Anton Du Plessis

Anton Du Plessis
Object Research Systems

PhD
X-ray tomography, additive manufacturing & biomimicry

About

298
Publications
101,985
Reads
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5,216
Citations
Citations since 2017
213 Research Items
4999 Citations
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Introduction
I am a researcher and applications scientist. As applications scientist at Object Research Systems, I demonstrate and develop workflows for image processing and analysis using Dragonfly software, which is available for a free trial and free for academic use - fully functional and forever - http://orss.ca/getDF My research is mainly in advanced engineering materials, additive manufacturing and characterization of these materials using X-ray CT imaging.
Additional affiliations
July 2021 - present
Central University of Technology
Position
  • Professor
July 2021 - present
Elsevier B.V.
Position
  • Editor
December 2019 - July 2021
Elsevier B.V.
Position
  • Editor

Publications

Publications (298)
Article
Full-text available
X-ray microcomputed tomography (microCT) has become an established method of testing and analyzing additively manufactured parts in recent years, being especially useful and accurate for dimensional measurement and porosity analysis. While this nondestructive analysis method is gaining traction among additive manufacturing (AM) researchers and engi...
Article
Albert Einstein once said “look deep into nature, and then you will understand everything better”. Looking deep into nature has in the last few years become much more achievable through the use of high-resolution X-ray micro-computed tomography (microCT). The non-destructive nature of microCT, combined with three-dimensional visualization and analy...
Article
Full-text available
Metal additive manufacturing involves manufacturing techniques that add material to produce metallic components, typically layer by layer. The substantial growth in this technology is partly driven by its opportunity for commercial and performance benefits in the aerospace industry. The fundamental opportunities for metal additive manufacturing in...
Article
Full-text available
Additive manufacturing of industrially-relevant high-performance parts and products is today a reality, especially for metal additive manufacturing technologies. The design complexity that is now possible makes it particularly useful to improve product performance in a variety of applications. Metal additive manufacturing is especially well matured...
Preprint
Full-text available
This review article summarizes the current state-of-the-art for biomimicry in additive manufacturing. Biomimicry is the practice of learning from and emulating nature - which can be increasingly realized in engineering applications due to progress in additive manufacturing (AM). AM has grown tremendously in recent years, with improvements in techno...
Article
Full-text available
Image-Based Simulation (IBSim) is the process by which a digital representation of a real geometry is generated from image data for the purpose of performing a simulation with greater accuracy than with idealised Computer Aided Design (CAD) based simulations. Whilst IBSim originates in the biomedical field, the wider adoption of imaging for non-des...
Chapter
This chapter provides the first descriptions of the intact paranasal sinuses of the Hofmeyr cranium, which include both frontal sinusesFrontal- sinus and the right maxillary sinusMaxillary sinus, and compares these structures across Recent and fossil Homo sapiens. In comparison to Recent human samples, the Hofmeyr cranium presents with absolutely a...
Article
Full-text available
Metal additive manufacturing of titanium and its alloys can produce complicated geometries cost-effectively while maintaining biocompatibility. It is known that the material property differences between bone and Ti6Al4V cause stress shielding, leading to bone failure around the implant. Using lattice structures is effective at reducing elastic modu...
Article
The fatigue behaviour of as-built parts produced by means of Laser-Powder Bed Fusion process (L-PBF) is primarily influenced by the presence of stress raisers on the surface, whose morphology strongly depends on the relative orientation between the surface and the build direction. This study aims to shed light into the factors representing the surf...
Article
Full-text available
Our current understanding of the spectrum of TB and COVID-19 lesions in the human lung is limited by a reliance on low-resolution imaging platforms that cannot provide accurate 3D representations of lesion types within the context of the whole lung. To characterize TB and COVID-19 lesions in 3D, we applied micro/nanocomputed tomography to surgicall...
Article
Full-text available
The frontal sinuses are cavities inside the frontal bone located at the junction between the face and the cranial vault and close to the brain. Despite a long history of study, understanding of their origin and variation through evolution is limited. This work compares most hominin species’ holotypes and other key individuals with extant hominids....
Article
‘Scaloposaurs’ represent a wastebasket taxon of small therocephalian therapsids once believed to be close to the evolutionary ancestry of mammals. The group is now thought to be made up of mostly paedomorphic or juvenile therocephalians belonging to various families. Here, a new large therocephalian is described from the Early Triassic Lystrosaurus...
Preprint
In recent years, laser powder bed fusion of aluminum alloys has attracted extensive attention due to their capacious application in the biomedical, aerospace, and other industrial sectors. This is due to the combined capabilities of the laser powder bed fusion process and aluminum alloys bringing about complex shapes with high performance associate...
