scholarly journals Demonstration of a Polymer-Based Single Step Waveguide by 3D Printing Digital Light Processing Technology for Isopropanol Alcohol-Concentration Sensor

2021 ◽  
Author(s):  
Kankan Swargiary ◽  
Romuald Jolivot ◽  
Waleed Soliman Mohammed
Keyword(s):  
Refractive Index ◽  
3D Printing ◽  
Limit Of Detection ◽  
Optical Power ◽  
Alcohol Concentration ◽  
Single Step ◽  
Gap Size ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
The Core

AbstractA polymer based horizontal single step waveguide for the sensing of alcohol is developed and analyzed. The waveguide is fabricated by 3-dimensional (3D) printing digital light processing (DLP) technology using monocure 3D rapid ultraviolet (UV) clear resin with a refractive index of n = 1.50. The fabricated waveguide is a one-piece tower shaped ridge structure. It is designed to achieve the maximum light confinement at the core by reducing the effective refractive index around the cladding region. With the surface roughness generated from the 3D printing DLP technology, various waveguides with different gap sizes are printed. Comparison is done for the different gap waveguides to achieve the minimum feature gap size utilizing the light re-coupling principle and polymer swelling effect. This effect occurs due to the polymer-alcohol interaction that results in the diffusion of alcohol molecules inside the core of the waveguide, thus changing the waveguide from the leaky type (without alcohol) to the guided type (with alcohol). Using this principle, the analysis of alcohol concentration performing as a larger increase in the transmitted light intensity can be measured. In this work, the sensitivity of the system is also compared and analyzed for different waveguide gap sizes with different concentrations of isopropanol alcohol (IPA). A waveguide gap size of 300 µm gives the highest increase in the transmitted optical power of 65% when tested with 10 µL (500 ppm) concentration of IPA. Compared with all other gaps, it also displays faster response time (t = 5 seconds) for the optical power to change right after depositing IPA in the chamber. The measured limit of detection (LOD) achieved for 300 µm is 0.366 µL. In addition, the fabricated waveguide gap of 300 µm successfully demonstrates the sensing limit of IPA concentration below 400 ppm which is considered as an exposure limit by “National Institute for Occupational Safety and Health”. All the mechanical mount and the alignments are done by 3D printing fused deposition method (FDM).

Design, Development and Characterization of Linear, Soft Actuators via Additive Manufacturing

2018 ◽  
Author(s):  
Alfonso Costas ◽  
Daniel E. Davis ◽  
Yixian Niu ◽  
Sadegh Dabiri ◽  
Jose Garcia ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Single Step ◽  
Design Development ◽  
Initial Attempt ◽  
Fused Deposition ◽  
Piston Cylinder ◽  
Compact Size ◽  
Soft Actuators

Additive manufacturing has emerged as an alternative to traditional manufacturing technologies. In particular, industries like fluid power, aviation and robotics have the potential to benefit greatly from this technology, due to the design flexibility, weight reduction and compact size that can be achieved. In this work, the design process and advantages of using 3D printing to make soft linear actuators were studied and highlighted. This work explored the limitations of current additive manufacturing tolerances to fabricate a typical piston-cylinder assembly, and how enclosed bellow actuators could be used to overcome high leakage and friction issues experienced with a piston-cylinder type actuator. To do that, different 3D printing technologies were studied and evaluated (stereolithorgraphy and fused deposition modeling) in the pursuit of high-fidelity, cost-effective 3D printing. The initial attempt consisted of printing the soft actuators directly using flexible materials in a stereolithography-type 3D printer. However, these actuators showed low durability and poor performance. The lack of a reliable resin resulted in the replacement of this material by EcoFlex® 00-30 silicone and the use of a 3D printed mold to cast the actuators. These molds included a 3-D printed dissolvable core inside the cast actuator in order to finish the manufacturing process in one single step. An experimental setup to evaluate the capabilities of these actuators was developed. Results are shown to assess the steady-state and the dynamic characteristics of these actuators. These tests resulted into the stroke-pressure and stroke-time responses for a specific load given different proportional valve inputs.

scholarly journals 3D Printing of Thermo-Sensitive Drugs

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1524
Author(s):  
Sadikalmahdi Abdella ◽  
Souha H. Youssef ◽  
Franklin Afinjuomo ◽  
Yunmei Song ◽  
Paris Fouladian ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Future Directions ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
Printing Technique ◽  
3D Printed ◽  
Semi Solid ◽  
Selection Of

