APRÈN. Portal de la producció docent del professorat de la UPC

Ara és possible una visualització i caracterització més precisa dels materials gràcies al desenvolupament de noves tècniques d'inspecció de materials. Fins ara, s'han utilitzat projeccions i imatges bidimensionals per observar, caracteritzar i analitzar materials; tanmateix, només proporcionen una imatge parcial de la realitat. S'han aplicat tècniques de microscòpia 3D de tomografia de feix d'ions focalitzats (FIB) recents per avaluar diversos materials de carbur de tungstè i cobalt. Per tal de comprendre i millorar els models matemàtics que s'utilitzen actualment per a l'examen del material, és essencial caracteritzar ja que també es pot utilitzar per a simulacions d'elements finits. L'objectiu d'aquest projecte és aprofundir en la tècnica d'adquisició, reconstrucció i anàlisi de microestructures alhora que es contrasten les dades 3D obtingudes amb les derivades mitjançant tècniques bidimensionals. Tenir en compte l'orientació dels carburs del material i considerar si la granulació és gruixuda o fina serà essencial. S'ha demostrat que aquest mètode és una manera fiable de caracteritzar i analitzar el material genuí tal com és. Els resultats de l'anàlisi tridimensional són coherents amb els valors que s'han publicat a la literatura. També s'esmenten idees com el paràmetre mètric desenvolupat per la universitat anomenat densitat de l'esquelet de la fase aglutinant (𝜌��𝑠��𝑡��), i la reconstrucció 3D es pot utilitzar per quantificar directament característiques com l'àrea d'interfase i la superfície específica que són difícils d'adquirir a partir de l'anàlisi 2D.

Magnesium phosphate cement is a potential future substitute for current calcium phosphate cements, bone cements in general and materials capable of promoting bone formation. The objective of the project is focused on the characterization of magnesium phosphate cements obtained from magnesium oxide and sodium phosphate (Na-MPC). It is intended, on the one hand, to determine clinically relevant physical parameters (setting times and temperatures) of the already optimized cement compositions, as well as to study the setting reaction that takes place and the nature of the product formed. On the other hand, the viability of these cements in orthopedic applications will be evaluated. To do this, an existing application technique, foaming, will be tested through a design of experiments, in order to define the optimal application parameters.

Multifunctional biomaterials as energy storage devices, biosensors as well as scaffolds are of great interest due to their tunable properties. In this project, an ionically crosslinked conductive hydrogel is prepared of PEDOT:PSS and alginate to form an interpenetrating network (IPN). A ratio of 1:3 of PEDOT:PSS and alginate is used for better mechanical stability. Additionally, different types of nanomaterials (magnetic nanoparticles and carbon-based nanomaterials) are incorporated during the hydrogel synthesis to fabricate multifunctional hydrogel nanocomposites. First, the functionalized hydrogels containing magnetite exhibit low specific capacitance (Cs) (0,274 mF/g). However, a combination of an electrodeposition with Ni-Fe and an incorporation of a mixture of carbon nanotubes (CNT) and graphene into the hydrogel show both an enhancement of the Cs as well as the increase of the charging and discharging time while behaving as a pseudocapacitor. Secondly, PEDOT/Alg/magnetite hydrogel composites exhibit a high temperature sensitivity which make them good candidates as temperature sensors. Lastly, magnetite embedded hydrogel scaffolds present magnetic responsiveness when exposed to an external magnetic field, which could potentially be used to trigger cell growth and differentiation for tissue engineering applications.