Preprint
The combined benefit of both additive and subtractive manufacturing within the same gantry system enables hybrid directed energy deposition to create complex geometries with smooth surface finish and superior dimensional accuracy. Moreover, with layer-by-layer access to the structure during both the addition and subtraction of material, the inserti...
Article
The functional significance of osteoderms—bony elements embedded in the dermis—remains a topic of much debate. Although many hypotheses have been put forward in the past, the idea that osteoderms can serve as calcium reservoirs has received little experimental attention thus far. In this study, we use micro-computed tomography to investigate inter-...
Article
Full-text available
Nature provides an infinite source of inspiration for innovative designs that may be required to tackle the social, economic, and environmental challenges the world faces. Despite the surging popularity and prevalence, the discipline of bioinspiration is limited in unleashing its full potential by the inadequate understanding of biological and evol...
Article
Additive manufacturing (AM) components can benefit medical applications by improving their functionality and/or providing well fit custom designs. Metal and polymer AM potential can be perfectly expanded to composite materials, such as metal-ceramics, polymer-ceramics, polymer-metal, etc. These components have unique properties that can be benefici...
Article
Here we provide the first phylogenetic analysis that include Afrogecko ansorgii and a detailed morphological comparison with other species of leaf-toed geckos. For this purpose, we used two mitochondrial (16S, ND2) and four nuclear (RAG1, RAG2, CMOS, PDC) genes to produce a robust phylogenetic reconstruction. This allowed us to show that A. ansorgi...
Article
Titanium is a versatile biocompatible metal that is desirable in additively manufactured medical implant devices. However, additively manufactured parts have particular microstructures, porosity, residual stress, and surface conditions which can have a strong impact on fatigue performance. Implants have an added complexity from the saline operating...
Article
Full-text available
Additively manufactured (AM) lattice structures are applied in high-value applications such as lightweight aerospace design and biomedical implants. However, uncertainties of the geometry of as-manufactured AM lattice structures results in uncertainties in the associated mechanical response. This research proposes a non-destructive digital-twin cer...
Article
Elements fabricated by extrusion-based 3D concrete printing (3DCP) display anisotropic mechanical properties when subject to loading conditions orientated in principle cartesian axis directions. Various studies show that the mechanical characteristics of 3DCP components are lower than their mould-cast counterparts, reportedly due to the existence o...
Article
The hardened-state mechanical characteristics of 3D printable concrete (3DPC) mixtures exhibit a strong dependence on the employed extrusion-based process, material, and design parameters and are predominantly anisotropic by nature. It has been shown that at the heart of the observed mechanical anisotropy lies the microstructural morphology of the...
Article
Laser powder bed fusion (LPBF) is receiving widespread attention for its capability to build components with complex geometries. Post-processing can address the adverse effects of various imperfections exhibited in LPBF parts in their as-built state, including inhomogeneous microstructure, tensile residual stresses and poor surface quality. In a re...
Chapter
Beautiful and functional—the perfect combination of nature’s beauty and engineering functionality–best describes the synergy between biomimicry and additive manufacturing. Nature has proven to be a valuable source of inspiration for design solutions with many success stories, yet critical gaps between biological and engineering domains prevent biom...
Preprint
Titanium is a versatile biocompatible metal that is desirable in additively manufactured medical implant devices. However, additively manufactured parts have particular microstructures, porosity, residual stress and surface conditions which can have a strong impact on fatigue performance. Implants have an added complexity from the saline operating...
Article
Additive manufacturing (AM) of metal components is increasingly used in high performance applications, especially in the aerospace industry. Laser powder bed fusion (L-PBF) of metals is the most widely used and mature process for this purpose, but it comes with some challenges. One of these challenges involves manufacturing quality and associated m...
Article
Full-text available
Additive manufacturing (AM) refers to a collection of manufacturing methods involving the incremental addition of material to build a part directly in its final or near-final geometry, usually in a layer-by-layer process. Metal AM in particular has seen great industrial adoption and maturation. This technology enables increased freedom of design in...
Article
Additively manufactured lattice structures of titanium alloys, especially Ti6Al4V, are widely studied for their use in bone replacement implants. The porous nature of these lattice structures reduces the effective elastic modulus and hence can be matched to that of bone, in order to reduce stress shielding effects and allow long-term bone in-growth...
Article
X-ray computed tomography (CT) can reveal the internal details of objects in three dimensions non-destructively. In this Primer, we outline the basic principles of CT and describe the ways in which a CT scan can be acquired using X-ray tubes and synchrotron sources, including the different possible contrast modes that can be exploited. We explain t...
Article
Full-text available
X-ray computed tomography is a common tool for non-destructive testing and analysis. One major application of this imaging technique is 3D porosity identification and quantification, which involves image segmentation of the analysed dataset. This segmentation step, which is most commonly performed using a global thresholding algorithm, has a major...
