Exeter, United Kingdom
Exeter, United Kingdom

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Agency: GTR | Branch: EPSRC | Program: | Phase: Research Grant | Award Amount: 534.06K | Year: 2014

The development of implantable prosthetics has revolutionised medicine. Where joint injury or destruction would once have once significantly reduced quality of life, to the detriment of a patients fitness and health, we can now almost fully restore function. The manufacturing methods used for the production of prosthetics are quite crude and often require the casting of metal into a mould before finishing by hand. As a consequence they are usually made to only a few different sizes and the resulting structures must be made to fit by the surgeon. This is acceptable for the majority of patients who require joint replacement, but there are some medical conditions that require very irregularly shaped (customised) structures to enable an adequate repair. For example, bone cancers often require extensive cutting away of the bone and this can leave a very large and irregular defect. Similarly the bone structure of the face and skull is very specific to an individual and when bone must be removed, again due to cancer or following physical damage. To restore physical appearance, it would be best if a clinician were able to generate a plate that could allow them to replace like for like. In this project, we will refine an Additive Layer Manufacturing (ALM) technology called selective laser meeting (SLM) to allow us to produce implants that are individual to a patient. These technologies use lasers to fuse powder and create a three dimensional object in a layer by layer fashion. By taking three dimensional images (MRI and CT) from a patient, operators can design structures that will be able to directly replace tissue with the optimum shaped implant. In this project, we will work with doctors from the Royal Orthopaedic Hospital, Queen Elizabeth Hospital and the Royal Centre for Defence Medicine to develop a process that we hope will eventually allow these clinicians to produce implants in their own hospitals or even on the front-line of a conflict and enable better treatment for their patients. As well as allowing the production of complex-shaped parts, ALM has another significant advantage over casting in that it allows the production of very complex porous structures within a material. This means that we can modify the physical properties of the material by incorporating holes or structured porosity into the structure. These holes can be sealed from the surface of the prosthesis, or can be linked to the surface using a network of even narrower holes. We would like to explore the use of this added manufacturing capability to make prosthetics with a very closely defined internal structure that is completely interconnected. A second, cement like, material can then be injected into the pore structure and will harden in place. This second phase can be used to modify mechanical properties or could be used as a carrier for drugs that may stop infection or help the tissue to heal. It is hoped that this modification could help us eliminate implant-based infections, which is the leading cause of failure following prosthetic implantation.

Agency: Cordis | Branch: FP7 | Program: BSG-SME | Phase: SME-1 | Award Amount: 1.20M | Year: 2009

The use of computer tomography (CT) imaging is steadily increasing in the ever growing bone implant/surgery and tissue engineering market, although commercial exploitation of CT data for structural design purposes is still based on trial-and-error approaches. This is because X-ray attenuation information is reduced to geometric grey level evaluation. However, on the academic stage, a transnational team of highly esteemed applied physicists, material scientists, engineering mechanicians, and mathematicians has recently pioneered concepts for extraction of chemical information from CT, and of its conversion, via micromechanics laws, into object specific, inhomogeneous and anisotropic material properties. We here propose R\D activities to substantiate this cutting-edge knowledge into unparalleled, highly reliable simulation tools for structural design purposes. Most of the work load related to these R\D activities will be carried by the RTD partners, which will (upon reimbursement) transfer the simulation tools to four highly innovative SME partners covering all aspects of the bone biomaterial/surgery preplanning market, being leaders in the fields of biomaterial production, of micro and nano-CT scanner development, of image-to-geometry/mesh conversion, and of Finite Element simulation technologies. As a result of the R\D activities being carried out in close cooperation with SMEs, the latter will be, upon completion of the project, the owners of ready-to-use software packages tailored to SME-specific needs, with rapid time-to-market characteristics. The uniqueness of these products will tremendously improve the strategic market positions of the SMEs, which are expected to generate annual revenues being already multiples of the singular EC contribution when just considering the submarkets of preplanning dental/orthopaedic surgery and bone tissue engineering research. This will trigger SME growth rates exceeding 30%, both in turnover and employment.

