-Time Growth of 3D-Printed Nanoarchitectures.

While artificial 3D nanostructures can generate precise and flexible coloration, their real-time color changes during 3D nanoprinting remain unexplored owingto the inherent challenges of in situ transient measurements and observations. In this study, a 3D-printing system which supports the operando observation/measurement of the color dynamics of subwavelength metallic nanoarchitectures fabricated in real time is developed and evaluated. During 3D printing, the dimensions and geometries of the 3D nanostructures grow over time, producing a large library of optical spectra associated with real-time color changes. Only a timer is needed to define the expected colors from a single 3D print run. Fin-like nanostructures are used to toggle colors based on the polarization effect and produce color gradients. Based on structural coloration, nanoarchitectures are designed and printed to animate desired color patterns. Moreover, the resulting color dynamics can also serve as an operando identifier for real-time structural information during 3D nanoprinting. A single print run enables the efficient creation of a comprehensive library of desired colorations owing to the flexibility in time-dependent controllability and 3D geometries at the subwavelength scale. 3D nanoprinted plasmonic structures exhibiting time-varying colorations (4D printing of colors) uniquely redefines the coloring stategy,offering considerable potential for numerousapplications.

3D Printing Systems Designed for the Factory Floor

Markforged is enabling more resilient and flexible supply chains with its 3D printers by bringing industrial production to the point of need. We caught up with Daniel Leong, senior product manager, to hear more

Efficacy of virtual surgical planning and a three-dimensional-printed, patient-specific reduction system to facilitate alignment of diaphyseal tibial fractures stabilized by minimally invasive plate osteosynthesis in dogs: A prospective clinical study.

To evaluate the efficacy of a three-dimensional (3D)-printed, patient-specific reduction system for aligning diaphyseal tibial fractures stabilized using minimally invasive plate osteosynthesis (MIPO). Prospective clinical trial. Fifteen client owned dogs. Virtual 3D models of both pelvic limbs were created. Pin guides were designed to conform to the proximal and distal tibia. A reduction bridge was designed to align the pin guides based on the guides' spatial location. Guides were 3D printed, sterilized, and applied, in conjunction with transient application of a circular fixator, to facilitate indirect fracture realignment before plate application. Alignment of the stabilized tibiae was assessed using postoperative computed tomography scans. Mean duration required for virtual planning was 2.5 h and a mean of 50.7 h elapsed between presentation and surgery. Guide placement was accurate with minor median discrepancies in translation and frontal, sagittal, and axial plane positioning of 2.9 mm, 3.6°, 2.7°, and 6.8°, respectively. Application of the reduction system restored mean tibial length and frontal, sagittal, and axial alignment within 1.7 mm, 1.9°, 1.7°, and 4.5°, respectively, of the contralateral tibia. Design and fabrication of a 3D-printed, patient-specific fracture reduction system is feasible in a relevant clinical timeline. Intraoperative pin-guide placement was reasonably accurate with minor discrepancies compared to the virtual plan. Custom 3D-printed reduction system application facilitated near-anatomic or acceptable fracture reduction in all dogs. Virtual planning and fabrication of a 3D-printing patient-specific fracture reduction system is practical and facilitated acceptable, if not near-anatomic, fracture alignment during MIPO.

Electrowriting of SU-8 Microfibers.

As microfiber-based additive manufacturing (AM) technologies, melt electrowriting (MEW) and solution electrowriting (SEW) have demonstrated efficacy with more biomedically relevant materials. By processing SU-8 resin using MEW and SEW techniques, a material with substantially different mechanical, thermal, and optical properties than that typically processed is introduced. SU-8 polymer is temperature sensitive and requires the devising of a specific heating protocol to be properly processed. Smooth-surfaced microfibers resulted from MEW of SU8 for a short period (from 30 to 90 min), which provides the greatest control and, thus, reproducibility of the printed microfibers. This investigation explores various parameters influencing the electrowriting process, printing conditions, and post-processing to optimize the fabrication of intricate 3D structures. This work demonstrates the controlled generation of straight filaments and complex multi-layered architectures, which were characterized by brightfield, darkfield, and scanning electron microscopy (SEM). This research opens new avenues for the design and development of 3D-printed photonic systems by leveraging the properties of SU-8 after both MEW and SEW processing.

DEVELOPMENT OF A ROBOTIC FABRICATION SYSTEM FOR CEMENTITIOUS MATERIALS

Our team at Klokner Institute under Czech Technical University in Prague is working in a joint effort with Technical University of Liberec and Klokner on a comprehensive 3D printing system for cementitious materials, including specially optimized robotic arm. The goal of this system is to decrease the environmental impact of construction industry by reducing the volume of materials and time required, as well as reducing need for human labor. 3D printing also makes possible to build complex functional shapes, that would be too complicated or prohibitively expensive to manufacture using standard industry methods. Combining expertise of these two institutions lead to development of a robust system, that seamlessly integrates in-house developed mechanics and print material. One of key areas of our research is also testing mechanical properties of printed parts which is essential to safely integrate this construction method in real-world use in the future.