Article
Full-text available
Demand for the construction of new structures is increasing all over the world. Since the construction sector dominates the global carbon footprint, new construction methods are needed with reduced embodied carbon and high resource efficiency to realize a sustainable future. In this direction, Metal Additive Manufacturing, also known as 3D printing...
Article
Full-text available
Polyetheretherketone (PEEK) has been the focus of substantial additive manufacturing research for two principal reasons: (a) the mechanical performance approaches that of aluminum at relatively high temperatures for thermoplastics and (b) the potential for qualification in both the aerospace and biomedical industries. Although PEEK provides outstan...
Article
Full-text available
Recently, there has been an increasing interest on the sustainability advantage of 3D concrete printing (3DCP), where the original cement-based mixtures used for printing could be replaced or incorporated with environmental-friendly materials. The development in digital modeling and design tools also creates a new realm of form-finding architecture...
Article
Full-text available
The fatigue performance of additively manufactured auxetic meta-biomaterials made from commercially pure titanium has been studied only recently. While certain assumptions have been made regarding the mechanisms underlying their fatigue failure, the exact mechanisms are not researched yet. Here, we studied the mechanisms of crack formation and prop...
Article
Laser powder bed fusion (LPBF) as an additive manufacturing technology offers high potential to fabricate parts with complex geometries layer-by-layer. However, these parts have inhomogeneous microstructure and very poor surface quality in their as-built condition. The presence of high surface irregularities especially in the downskin surfaces is a...
Article
Additive manufacturing is now leveraged to digitally fabricate complex and customized sand molds for castings. Mathematical equations can be employed in design to gracefully vary strut sizings volumetrically within lattices and the corresponding sand molds can be realized with binder jetting additive manufacturing. Consequently, geometrically tailo...
Conference Paper
Full-text available
In laser powder bed fusion (L-PBF) of polymers, a proven material for biomedical applications is Polyamide12(PA 12) that is used for production of functional prototypes and end-use parts. The aim of this study is to investigate properties of insitu copper -modified polyamide (Sintratec PA12/B) at 10 wt.% Cu by L-PBF. Polymer-metal composites test s...
Article
Full-text available
Metal powder bed fusion in additive manufacturing is gaining interest as a manufacturing technique for complex metal parts in the aerospace, rail, and automotive industries. This has led to an emergence of 3D printers in the market to accelerate the diffusion of this technology as an industrial manufacturing technique. The Aeroswift is an additive...
Article
Full-text available
Additive manufacturing of ceramics is transforming electromagnetics by providing density-varying lattices and stochastic foams within arbitrary envelopes. Periodic structures can now be fabricated with zirconia which offers the highest permittivity of any 3D printable material possible to be printed with nearly-full-density. By arranging a lattice...
Article
Full-text available
Quality concerns in laser powder bed fusion (L-PBF) include porosity, residual stresses and deformations during processing. Single tracks are the fundamental building blocks in L-PBF and their shape and geometry influence subsequent porosity in 3D L-PBF parts. The morphology of single tracks depends primarily on process parameters. The purpose of t...
Conference Paper
Full-text available
The composition and evolution of kimberlitic magma has been proposed to form either as primary carbonatitic melts that during their ascent are contaminated by lithospheric silicate components, or by segregation of primary carbonated silicate melts in the kimberlite source. The highly dynamic and rapid magma transport and alteration of kimberlites d...
Article
Full-text available
Additive manufacturing of ceramics stands to transform applications requiring wear resistance in severe environments (including high temperatures and pressures, harsh chemicals, and biomedical implants, among many other uses). However, applications in electromagnetics are gaining increased attention as newly-available materials like zirconia provid...
Chapter
One of the major hurdles of laser powder bed fusion (L-PBF) is the inconsistent fatigue performance, depending on many possible defect types, microstructural differences, surface roughness effects, residual stresses and more, as described in other chapters in this book. Many improvements have been made in material properties by L-PBF process optimi...
Article
Rationale: Our current understanding of tuberculosis pathophysiology is limited by a reliance on animal models, the paucity of human tuberculosis lung tissue, and traditional histopathological analysis, a destructive two-dimensional approach that provides limited spatial insight. Determining the three-dimensional (3D) structure of the necrotic gran...
Article
Full-text available
Quantifying insect respiratory structures and their variation has remained challenging due to their microscopic size. Here we measure insect tracheal volume using X-ray micro-tomography (μCT) scanning (at 15 μm resolution) on living, sedated larvae of the cerambycid beetle Cacosceles newmannii across a range of body sizes. In this paper we provide...
Article
Laser powder bed fusion (LPBF) is a promising technology that requires further work to improve productivity to be adopted more widely. One possible approach is to increase the laser power and scan speed. A customized high-speed and high-power LPBF system has been developed for this purpose. The current study investigated the surface roughness and n...
