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Article
Publication date: 26 April 2011

Amit S. Jariwala, Fei Ding, Aparna Boddapati, Victor Breedveld, Martha A. Grover, Clifford L. Henderson and David W. Rosen

The purpose of this paper is to present a model that can be used to simulate the photopolymerization process in micro‐stereolithography (SL) in order to predict the shape of the…

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Abstract

Purpose

The purpose of this paper is to present a model that can be used to simulate the photopolymerization process in micro‐stereolithography (SL) in order to predict the shape of the cured parts. SL is an additive manufacturing process in which liquid photopolymer resin is cross‐linked and converted to solid with a UV laser light source. Traditional models of SL processes do not consider the complex chemical reactions and species transport occurring during photopolymerization and, hence, are incapable of accurately predicting resin curing behavior. The model presented in this paper attempts to bridge this knowledge gap.

Design/methodology/approach

The chemical reactions involved in the photopolymerization of acrylate‐based monomers were modeled as ordinary differential equations (ODE). This model incorporated the effect of oxygen inhibition and diffusion on the polymerization reaction. The model was simulated in COMSOL and verified with experiments conducted on a mask‐based micro‐SL system. Parametric studies were conducted to investigate the possibilities to improve the accuracy of the model for predicting the edge curvature.

Findings

The proposed model predicts well the effect of oxygen inhibition and diffusion on photopolymerization, and the model accurately predicts the cured part height when compared to experiments conducted on a mask‐based SL system. The simulated results also show the characteristic edge curvature as seen in experiments.

Research limitations/implications

A triacrylate monomer was used in the experiments conducted, so results may be limited to acrylate monomers. Shrinkage was not considered when comparing cured part shapes to those predicted using COMSOL.

Originality/value

This paper presents a unique and a pioneering approach towards modeling of the photopolymerization reaction in micro‐SL process. This research furthers the development of patent pending film micro‐SL process which can be used for fabrication of custom micro‐optical components.

Details

Rapid Prototyping Journal, vol. 17 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 24 September 2024

Danilo Calderone, Giuseppe Cesarelli, Carlo Ricciardi, Francesco Amato and Fabrizio Clemente

This paper aims to present a systematic review of the latest scientific literature, in the context of pediatric orthopedics, on the development by additive manufacturing of…

Abstract

Purpose

This paper aims to present a systematic review of the latest scientific literature, in the context of pediatric orthopedics, on the development by additive manufacturing of anatomical models, orthoses, surgical guides and prostheses and their clinical applications.

Design/methodology/approach

Following the current guidelines for systematic reviews, three databases (Elsevier Scopus®, Clarivate Web of ScienceTM and USA National Library of Medicine PubMed®) were screened using a representative query to find pertinent documents within the timeframe 2016–2023. Among the information, collected across the reviewed documents, the work focused on the 3D printing workflow involving acquisition, elaboration and fabrication stages.

Findings

Following the inclusion and exclusion criteria, the authors found 20 studies that fitted the defined criteria. The reviewed studies mostly highlighted the positive impact of additive manufacturing in pediatric orthopedic surgery, particularly in orthotic applications where lightweight, ventilated and cost-effective 3D-printed devices demonstrate efficacy comparable to traditional methods, but also underlined the limitations such as printing errors and high printing times. Among the reviewed studies, material extrusion was the most chosen 3D printing technology to manufacture the typical device, particularly with acrylonitrile butadiene styrene.

Originality/value

To the best of the authors’ knowledge, this is the first systematic review which annotates, from a more engineering point of view, the latest literature on the admittance of the clinical application of additive manufacturing (and its effects) within typical pediatric orthopedic treatments workflows.

Details

Rapid Prototyping Journal, vol. 30 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 12 September 2024

Sérgio B Gonçalves, Pedro Dantas, Francisco Guedes de Melo, João Gouveia, José Guimarães Consciência, Jorge Martins and Miguel Tavares da Silva

Arthroscopic osteochondroplasty is a minimally invasive procedure that has been used to treat femoroacetabular impingement syndrome, leading to significant improvements in…

Abstract

Purpose

Arthroscopic osteochondroplasty is a minimally invasive procedure that has been used to treat femoroacetabular impingement syndrome, leading to significant improvements in patients’ clinical outcomes and quality of life. However, some studies suggest that inadequate bone resection can substantially alter hip biomechanics. These modifications may generate different contact profiles and higher contact forces, increasing the risk of developing premature joint degeneration. To improve control over bone resection and biomechanical outcomes during arthroscopic osteochondroplasty surgery, this study aims to present a novel system for measuring femoroacetabular contact forces.

Design/methodology/approach

Following a structured design process for the development of medical devices, the steps required for its production using additive manufacturing with material extrusion and easily accessible sensors are described. The system comprises two main devices, one for measuring femoroacetabular contact forces and the other for quantifying the force applied by the assistant surgeon during lower limb manipulation. The hip device was designed for use within an arthroscopic environment, eliminating the need for additional portals.

Findings

To evaluate its performance, the system was first tested in a laboratory setup and later under in-service conditions. The 3D printing parameters were tuned to ensure the watertighness of the device and sustain the intraoperative fluid pressures. The final prototype allowed for the controlled measurement of the hip contact forces in real-time.

Originality/value

Using additive manufacturing and readily available sensors, the present work presents the first device to quantify joint contact forces during arthroscopic surgeries, serving as an additional tool to support the surgeon’s decision-making process regarding bone resection.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 14 January 2022

Jose Manuel Sierra, Maria del Rocio Fernandez, Jose Ignacio Ignacio Rodriguez Garcia, Jose Luis Cortizo and Marta María Villazon

This paper describes the evolution of the design of a mechanical distractor fabricated using additive manufacturing (AM) technology for use in surgical procedures, such as…

Abstract

Purpose

This paper describes the evolution of the design of a mechanical distractor fabricated using additive manufacturing (AM) technology for use in surgical procedures, such as transanal endoscopic microsurgery (TEM). The functionality of the final device was analysed and the suitability of different materials was determined.

Design/methodology/approach

Solid modelling and finite element modelling software were used in the design and validation process to allow the fabrication of the device by AM. Several prototypes were manufactured and tested in this study.

Findings

A new design was developed to greatly simplify the existing devices used in TEM surgery. The new design is easy to use, more economical and does not require pneumorectum. Different AM materials were investigated with regard to their mechanical properties, orientation of parts in the three-dimensional (3D) printer and cytotoxicity to select the optimal material for the design.

Social implications

The device designed by AM can be printed anywhere in the world, provided that a 3D printer is available; the 3D printer does not have to be a high-performance printer. This makes surgery more accessible, particularly in low-income regions. Moreover, patient recovery is improved and pneumorectum is not required.

Originality/value

A suitable mechanical distractor was designed for TEM, and different materials were validated for fabrication by AM.

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