Este trabajo se realizó en el marco del proyecto RevalPET UP, cuyo objetivo es encontrar nuevas formas de reciclar los residuos de tereftalato de polietileno opaco (rPET-O) para convertirlos en uno nuevo material primario. Recientemente, el PET blanco opaco se ha utilizado como material para las botellas de leche en Francia. Las botellas contienen hasta un 15% de nanopartículas de dióxido de titanio (TiO2), que protegen la leche de la degradación por los rayos UV y de la permeación de gases en la botella. Sin embargo, la presencia de este material perturba el flujo de reciclaje, ya que elimina la transparencia en caso de que se mezcle con el PET transparente, además de que sus propiedades mecánicas son insuficientes para convertirse en un nuevo material primario por sí solo. La extrusión reactiva con un agente extensor de cadena puede utilizarse para mejorar las propiedades de este material. En este trabajo se investigó la extrusión reactiva de rPET-O con el oligómero epoxídico multifuncional Joncryl ADR 4400 al 0, 1 y 1,5wt%. También se varió la velocidad de rotación de los tornillos de la extrusora de doble tornillo entre 40rpm y 80rpm. Se comprobó que la viscosidad intrínseca aumentaba al máximo con la adición de 1wt% de extensor de cadena, mientras que la velocidad de rotación no era importante para esta propiedad. La temperatura de fusión y la temperatura de cristalización disminuyeron ligeramente tras la extrusión reactiva, pero no cambiaron con la concentración de Joncryl ni con las diferentes velocidades de rotación del tornillo. La viscosidad compleja y el módulo de almacenamiento fueron los más elevados para el 1wt% de Joncryl y una velocidad de rotación de 40rpm, lo que indica que estas condiciones hicieron reaccionar más al extensor de cadena y al rPET-O. El alargamiento a la rotura fue el que más aumentó con la adición de 1wt% de Joncryl, ya que el material adquirió la capacidad de endurecerse por deformación tras el cuelgue. La adición de 1,5wt% de extensor de cadena Joncryl hizo que el material se volviera frágil.

Des de l'aparició de l'era digital, la majoria dels resultats de la investigació es publiquen en línia, i Internet s'ha convertit en la font de coneixement més gran del món. Amb el pas dels anys, el nombre de publicacions ha augmentat progressivament i la literatura sobre biomaterials no n'és una excepció. Precisament a causa del seu alt volum i la seva naturalesa heterogènia, recopilar i sintetitzar coneixements en aquest camp de forma manual és una tasca esgotadora. Les tècniques de mineria de textos, com per exemple la classificació de textos, faciliten l'organització i l'extracció d'aquestes dades. De fet, la classificació de textos és una de les tasques supervisades bàsiques en el processament del llenguatge natural, que permet assignar etiquetes o categories al text segons el seu contingut. Aquestes categories es determinen a partir d'un conjunt de documents mostra utilitzats com a entrenament (“training set”), que es classifiquen manualment prèviament. Per construir un model de classificació, s'utilitza un algorisme d'aprenentatge automàtic. Aquest algorisme analitza les dades d'entrenament (“training set”) per crear un model que pugui predir la classe d'un nou document procedent del món real. En aquest treball, es proposa un procediment de classificació de textos basat en resums d'articles, assajant-lo en resums d'articles biomèdics obtinguts de la base de dades Pubmed. El conjunt d'entrenament es compon de 3224 resums d'articles de biomaterials, i el conjunt d'estudi es compon de 477 resums d'articles sobre impressió 3D. Els objectius del projecte són dos: (1) comparar diversos models de classificació de documents de biomaterials i (2) obtenir una visió general del domini de la impressió 3D en l'àmbit biomèdic mitjançant la classificació de texts i l'extracció de dades d'un gran nombre de publicacions de recerca. El nostre classificador es va implementar utilitzant el llenguatge de programació Python. Després de provar diversos models de classificació, inclosos els models binaris i multinomials, es va aconseguir un 0,92 de precisió i un 0,89 de la puntuació F1 amb descens de gradient estocàstic (SGD) en comparació amb el tractament manual. Aquest model es va utilitzar per classificar tota la literatura d'impressió en 3D disponible de Pubmed fins a la data, que representa un total de 11,153 articles. Després es van utilitzar tècniques d'extracció de dades per recuperar informació sobre la tecnologia d'impressió 3D per a aplicacions biomèdiques. Després es van utilitzar tècniques d'extracció de dades per recuperar informació sobre la tecnologia d'impressió 3D per a aplicacions biomèdiques. Aquesta informació va permetre identificar 4 aspectes rellevants: (1) malalties que es poden tractar mitjançant aquesta tecnologia, (2) teixits o organs que es poden substituir per implants impresos en 3D, (3) biomaterials més utilitzats i (4) altres aplicacions no relacionades directament amb pròtesis o implants.