Preprint
Full-text available
Quantifying insect respiratory structures and their variation has remained challenging due to their microscopic size. Here we measure insect tracheal volume using X-ray micro-tomography (µCT) scanning (at 15 µm resolution) on living, sedated larvae of the cerambycid beetle Cacosceles newmannii across a range of body sizes. In this paper we provide...
Article
Full-text available
SYNOPSIS Additive manufacturing can be used to produce complex and custom geometries, consolidating different parts into one, which in turn reduces the required number of assemblies and allows distributed manufacturing with short lead times. Defects, such as porosity and surface roughness, associated with parts manufactured by laser powder bed fusi...
Book
Full-text available
Laser powder bed fusion of metals is a technology that makes use of a laser beam to selectively melt metal powder layer-by-layer in order to fabricate complex geometries in high performance materials. The technology is currently transforming aerospace and biomedical manufacturing and its adoption is widening into other industries as well, including...
Chapter
Porosity in Additive Manufacturing (AM) is a widespread concern. Pores are often found to negatively influence the mechanical properties, especially fatigue performance, of additively manufactured parts. Laser Powder Bed Fusion (L-PBF) is arguably the AM technology that is best suited to produce complex end-use components for critical applications....
Article
Full-text available
Meta-biomaterials offer a promising route towards the development of life-lasting implants. The concept aims to achieve solutions that are ordinarily impossible, by offering a unique combination of mechanical, mass transport, and biological properties through the optimization of their small-scale geometrical and topological designs. In this study,...
Article
Full-text available
Lattice structures can be highly complex imitating natural cellular materials. By the wide adoption of additive manufacturing technologies, lattice structures are a popular design element with many advantages for lightweight and highly functional parts. A detailed examination and an intense inspection of this type of new design element and this new...
Article
Full-text available
The monetary value of gemstones is based on five variables: rarity, cut, weight, color and clarity. The latter refers to internal impurities and defects. Fashion may also dictate demand and price. To enhance some of these features and value, gemstones are treated. Disclosure or nondisclosure thereof has been controversial and affected consumer conf...
Article
In this study X-ray computed tomography (X-ray CT) was used to determine microstructural properties of ‘Fuji’ apple (Malus domestica Borkh.) tissue affected by internal browning (IB) and unaffected tissue after short-term exposure (3 days) to a storage atmosphere with 0.1 % O2 and 50 % CO2. The incidence of IB disorders were concentrated in the cor...
Article
Full-text available
How respiratory structures vary with, or are constrained by, an animal’s environment is of central importance to diverse evolutionary and comparative physiology hypotheses. To date, quantifying insect respiratory structures and their variation has remained challenging due to their microscopic size, hence only a handful of species have been examined...
Article
Full-text available
In laser powder bed fusion (L-PBF), the mechanical performance and especially fatigue properties of fabricated parts are significantly improved by hot isostatic pressing (HIP) as the density increases (pores are closed) and the microstructure improves. HIP ensures consistent and defect-free material, and consequently, this high temperature and high...
Article
Citrus tristeza virus (CTV) is the most important viral pathogen of citrus. CTV-induced stem pitting negatively impacts grapefruit and sweet orange production. The mechanisms of stem pitting development in CTV-infected citrus remain unclear. This study evaluated the utility of high-resolution computed tomography (CT) scanning as a tool to study ste...
Article
Concrete structures additively manufactured by extrusion-based 3D concrete printing are reportedly orthotropic in mechanical behavior and exhibit relative weakness in interfacial regions. Microstructure, including porosity content, 3D porosity distribution and pore morphology presents a physical basis for these phenomena. Here, a first and comprehe...
Chapter
This short chapter provides a practical case study which can be followed step by step by reading the chapter or by designing and manufacturing the same part. It provides a practical test case to demonstrate some of the concepts presented in the book, aiming at students and new users. This is meant primarily as a simple low-cost exercise for buildin...
Chapter
Laser Powder Bed Fusion (L-PBF) technology is increasingly important for the fabrication of innovative engineering systems, including functionally integrated systems, bespoke medical implants, and high-value optimized structures. Increasingly, these engineered systems are well understood from a technical perspective; however, a remaining challenge...
Chapter
This chapter aims to provide a broad overview introducing all relevant concepts and terminology in Additive manufacturing (AM). Categories of AM methods are shown in accordance with internationals standards. In order to take advantage of any new technology, a thorough understanding of its capabilities and limitations is crucial. This chapter covers...
Chapter
Nondestructive testing (NDT) is a broad discipline comprising of a range of technologies for the identification of flaws (cracks, pores, inclusions, etc.) in manufactured parts without damaging them. Traditionally, NDT is used to identify defects for a pass/reject decision, either for manufactured parts or for large industrial parts in use (e.g., p...