Three-dimensional (3D) printing is among the rapidly evolving technologies with applications in many sectors. The pharmaceutical industry is no exception, and the approval of the first 3D-printed tablet (Spiratam®) marked a revolution in the field. Several studies reported the fabrication of different dosage forms using a range of 3D printing techniques. Thermosensitive drugs compose a considerable segment of available medications in the market requiring strict temperature control during processing to ensure their efficacy and safety. Heating involved in some of the 3D printing technologies raises concerns regarding the feasibility of the techniques for printing thermolabile drugs. Studies reported that semi-solid extrusion (SSE) is the commonly used printing technique to fabricate thermosensitive drugs. Digital light processing (DLP), binder jetting (BJ), and stereolithography (SLA) can also be used for the fabrication of thermosensitive drugs as they do not involve heating elements. Nonetheless, degradation of some drugs by light source used in the techniques was reported. Interestingly, fused deposition modelling (FDM) coupled with filling techniques offered protection against thermal degradation. Concepts such as selection of low melting point polymers, adjustment of printing parameters, and coupling of more than one printing technique were exploited in printing thermosensitive drugs. This systematic review presents challenges, 3DP procedures, and future directions of 3D printing of thermo-sensitive formulations.

scholarly journals 3D printers in dentistry: a review of additive manufacturing techniques and materials

2021 ◽  
Author(s):  
Leonardo Portilha Gomes da Costa ◽  
Stephanie Isabel Díaz Zamalloa ◽  
Fernando Amorim Mendonça Alves ◽  
Renan Spigolon ◽  
Leandro Yukio Mano ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Dental Materials ◽  
Clinical Results ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
3D Printers ◽  
Manufacturing Techniques ◽  
Printed Materials

3D printers manufacture objects used in various dental specialties. Objective: This literature review aims to explore different techniques of current 3D printers and their applications in printed materials for dental purposes. Methods: The online PubMed databases were searched aiming to find applications of different 3D printers in the dental area. The keywords searched were 3D printer, 3D printing, additive manufacturing, rapid prototyping, 3D prototyping, dental materials and dentistry. Results: From the search results, we describe Stereolithography (SLA), Digital Light Processing (DLP), Material Jetting (MJ), Fused Deposition Modeling (FDM), Binder Jetting (BJ) and Dust-based printing techniques. Conclusion: 3D printing enables different additive manufacturing techniques to be used in dentistry, providing better workflows and more satisfying clinical results.

scholarly journals The Chronotopic™ System for Pulsatile and Colonic Delivery of Active Molecules in the Era of Precision Medicine: Feasibility by 3D Printing via Fused Deposition Modeling (FDM)

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 759
Author(s):  
Alice Melocchi ◽  
Marco Uboldi ◽  
Francesco Briatico-Vangosa ◽  
Saliha Moutaharrik ◽  
Matteo Cerea ◽  
...  
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Single Step ◽  
Lag Phase ◽  
Colonic Delivery ◽  
Intestinal Transit Time ◽  
Small Intestinal Transit ◽  
Colon Targeting ◽  
Fused Deposition ◽  
Deposition Modeling

The pulsatile-release Chronotopic™ system was conceived of as a drug-containing core surrounded by a coat made of swellable/soluble hydrophilic polymers, the latter being able to provide a programmable lag phase prior to drug liberation. This system was also proposed in a colon-targeting configuration, entailing a gastroresistant film to prevent early interaction of the inner coat with gastric fluids and enabling the attainment of a lag phase matching the small intestinal transit time. Over the years, various multiple-step manufacturing processes have been tested for the fabrication of the Chronotopic™ system in both its configurations. This work focused on the evaluation of 3D printing by fused deposition modeling in view of its potential towards product personalization, on demand one-step manufacturing and efficient scale down of batches. The feasibility of each part of the Chronotopic™ system was independently investigated starting from in-house made filaments, characterizing the resulting specimens for physico-technological and performance characteristics. The printing parameters identified as suitable during the set-up phase were then used to fabricate prototypes either in a single step for the pulsatile configuration or following two different fabrication approaches for the colon-targeting one.

scholarly journals Enhanced Supersaturation via Fusion-Assisted Amorphization during FDM 3D Printing of Crystalline Poorly Soluble Drug Loaded Filaments

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1857
Author(s):  
Guluzar Gorkem Buyukgoz ◽  
Christopher Gordon Kossor ◽  
Rajesh N. Davé
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Dissolution Kinetics ◽  
Single Step ◽  
Water Soluble ◽  
Processing Temperature ◽  
Fused Deposition ◽  
Surface Areas ◽  
Lower Temperature ◽  
The Impact