Agency: Cordis | Branch: FP7 | Program: CSA-SA | Phase: SiS-2010- | Award Amount: 1.23M | Year: 2011

The objective of the project is to use art to communicate emotions related to the understanding of nature and to stimulate students create artistic initiatives able to demonstrate commonalities of artistic and scientific fascination. The objective will be pursued according to two strictly related aspects: 1)produce artistic works based on scientific phenomena at a professional level; 2)stimulate students of EC schools to produce their own works and to organize an international competition to prize the best ones. (We consider this a form of very deep and long lasting interactive action that we prefer to the sometimes superficial and ephemeral interactive processes available in some popularization science exhibitions). Practically we intend to realize artistic events based on scientific issues per each of the following artistic disciplines: 1)Modern dance 2)Cinema 3)Contemporary art 4)Imaging 5)Literature The produced art work will be exploited in a double way: a)By presenting them in live events in the different countries involved in the project addressing not only the targeted category of persons (high school students (15-18 years), but also the general public; b)By organizing a competition among the EU high school students for each of the 5 considered discipline (with a consequent interactive process involving potentially thousands of students). The consortium includes several scientists, artists, art critics, film directors, actors, musicians and specialists in science popularization, who will work together to achieve the goals synthetically above reported. The activities will be coordinated by the project leader who is, at the same time, a well known scientist and a person active since long time in several artistic activities. Universities, research institutes, dance schools, museums, theatres will be involved, together with the famous European Synchrotron Radiation Facility which hosts every year thousands scientists, including Nobel price winners.

Agency: Cordis | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-2011-ITN | Award Amount: 3.84M | Year: 2012

The objective of this ITN is to develop the next generation methods integrating numerical simulation and geometric design technology. Currently, geometric design and simulation is based on different geometry representation hampering the effective design of Engineering structures, materials and components. Isogeometric analysis developed recently tries to remove those drawbacks by integrating CAD shape functions, in particular NURBS, in numerical analysis. On the other hand, not all design models are based on CAD designs. In many applications, the geometric description is obtained from other data, e.g. CT-scans or surface models or point clouds generated by laser scanners, e.g. from clays models for automotive design. A classical application is reverse engineering, material characterization or computer supported materials design. The automatic image segmentation of CT-scans and the subsequent creation of the design model is far from simple. Voxel-based finite element analysis is commonly used in such applications The analysis of an engineering object based on the simulation of some physical system usually requires the generation of a computational basis for a partial differential equation. Typically this discretization is based on a geometric mesh model or a set of nodes which determines local basis elements. The properties of these basis elements in relation to the partial differential equation are crucial to obtain good analysis results. Depending on the system simulated, different types of basis elements are required. In this ITN, we aim to provide a general framework of unifying pre-processing/design in general with numerical analysis. The framework will be applied to the most common and popular methods employed in pre-processing.design and analysis, i.e. spline-based basis functions (NURBS, T-splines, etc.), voxel-based finite elements, polynomial (standard) and spline-based finite elements and extended finite element and meshfree methods.

Agency: Cordis | Branch: FP7 | Program: BSG-SME | Phase: SME-1 | Award Amount: 1.35M | Year: 2010

The three-dimensional optical measurement of objects and surfaces is a state of the art technology in many industries like the automotive or medical sector. It is used for the reverse engineering process, the quality management and new fields of application like inspection and accelerated development process. The total cost of such a system ranges from 25T to 200T making it almost not affordable for SMEs which can therefore not benefit from this technology compared to LEs. White light hand-scanner systems which do not require a high-cost position tracking system are becoming more important having high potential for a boost in this market. The accurate and easy creation of three dimensional images of real objects is achieved by sequential measured surface scans. Existing 3D white light scanners suffer from complex manual post-processing due to inaccurate measured data and technical limited number of surface scans. The goal is to create a system with remarkable advantages compared to existing scanning devices. A method and technology for the continuously real-time 3D white light scanning will be developed. The innovation will focus on the ability of full automated accurate processing of the surface data.

Fritsch A.,Vienna University of Technology | Hellmich C.,Vienna University of Technology | Young P.,University of Exeter | Young P.,Simpleware Ltd.
Journal of Applied Mechanics, Transactions ASME | Year: 2013

There are lots of ceramic geological and biological materials whose microscopic load carrying behavior is not dominated by bending of structural units, but by the three-dimensional interaction of disorderedly arranged single crystals. A particularly interesting solution to capture this so-called polycrystalline behavior has emerged in the form of self-consistent homogenization methods based on an infinite amount of nonspherical (needle or disk-shaped) solid crystal phases and one spherical pore phase. Based on eigenstressed matrix-inclusion problems, together with the concentration and influence tensor concept, we arrive at the following results: Young's modulus and the poroelastic Biot modulus of the porous polycrystal scale linearly with the Young's modulus of the single crystals, the former independently of the Poisson's ratio of the single crystals. Biot coefficients are independent of the single crystals' Young's modulus. The uniaxial strength of a pore pressure-free porous polycrystal, as well as the blasting pore pressure of a macroscopic stress-free polycrystal, scale linearly with the tensile strength of the single crystals, independently of all other elastic and strength properties of the single crystals. This is confirmed by experiments on a wide range of bio-and geomaterials, and it is of great interest for numerical simulations of structures built up by such polycrystals. © 2013 American Society of Mechanical Engineers.