The additive manufacturing is a manufacturing technique in full expansion. However, the Fused Deposition Modelling technique is not very developed for the metals. The objective of this project is to find the best workflow which gives components with good microstructure and mechanical properties. The components are manufactured from Inconel 718 pellets composed of binder and metal powder. Two shapes have been made, one cylindrical the other in the form of a micro-tensile test specimen. The green pieces are made by the Metal Extrusion Additive Manufacturing (MEAM) technique. Then a two-step debinding was performed: a solvent debinding at 60°C in water for 15h then thermal debinding at 600°C for 1h. The sintering temperature was varied from 1200°C to 1300°C, and the sintering times were 2h30 and 4h. Increasing the sintering temperature and time both increase of density. A 10% increase of density was observed by extending the holding time by 1h30 at 1290°C: the sintering for 2h30 gives an average density of 6.22 g/cm3 and the mean density reached with a sintering for 4h00 is 7.17 g/cm3 . The observation of the microstructure by Scanning Electron Microscope (SEM) has shown the presence of an austenitic matrix presenting precipitates of high niobium composition. Moreover, when the sintering temperature is higher, the main grain size and the number of precipitates increase. With a sintering at 1290 °C for 4h00, the highest experimental hardness (335 HV) obtained reached almost 85% of the theoretical hardness of the Inconel 718 in age-hardening condition (390 HV). However, for the same sintering process, tensile tests showed a fragile behaviour of the samples. In addition, the results of the tensile tests are lower than the tensile strength expected.

In recent years, new PET bottles have appeared, totally opaque and generally white, which are used for packaging milk. These bottles contain dioxide titanium particles (TiO 2 ) in order to protect its content against UV radiation and minimize the oxygen permeation into the bottle, thus avoiding deterioration of the content. The recycling of this opaque PET (r-PET-O) is hardly compatible with current points and processes, considering the main use of this material is the production of fibres for the textile sector. This present work is included within the actions foreseen in the project “Revalorización de residuos de PET opaco en materiales de alto valor añadido (RevalPET'UP)” financed by the ERDF funds through the INTERREG V A. program. In this laboratory-scale stage of the study, the effect of a chain-extending reactive (at different concentrations) on recycled transparent PET and recycled opaque PET will be studied. For this, a physical-chemical, thermal, rheological and mechanical characterization will be carried out. It was found that the existence of TiO 2 acts as a lubricant in the system and promotes reactivity with the reactive modifying agent used. At higher concentrations of reactive agent, an interconnected TiO 2 -TiO 2 -rPET-O network is generated.

It is well known that the use of Zirconia based ceramics in the dental and orthopaedic applications have been widely studied over the last decades and literature reports a promising future for these materials to enhance its performance in the human body. But still some issues as a better osseointegration of the implant remain to be improved. The main goal of behind this research is to modify the surface of zirconia by the laser patterning technique in order to achieve a desired topography that does not compromise its mechanical integrity but at the same time enhance both the osteointegration as well as the cell adhesion. A Zirconia based ceramics specimen with a constant laser patterning already optimized has been microstructurally characterized by the focused ion beam (FIB) which leads to characterize small volumes in three-dimensions (3D). The internal defectology generated during the cold isostatic pressing as well as the once induced during the surface modification have been reconstructed in 3D with Avizo 2019.1 in order to understand the effect of the surface treatment applied on the investigated specimen and its impact on the resulting microstructure and as a consequence in their mechanical integrity. Finally, the shape as well as the geometry of the pre-existing and laser induced defects have been characterized. The preliminary data provides that the defects induced due to the laser patterning represent a total volume of 2.25 % of the sample. They also present a lenticular shape and are located in the outer layer of the sample following the laser direction. The size distribution of the defects shows a monomodal distribution for Y- and Z- axis, and a bimodal distribution for X- axis. The thickness of the affected area is not homogeneous along the sample due to the peaks and valleys that the laser generates.

The aim of this final master thesis was to modify the tribological properties at surface level in a TRIP (Transformation-Induced Plasticity) metastable steel. To this end, laser patterns were used to perform a homogeneous and controlled modification along the surface of interest of the material. Throughout this project, two main variables were studied that directly affect the final quality of the laser pattern, the laser intensity and the number of pulses, in order to be able to make homogeneous patterns with a controlled depth at the micrometric scale in the metastable steels under study. Both the microstructure and the micromechanical and tribological properties (in dry conditions and using lubricating liquid) in three different directions of lamination (longitudinal, transversal and at 45º from the direction of lamination) were evaluated by advanced characterization techniques, such as X-ray diffraction, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy, Field Emission Scanning Electron Microscopy, Focused Ion Beam, Chromatic Confocal Microscope, Atomic Force Microscope, Optic Microscope, Macro-/Micro- and Nanoindentation Testing, and Tribological Nanowear and Honing Testing. Preliminary results after a Design of Experiments show that homogeneous cone-shaped holes with controlled dimensions (25 mm diameter and a depth between 30 and 35 mm) are obtained. Likewise, a surface modification is observed with the naked eye, both at the level of laser patterns and at the compositional level, since the most superficial layer shows a yellowish color. The preliminary results of XPS show that the layer generated by the modification process is mainly made up of zinc, silicon, carbon, oxygen and nitrogen. Moreover, the nanoindentation values reveal that this layer shows hardness values of about 300-400 MPa and a rigidity of 50-80 GPa. Tribological trials show that the patterns act as reservoirs for the lubricating fluid and that the wear pattern is inferior in lubricated samples than in non-lubricated samples, in all tested directions.