Filaments loaded with griseofulvin (GF), a model poorly water-soluble drug, were prepared and used for 3D printing via fused deposition modeling (FDM). GF was selected due to its high melting temperature, enabling lower temperature hot-melt extrusion (HME) keeping GF largely crystalline in the filaments, which could help mitigate the disadvantages of high HME processing temperatures such as filament quality, important for printability and the adverse effects of GF recrystallization on tablet properties. Novel aspects include single-step fusion-assisted ASDs generation during FDM 3D printing and examining the impact of tablet surface areas (SA) through printing multi-mini and square-pattern perforated tablets to further enhance drug supersaturation during dissolution. Kollicoat protect and hydroxypropyl cellulose were selected due to their low miscibility with GF, necessary to produce crystalline filaments. The drug solid-state was assessed via XRPD, DSC and FT-IR. At 165 °C HME processing temperature, the filaments containing ~80% crystalline GF were printable. Fusion-assisted 3D printing led to GF supersaturation of ~153% for cylindrical tablets and ~293% with the square-pattern perforated tablets, indicating strong monotonous impact of tablet SA. Dissolution kinetics of drug release profiles indicated Fickian transport for tablets with higher SA, demonstrating greater SA-induced drug supersaturation for well-designed 3D printed tablets.

scholarly journals Analysis of FDM and DLP 3D-Printing Technologies to Prototype Electromagnetic Devices for RFID Applications

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 897
Author(s):  
Riccardo Colella ◽  
Francesco Paolo Chietera ◽  
Luca Catarinucci
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Careful Analysis ◽  
Research Activity ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
Electromagnetic Devices ◽  
Radiofrequency Identification ◽  
Rf Devices ◽  
Deposition Modeling

In this work, the application in Radiofrequency Identification (RFID) of different additive manufacturing (AM) 3D-printing technologies is discussed. In particular, the well-known Fused Deposition Modeling (FDM) technology is compared with the promising Digital Light Processing (DLP), which is based on the photopolymerization of liquid resins. Based on the research activity of the authors on this topic, a brief introduction to the fundamentals of 3D-printing in electromagnetics as well as to the different applications of both FDM and DLP in realizing Radio Frequency (RF) devices, is firstly given. Then, a comparison of the two technologies is deeply faced. Finally, after evaluated the rugosity of substrates produced with both techniques to verify the potential impact on the design of electromagnetic structures, the two techniques are both exploited for the realization of the dielectric parts of a tunable RFID tag with unconventional shape. It consists of two elements interlinked one each other. The movement between them enables tuning of the resonance frequency as well as the impedance of the antenna. Despite the differences in terms of losses, rugosity, resolution, and dielectric constant, both techniques guaranteed satisfactory values of tag sensitivity, maximum reading range, and tunability. Nevertheless, the careful analysis of the results proposed at the end of the paper suggests how the selection of one technique over the other must be taken considering the specific application constraints.

scholarly journals Economic and technogical considerations on the 3d printing components in university laboratories made from students

2019 ◽  
Vol XXII (1) ◽  
pp. 261-268
Author(s):  
Vasilescu M. D.
Keyword(s):  
3D Printing ◽  
Physical And Mechanical Properties ◽  
Point Of View ◽  
Fused Deposition Modelling ◽  
Technological Parameters ◽  
Digital Light Processing ◽  
Practical Applications ◽  
Technical Parameters ◽  
Fused Deposition ◽  
Component Design

The scope of this research is to analyse the economic aspects of the 3D printing parts for making parts and functional sub-assemblies for different machinery. The author intends in this work to make a clarification on the economic approaches of processing FDM (Fused Deposition Modelling) and DLP (Digital Light Processing) materials which can be used for generating mechanically required items. The paper it is structured in 5 chapters. In the first chapter, there is an ordering of the materials based on the literature, but also from its own experience in generating parts by 3D printing. Synthesis is made both in terms of physical and mechanical properties, but also from the point of view of economic as well. It should be shown that the comparison will also be made from the point of view of 3D printing generation since two different printing processes are used both as the principle of generation and the way of obtaining the 3D parts. For generating, two printers will be used, which both constructively and functionally will be analysed, both as functionality and as component design possibilities. The second chapter affected to the ordering of technological parameters of 3D generation by printing the parts with defining the main technical parameters of generation of the parts. This step is important both to ensure the assembly conditions of the components, but also to the fact that the materials used to make the parts produce different comportment after the three directions in terms of contractions and the variation of the dimensions. The third chapter analyses the main ways of generating the parts with the presentation of some of the domain-specific elements generated by 3D printing with FDM and DLP. In the fourth chapter is presented the economic calculation program made with practical applications related to the parts generated in the previous chapter. The last chapter is allocated to the conclusions and comparisons from the technologicaleconomical point of view compared to other specific technologies for generating the analysed parts.