Yan C.,University of Exeter | Yan C.,Huazhong University of Science and Technology | Hao L.,University of Exeter | Hussein A.,University of Exeter | And 2 more authors.
Materials and Design | Year: 2014

This paper investigates the manufacturability and performance of advanced and lightweight stainless steel cellular lattice structures fabricated via selective laser melting (SLM). A unique cell type called gyroid is designed to construct periodic lattice structures and utilise its curved cell surface as a self-supported feature which avoids the building of support structures and reduces material waste and production time. The gyroid cellular lattice structures with a wide range of volume fraction were made at different orientations, showing it can reduce the constraints in design for the SLM and provide flexibility in selecting optimal manufacturing parameters. The lattice structures with different volume fraction were well manufactured by the SLM process to exhibit a good geometric agreement with the original CAD models. The strut of the SLM-manufactured lattice structures represents a rough surface and its size is slightly higher than the designed value. When the lattice structure was positioned with half of its struts at an angle of 0° with respect to the building plane, which is considered as the worst building orientation for SLM, it was manufactured with well-defined struts and no defects or broken cells. The compression strength and modulus of the lattice structures increase with the increase in the volume fraction, and two equations based on Gibson-Ashby model have been established to predict their compression properties. © 2013 Elsevier Ltd.

Yan C.,University of Exeter | Hao L.,University of Exeter | Hussein A.,University of Exeter | Raymont D.,Simpleware Ltd
International Journal of Machine Tools and Manufacture | Year: 2012

Metallic additive manufacturing techniques, in particular the selective laser melting (SLM) process, are capable of fabricating strong, lightweight and complex metallic lattice structures. However, they still face certain process limitations such as geometrical constraints and in some cases the need for support structures. This study evaluates the manufacturability and performance of SLM produced periodic cellular lattice structures, which are designed by repeating a unit cell type called gyroid consisting of circular struts and a spherical core. The effect of unit cell size on the manufacturability, density and compression properties of the manufactured cellular lattice structures were investigated. Micro-computer tomography (CT) scan results reveal that the gyroid cellular lattice structures with various unit cell sizes ranging from 2 to 8 mm can be manufactured free of defects by the SLM process without the need of additional support structures. The Scanning Electron Microscope (SEM) micrographs show that the lattice structures made by SLM have a good geometric agreement with the original computer-aided design (CAD) models, but many partially melted metal particles are bonded to strut surfaces. The struts within the gyroid cellular lattice structures with smaller unit cell sizes have higher densities due to their shorter scan vector lengths in the SLM process. The yield strength and Young's modulus of the Gyroid cellular lattice structures increase with the decrease in the unit cell size due to the denser struts of the lattice structures with smaller unit cell sizes. © 2012 Elsevier Ltd.

Simpleware Ltd | Date: 2014-05-21

A computer-implemented image processing technique for selectively recovering the features of an original CAD model after the original CAD model has been converted to a digitized image and a new CAD model generated from the digitized image. The original boundary representation provides a template to transform the representation through processing under governance of a programmed processor so as to recover accuracy and reintroduce feature edges and feature corners as well as other detailed features to the CAD model obtained from the digitized image, e.g., to enable detailed features to be retained that would otherwise have been lost due to the lossy conversion into image space. The method operates to better ensure that reconstructed boundary vertices lie on original CAD model surfaces and feature edges and corners are recovered.

A method for preparing image data for three-dimensional printing in which a digitised (e.g. voxelized) representation of a virtual three-dimensional object (e.g. CAD model) is eroded to create an internal volume for the object. Subsequently, a vector-based surface representation of this internal volume is generated and simply combined with a corresponding vector-based surface representation of the original virtual three-dimensional object to yield a hollowed out model in a format suitable for three-dimensional printing. A microstructure may be introduced into the interior of the hollowed out model, e.g. by extracting a volume corresponding to the inverse of that microstructure from the eroded digitised representation.

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