In this master final thesis, the effect of the vibration-assisted ball burnishing process on the texture of a previously milled flat surface of 720 nickel alloy is analysed. It is a material of great importance in the development of key parts in the aeronautical industry. The analysis focuses on the possible influence that five factors of the process may have: the preload force, the number of passes, the linear speed of the tool, the topology of the initial surface and the strategy followed to combine the order and direction of the different passes. In order to study the effect of all these factors, an optimised design of experiments is applied to minimize the number of tests required. The acquisition of experimental data is carried out using a topographic optical sensor and are subsequently treated with specialised software that calculates the parameters that characterise the surface. The discussion of the results, which includes various statistical studies using ANOVA, focuses on the effect of burnishing on the reduction of the texture, the redistribution of the material and the possible reorientation of surface anisotropy. In addition, the results are compared when burnishing is performed with and without the assistance of vibrations. Finally, it is concluded with the combination of factors that leads to better surface topography, and the following recommended steps are established for this line of research.

Metal additive manufacturing has seen very rapid growth in recent years thanks to technological developments and research investments. Among the different additive manufacturing methods, there is the technique of Binder Jetting, which is based on the manufacture of piece layer by layer by the selective deposition of fluid binder on a bed of metallic powder. After the printing process, the pieces obtained must undergo curing and subsequent densification. This work collects the information necessary to understand this technique, in addition to being a guide on the selection of the raw material and the optimization of the process parameters. The characteristics of the powder, the properties of the binder, and the parameters of the printing process that most influence the properties of the final pieces are reviewed. Therefore, what this is about is that this work is a prelude to future projects in collaboration with HP where the metallic powder is studied and its influence on the selection of some process parameters.

Nowadays, the research of alternatives power resources has a huge importance in the society to develop new and eco-friendly systems to reduce the climate change. One good and studied option is the solid oxide fuel cells (SOFC), however, with the conventional shapes produced by using traditional processing routes, these systems present low efficiency. Within this context, one way to improve it is creating a high specific surface, and this can be achieved by means of the additive manufacturing (AM) technique. During the last decade, the AM has been the manufacturing technique of the future, thanks of the advantages that it provides; being one of the most important advantages the ability to print complex geometries like honeycomb among others. The purpose of this final Master's project is the combination of these two fields, following the work developed by myself during my Bachelor's project and some posterior work. In this case the idea is focused the project on the optimization of the resolution of the SOFC. As well as try to obtain the best feedstock composition to achieve the optimal porosity for each part. In addition, through this Master's project, a continuity on this AM field implemented within the CIEFMA group (Centre for Structural Integrity and Reliability of Materials) of the Department of Materials Science and Engineering (CEM) UPC's , can be assured, opening new applications of AM combined with the energy field. To carry out this study, the used materials were: 8Y-TZP for the electrolyte, Lanthanum gallate strontium and magnesium doped for the cathode and gadolinium oxide for the anode. This study was divided in three parts; the first one consisted in an evaluation of the particle size, by using the laser diffraction particle size technique (also known as Mastersizer) and some scanning electron microscopy micrographs, with a step to process the powder and modify the size. In a second phase the best composition was search trying different ink compositions. The main rheological parameters for the optimal ceramic pastes (G', G'') will be studied. As a final step a cylindrical sample was printed by robocasting. Afterwards, the microstructural (e.g. density, phases, etc.) and micromechanical properties (e.g. hardness, elastic modulus, fracture mechanisms, etc.) will be determined by using advanced characterization techniques, like field emission scanning electron microscopy, focused ion beam, nanoindentation among others, to assure a minimal mechanical integrity of SOFC parts.