scholarly journals Reproducibility of linear measurements performed in dental models from 3D printing

2021 ◽  
Vol 10 (11) ◽  
pp. e344101113370
Author(s):  
Fernanda Latorre Melgaço Maia ◽  
Ademir Franco ◽  
Daphne Azambuja Hatschbach de Aquino ◽  
Luciana Butini Oliveira ◽  
José Luiz Cintra Junqueira ◽  
...  
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Intraclass Correlation ◽  
Linear Measurements ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
Intraoral Scanning ◽  
Dental Models ◽  
3D Printed

This study aimed to assess the reproducibility of linear measurements performed in dental models produced via intraoral scanning and three-dimensional (3D) printing using digital light processing (DLP) and fused deposition modeling (FDM). A sample of 22 participants was selected for this study. Intraoral scanning was performed in each participant with TRIOS™ (3Shape A/S™, Copenhagen, Denmark) device. The digital models were 3D printed using DLP and FDM techniques. Using a caliper, intraoral linear measurements were performed in situ (on the surface of participant’s teeth) and on the 3D printed models. The measurements taken intraoral and on the models were compared using the Intraclass Correlation Coefficient (ICC). The correlation between measurements taken in situ and on DLP models was poor (<0.4), while between in situ and FDM it ranged from poor to satisfactory (<0.75). Generalized linear model showed that the differences did not reach statistically significant levels (p>0.05). According to Bland-Altman approach, the size of measurements did not bias the outcomes. The intraoral scanning and 3D printing techniques used in this study enabled the reproducibility of linear measurements, however, discrete distortions that might be clinically significant occurred.

scholarly journals Fabrication PEGDA/ANFs Biomaterial as 3D Tissue Engineering Scaffold by DLP 3D Printing Tecshnology

2019 ◽  
Vol 8 (6) ◽  
pp. 751-758 ◽  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Selective Laser Sintering ◽  
3D Structure ◽  
Tissue Engineering Scaffold ◽  
3D Scaffold ◽  
Digital Light Processing ◽  
Printing Process ◽  
Glycol Diacrylate ◽  
Fused Deposition

Although traditional fabrication methods (electrospinning, solvent casting, freeze drying, etc...) can be used to produce scaffold, unfortunately, each of them has many limitations such as difficulty to control distinct 3D structure and porosity. These limitations can be easily overcome by unconventional techniques such as Fused Deposition Method (FDM), Selective Laser Sintering (SLS) and Stereolithography (SLA) to produce tissue engineering scaffold. Among the three, SLA offers the lowest cost, fastest printing speed and highest resolution. Digital light processing (DLP) 3D printing process is one of the SLA techniques which has been used a lot to fabricate tissue engineering scaffold based on Poly (ethylene glycol) diacrylate (PEGDA) material. However, there is no report published on the fabrication of tissue engineering scaffold based PEGDA filled with Aramid Nanofiber (ANFs). Hence, the feasible parameter setting for fabricating this material using DLP technique is currently unknown. The aim of this work is to establish the best feasible condition to fabricate PEGDA/ANFs 3D scaffold. ANFs was synthesized first from macro size Kevlar fiber prior to crosslinking with Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) photoinitiator. The mixing ratio of PEGDA resin to ANFs was fixed to 9:1. The concentration of TPO was varied at 0.5, 1.0 and 1.7% wt. while the resin concentration was fixed at 30% during the mixing to produce three set of biomaterials. Calibration printing was conducted prior to actual printing with the purpose of eliminating unprintable TPO concentration. The final scaffold was printed using DLP machine (FEMTO…) at two different curing times i.e 70 and 80s to obtain a good shape and printable 3D structure. The synthesized ANFs showed that a single diameter in nano size at a range of 50 nm ~ 80 nm was able to produce. During calibration printing, it was found that 1.7%wt of TPO failed to produce a 3D profile shape. The final printing results of 0.5%wt and 1%wt of TPO were compared after being cured at 70s and 80s. It was observed that the printed 3D scaffold of 1%wt TPO at 70s curing time produces the most discernable shape of tensile specimen (ISO 37:2011) than the other three conditions. The findings from this study can be potentially used a guideline for developing a 3D structure of tissue engineering scaffold by using DLP 3D printing process.

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