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The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories.

Recent patents relating to systems, methods and compositions for bioprinting.

Introduction Mandibular advancement devices (MAD) for obstructive sleep apnea have traditionally been a prohibitive therapy for a large number of patients due to high out-of-pocket expense and access to dentistry. This study examined if an increasingly more accessible and user-friendly technology, 3D printing, may provide a cost-effective in-office workflow to increase access to MAD use. Methods Available pricing data was sourced via PubMed articles searching keywords “oral appliance”, “sleep apnea”, “mad” and “cost”. Additional price point data was compiled from publicly available information from the largest dental insurance provider in the United States, Delta Dental. Computer Aided Design (CAD) software Fusion360 was used to prototype a MAD and Stereolithography (SLA) printing using FormLab’s 3B+ printer was performed by a University-run 3D printing lab. Results Traditional cost per MAD ranges from 400USD – 2,450USD with a mean of 933USD (based on the only available 1997 pricing data). The total cost of the one-off MAD used in this study was 150USD (consumable cost of 2.66USD, labor cost of 147.34USD). This excluded the one-time 3D printer cost of 3,750USD. At 1 device printed per day over 1 year, total cost per printed device would be estimated at $22, which is 5% of the traditional cost of MAD. Total print time is estimated at 54 minutes, post processing time is estimated at 25 minutes, with a total MAD delivery to patient time of 1.3 hours. Conclusion Point-of-care 3D printed oral appliances are a feasible and inexpensive workflow to expand the use of MADs in the treatment of mild to moderate sleep apnea. Multiple barriers remain in integrating this workflow into patient care, including integration with dentistry. Support (if any)

Introduction: the article discusses the legal aspect of 3D printing and computer 3D models, which are printed using a 3D printer. The prospects, threats and challenges that the development of 3D printing technologies entails are examined. The author comes to the conclusion that it is necessary to adapt the new technological realities to the current legislation and it is necessary to take into account which particular object will be displayed in the three-dimensional model, since this will determine which rights to objects will be affected. Methods: the methodological basis of this scientific article is a number of methods of scientific knowledge, among which the main place is occupied by methods of information processing and logical analysis, synthesis, induction, deduction and generalization. Results: the author’s position on 3D models and their legal regulation is presented. Conclusions: as a result of the study, recommendations were made for improving the regulatory framework, the author proposes to delimit the legal protection of 3D models by amending Art. 1259, 1352 of the Civil Code of the Russian Federation.

Architected materials that control elastic wave propagation are essential in vibration mitigation and sound attenuation. Phononic crystals and acoustic metamaterials use band-gap engineering to forbid certain frequencies from propagating through a material. However, existing solutions are limited in the low-frequency regimes and in their bandwidth of operation because they require impractical sizes and masses. Here, we present a class of materials (labeled elastic metastructures) that supports the formation of wide and low-frequency band gaps, while simultaneously reducing their global mass. To achieve these properties, the metastructures combine local resonances with structural modes of a periodic architected lattice. Whereas the band gaps in these metastructures are induced by Bragg scattering mechanisms, their key feature is that the band-gap size and frequency range can be controlled and broadened through local resonances, which are linked to changes in the lattice geometry. We demonstrate these principles experimentally, using advanced additive manufacturing methods, and inform our designs using finite-element simulations. This design strategy has a broad range of applications, including control of structural vibrations, noise, and shock mitigation.