One of the main defects that appear in the aluminium alloys obtained by casting are those caused by porosity. In this work, an Al-Si-Mg alloy used for the manufacture of high voltage connectors by the company SBI Connectors has been analysed. The main objective is to study the effect on the microstructure and mechanical properties by adding two eutectic modifying elements: sodium and strontium. Besides, the effect of two moulding processes has also been examined: sand and metallic. To study the behaviour of the alloy, different mechanical tests have been carried out: traction, hardness, and 4 points bending. Once the specimens have been tested, an exhaustive analysis of the fracture surface and the microstructure has been carried out using optical and electronic microscopy. Analysing the results, it has been possible to demonstrate how the parameter that has a greater effect on mechanical properties, rather than porosity, is the degree of modification of the eutectic, which is obtained through high cooling rates, the use of strontium as a modifier and low holding times. Likewise, it has been confirmed how strontium causes an increase in porosity, but at the same time creates a porosity of spherical morphology caused by retained gas. This allows reducing stress concentrations compared to those caused by the more irregular pores produced mainly by shrinkage. Finally, a series of improvements have been proposed in the casting process and in the subsequent heat treatment to improve mechanical properties, by increasing the degree of modification of the eutectic and improving porosity.

The use of cold atmospheric plasma in cancer treatments has been shown to be effective in creating a selectivity between healthy cells and cancer cells as a result of the contribution of reactive oxygen and nitrogen species (RONS) to the cells. Complementing it with an anti-cancer drug commonly used in current treatments, such as doxorubicin, greater effectiveness could be achieved as well as a reduction of the amount of antitumoral drug used in such therapy. In the present project, it is intended to synthesize and characterize a material composed of a hydrogel treated with cold atmospheric plasma and calcium-deficient hydroxyapatite microspheres loaded with doxorubicin, for its posterior use as dual release platform for bone cancer therapy. For this, microspheres have been successfully synthesized by emulsion of a calcium phosphate cement and microspheres have been loaded with doxorubicin. The microspheres have been added to a hydrogel composed of gelatin and alginate previously treated with cold atmospheric pressure plasma. The release of RONS and doxorubicin has been studied from the designed material to an aqueous medium. In parallel, it has been evaluated the relevance of proceeding to the coating of microspheres with polycaprolactone (PCL) by plasma polymerization and it has been studied how it influences the release kinetics of doxorubicin from the composite material. The results indicate that the composite material releases RONS and doxorubicin to the release medium.

L'aliatge NiTi, coneguda comunament com a Nitinol, és un material que presenta fenòmens de memòria de forma i super-elasticitat. Aquest aliatge ha estat molt estudiat degut a la seva capacitat per a dissipar energia en cicles de càrrega i descàrrega, un fet atractiu per a diverses aplicacions industrials i biomèdiques, com ara actuadors, stents, filferros per ortodòncia, etc. Durant els darrers anys, el seu comportament a fatiga ha estat analitzat , descobrint-se que la fractura normalment es produeix a partir de defectes pre-existents a l'interior del material (com per exemple, porus, microesquerdes, inclusions, dislocacions, etc.) o per defectes que s'indueixen durant els processos de deformació mecànica. En aquest treball final de màster es pretén observar el dany microestructural pre-existent i induït mitjançant assajos de fatiga. Per realitzar-lo s'ha utilitzat la tomografia de feix de ions focalitzats (FIB) i d'aquesta manera poder-nos centrar en el dany prop de la superfície. S'han estudiat un total de 3 mostres, una utilitzada com a referència la qual no ha sigut sotmesa a fatiga i altres dues mostres sota diferents condicions de deformació i freqüència per tal d'avaluar el seu comportament. Mitjançant la tomografia FIB s'han obtingut un conjunt d'imatges 2D i posteriorment, mitjançant el software AVIZO 2019.1, s'ha realitzat la reconstrucció 3D de cada una de les mostres i s'ha procedit a quantificar diferents paràmetres microstructurals, tals com: la fracció volumètrica de cada una de les fases, porositat, inclusions i efectes de rugositat, íntimament relacionats amb la transformació de fase. Finalment, els paràmetres microstructurals (principalment la porositat i les inclusions) obtinguts amb la reconstrucció 3D, s'han quantificat mitjançant la utilització d'un mètode estadístic proposat per Ulm and Constantinides, per tal d'avaluar la seva incidència en el comportament a fatiga. De forma general, s'observa un increment en la mida dels defectes (principalment rugositat) a nivell superficial (els primers 100 nm) que podrien ser deguts a la transformació de fase austenita-martensita.

Vacutrem, S.A, is a heat treatment company which intends to implement a linear furnace for the continuous artificial aging of aluminum alloys. The objective of the project is to determine the main parameters (furnace temperature and speed of the conveyor belt) of the annealing furnace. Simultaneously, to study the economic profitability of the furnace to determine the viability of the project. One of the most recurrent products in Vacutrem has been selected for this study. An optimization process has been established to select the optimal treatment for that product. There are several minimum values required for the mechanical properties of the component. To obtain the optimal treatment, a total of 35 aging variations are carried out, keeping the solubilization stage constant and changing the maturation time and temperature. For each treatment, three Brinell hardness tests and three tensile tests are applied. With the results obtained, the aging curves are elaborated for each mechanical property, which the optimal treatment will be selected with. Visualization of the microstructure by optical microscopy is carried out to ensure a successful aging treatment. Once the optimal treatment is established, the values of the main parameters of the maturation furnace are determined. With these values an estimation of the productive capacity and the economic benefits of the installation is made. Finally, through the productive capacity, the economic variables NPV and IRR are calculated to determine the viability of the project.

Los carburos cementados WC-Co (comúnmente referidos como metal duro) son materiales compuestos cuya aplicación ha ido incrementando de forma exponencial, desde su introducción hace ya casi un siglo, en distintos ámbitos industriales. En gran medida, ello es debido a la excelente combinación de propiedades mecánicas y tribológicas que estos materiales ofrecen. Sin embargo, el rendimiento de componentes y herramientas de metal duro puede experimentar roturas inesperadas, bajo la aplicación de cargas tanto monotónicas (fractura) como cíclicas (fatiga), y ello es fuertemente dependiente de la microestructura del material. En este contexto, el principal objetivo de este trabajo es identificar, analizar y entender correlaciones básicas que existen entre distintos parámetros microestructurales y las propiedades mecánicas que presentan estos materiales. Para ello, se analiza una extensa y detallada base de datos recopilada a partir de tres tesis doctorales realizadas, en el seno de grupo de investigación CIEFMA, a lo largo de los últimos 20 años. Estos datos incluyen calidades de metal duro con un amplio abanico de características microestructurales - en términos de contenido de la fase ligante metálica, así como del tamaño medio de las partículas cerámicas -, y en consecuencia, de propiedades mecánicas. A lo largo del trabajo se presta especial atención a las propiedades que describen el comportamiento a fractura y fatiga de los carburos cementados. La información y el análisis crítico realizado es de gran utilidad para poder estimar y predecir la integridad mecánica de piezas fabricadas de metal duro, de cara a incrementar su rendimiento, así como prolongar su vida útil.

Due to the global impact of the SARS-CoV2 virus, the medical services of many countries have been overwhelmed by the lack of resources to deal with the pandemic. The symptoms caused by COVID-19 affect the respiratory system of patients. In this work, a mechanical device has been designed for the purpose of automating a manual resuscitator based on a silicone oval. In order to control the amount of air supplied to the patient, the system consists of software that receives feedback from a pressure and a flow sensor. In the content of the design, special amendment is made to the importance of the correct selection of materials using the Ashby methodology in some components subject to specific requirements according to current legislation. The prototype has undergone conformity validation processes in order to begin the clinical trials required to obtain the certification and consent to the sale of the devices. The first trial was performed in animals and the second in patients. Finally, the work includes an analysis of the environmental impact and life cycle in terms of energy consumption, transport and materials.

Due to the increase of bone diseases caused by the ever-aging population, new biomaterials destined for bone regeneration need to be developed. New methods, such as robocasting are gaining interest as they allow printing of self-setting calcium phosphate (CaP) scaffolds. The control of the architecture by robocasting together with the control of composition using CaPhave resulted in the development of materials very similar to the structure and composition of natural bone. However, the mineral phase in bone is a calcium phosphate (hydroxyapatite) enriched with many ionic substitutions fundamental for bone growth. This project will focus on the incorporation of four different ions (Mg, Sr, Zn and Si) in hydroxyapatite scaffolds produced by robocasting. The incorporation of these ions is explored using two strategies, by incorporating the ion of interest during a post-printing treatment and by incorporation the ion of interest directly in the ink formulation. Different characterization techniques have been used to determine ion incorporation: X-ray powder diffraction, elemental analysis by energy-dispersive X-ray, Raman spectroscopy and electron diffraction by transmission electron microscopy (TEM). Among them, the most successful technique has been TEM. The results show that, in general, ion doping post printing is more successful than changing the ink formulation. In addition, ion concentration had a strong effect on scaffold purity and the degree of ion-doping.