Research Type: Level 4 – Case series Introduction/Purpose: The complex, three-dimensional nature of Progressive collapsing foot deformity (PCFD) makes it difficult to grasp using conventional imaging displays. The new PCFD classification system categorizes deformities into Class A (hindfoot valgus), Class B (midfoot/forefoot abduction), Class C (forefoot varus/medial column instability), Class D (peritalar subluxation), and Class E (valgus talar tilt). Emerging technologies such as Weightbearing CT (WBCT) based 3D printing of patient-specific anatomical models may have the potential to enhance diagnostics by providing improved 3D visualization and a tactile experience. This study aimed to evaluate the inter- and intraobserver reliability of orthopedic foot and ankle surgeons in identifying each PCFD class relying solely on anatomical 3D-printed foot models. Methods: Sixty patients (37 female, 23 male; mean age 53 ±17.2 years) who underwent surgical correction of PCFD by a single surgeon were included. Preoperative weightbearing CT (WBCT) scans were semiautomatically segmented, and a 3D reconstruction (as stereolithography model) of each foot was created with linking bars between bones, and subsequently 3D-printed. Five fellowship-trained foot and ankle surgeons independently assessed the models, blinded to clinical data. Without conducting measurements, they identified the presence or absence of PCFD classes A to E solely based on experience and visual-tactile analysis. Staging between flexible and rigid PCFD was not performed due to the presence of connecting bars. After several weeks, the assessments were repeated for a second reading. Percentage agreement within and between readers was calculated, and intra- and interobserver reliability for each PCFD class was evaluated using Cohen’s kappa and Fleiss’ kappa, respectively. Results: Intrarater reliability varied across PCFD classes. Class A showed perfect agreement (Cohen’s Kappa = 1.00). Other classes had moderate reliability, with Class D being the highest (Kappa = 0.66) and Class B the lowest (Kappa = 0.40). Agreement ranged widely, with Class A showing the highest consistency (96.7% - 100%) and Class E the lowest (75% - 91.7%). Inter-rater reliability also varied. Class A had perfect agreement (100%), making Fleiss’ Kappa undefined. The remaining classes had poor to fair agreement, with Class B showing the lowest reliability (75.7%, Kappa = 0.1). The most frequently observed class combinations were ABCD (30%), ABC (23%), and ABCDE (19%), while Class A (99.7%) and Class C (86.2%) were the most frequently described single classes. Conclusion: This study highlighted the potential of 3D printing for classifying PCFD cases. Inter- and intraobserver reliability varied across classes, with limitations in identifying all deformities solely from 3D-printed models without the WBCT images – an issue not present in the clinical setting. While Class A exhibited perfect agreement, Class B had the lowest kappa values, but still achieved intra- and interrater percent agreements of 91.7% and 75.7%, respectively. 3D printing may serve as a valuable supplement for diagnostics and treatment planning, but further research is needed to determine which model-specific factors influence readers' decisions compared to multiplanar WBCT imaging.

Additive manufacturing (3D printing) has significantly changed the prototyping process in terms of technology, construction, materials, and their multiphysical properties. Among the most popular 3D printing techniques is vat photopolymerization, in which ultraviolet (UV) light is deployed to form chains between molecules of liquid light-curable resin, crosslink them, and as a result, solidify the resin. In this manuscript, three photopolymerization technologies, namely, stereolithography (SLA), digital light processing (DLP), and continuous digital light processing (CDLP), are reviewed. Additionally, the after-cured mechanical properties of light-curable resin materials are listed, along with a number of case studies showing their applications in practice. The manuscript aims at providing an overview and future trend of the photopolymerization technology to inspire the readers to engage in further research in this field, especially regarding developing new materials and mathematical models for microrods and bionic structures.

This study proposes an optimization strategy to analyze the trade-off between the conflicting objectives of minimizing energy use in 3D printing by fused deposition modeling. The motivation for this work is the need to optimize natural resources, finite in nature, in a more competitive industrial reality and increasingly focused on sustainability, another important point is that energy savings generate improvement in consumption raising organizational profit. The methodologies used were a brief review of the literature and response surface methodology in a CCD experiment. The modeling of the specimen took place through the CAD Fusion 360 software, its development began with the creation of a rectangular 2D sketch, obeying the parameters of 80 mm in its length and 10 mm in width, an Ender 3 printer, yellow PLA, was used following the guidelines set out in ISO 178. Objective of the research is to optimize the manufacturing process using fused deposition modeling, reducing energy consumption (kwh). A complete factorial design was used , as factors: the printing speed (X1), the printing density (X2), layer height (X3) and the layer width (X4), as a response of the experiment were adopted for the manufacturing process, energy (Y). The residue normality tests were performed, with a p-value of 0.170 > 0.05, showing that the data are normal, the VIF below 10 and R-sq (adj) is above 87.16%, the equation has the validated model.

Additive manufacturing (AM) or 3D printing is a digital manufacturing process and offers virtually limitless opportunities to develop structures/objects by tailoring material composition, processing conditions, and geometry technically at every point in an object. In this review, we present three different early adopted, however, widely used, polymer-based 3D printing processes; fused deposition modelling (FDM), selective laser sintering (SLS), and stereolithography (SLA) to create polymeric parts. The main aim of this review is to offer a comparative overview by correlating polymer material-process-properties for three different 3D printing techniques. Moreover, the advanced material-process requirements towards 4D printing via these print methods taking an example of magneto-active polymers is covered. Overall, this review highlights different aspects of these printing methods and serves as a guide to select a suitable print material and 3D print technique for the targeted polymeric material-based applications and also discusses the implementation practices towards 4D printing of polymer-based systems with a current state-of-the-art approach.