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Journal Article
Castro, D., P. Jaeger, A. C. Baptista, and J. P. Oliveira, "An Overview of High-Entropy Alloys as Biomaterials", Metals, vol. 11, pp. 648, 2021.
Honnet, C., H. Perner-Wilson, M. Teyssier, B. Fruchard, J. Steimle, A. C. Baptista, and P. Strohmeier, "PolySense: Augmenting Textiles with Electrical Functionality using In-Situ Polymerization", Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems, 2020.
Contreras, J., J. Tornero, I. Ferreira, R. Martins, L. Gomes, and E. Fortunato, "Simulated and Real Sheet-of-Light 3D Object Scanning Using a-Si:H Thin Film PSD Arrays", Sensors, vol. 15, issue 12, pp. 29938-29949, 2015. Abstract

A MATLAB/SIMULINK software simulation model (structure and component blocks) has been constructed in order to view and analyze the potential of the PSD (Position Sensitive Detector) array concept technology before it is further expanded or developed. This simulation allows changing most of its parameters, such as the number of elements in the PSD array, the direction of vision, the viewing/scanning angle, the object rotation, translation, sample/scan/simulation time, etc. In addition, results show for the first time the possibility of scanning an object in 3D when using an a-Si:H thin film 128 PSD array sensor and hardware/software system. Moreover, this sensor technology is able to perform these scans and render 3D objects at high speeds and high resolutions when using a sheet-of-light laser within a triangulation platform. As shown by the simulation, a substantial enhancement in 3D object profile image quality and realism can be achieved by increasing the number of elements of the PSD array sensor as well as by achieving an optimal position response from the sensor since clearly the definition of the 3D object profile depends on the correct and accurate position response of each detector as well as on the size of the PSD array.

Ferreira, M., J. Loureiro, A. Nogueira, A. Rodrigues, R. Martins, and I. Ferreira, "SnO2 thin Film Oxides Produced by rf Sputtering for Transparent Thermoelectric Devices", Mater. Today-Proc, vol. 2, issue 2, pp. 647-653, 2015. AbstractDOI

The combination of high transparency and good thermoelectric properties of SnO2 can open new field of applications for the thin film thermoelectric materials. Here we report on SnO2 thin films with transmittance above 90%, resistivity bellow 10-3 Ωm and a Power Factor around 10-4 W/m.K2, for a Seebeck of -255 μV/K, at room temperature. The effect of film thickness and post-deposition annealing on the thermoelectric properties were analysed. The performances of a single layer thermoelectric device are also presented.

Marques, A. C., J. Faria, P. Perdigão, B. M. M. Faustino, R. Ritasalo, K. Costabello, R. C. da Silva, and I. Ferreira, "Stability under humidity, UV-light and bending of AZO films deposited by ALD on Kapton", Scientific Reports, vol. 9, pp. 17919, 2019.
Sousa, D. M., J. C. Lima, and I. Ferreira, "Synthesis of Cadmium Selenide Quantum Dots, Using 2, 2‐Bipyridine as a Capping and Phase Transfer Agent", ChemistrySelect, vol. 2, issue 3, pp. 1271-1274, 2017. AbstractDOI

Cadmium selenide quantum dots (CdSe QDs), were synthesized by one‐pot or water‐to‐organic phase transfer and capped with molten 2,2′‐bipyridine (bipy). The obtained CdSe QDs by the two‐step procedure, reveal average sizes of 2 nm while the one‐pot are mixed with secondary salt products and bipy and are undetectable by TEM. However the absorption peak of both CdSe QDs was at 425 nm and the emission band is centered at 535 nm, with a band width at half height of 77 nm, when excited with 425 nm light. The two‐step CdSe QDs synthesis has the great advantage of capping the CdSe QDs with bipy, forming a solid phase, which is easily stored and dispersed in most of the organic solvents. On the other hand, the one‐pot procedure requires an extra step to remove the secondary products.

Soares, P. I. P., D. Machado, C. Laia, L. C. J. Pereira, J. T. Coutinho, I. M. M. Ferreira, C. M. M. Novo, and J. P. Borges, "Thermal and magnetic properties of chitosan-iron oxide nanoparticles", Carbohydr Polym, vol. 149, pp. 382-390, 2016. AbstractDOI

Chitosan is a biopolymer widely used for biomedical applications such as drug delivery systems, wound healing, and tissue engineering. Chitosan can be used as coating for other types of materials such as iron oxide nanoparticles, improving its biocompatibility while extending its range of applications.

In this work iron oxide nanoparticles (Fe3O4 NPs) produced by chemical precipitation and thermal decomposition and coated with chitosan with different molecular weights were studied. Basic characterization on bare and chitosan-Fe3O4 NPs was performed demonstrating that chitosan does not affect the crystallinity, chemical composition, and superparamagnetic properties of the Fe3O4 NPs, and also the incorporation of Fe3O4 NPs into chitosan nanoparticles increases the later hydrodynamic diameter without compromising its physical and chemical properties. The nano-composite was tested for magnetic hyperthermia by applying an alternating current magnetic field to the samples demonstrating that the heating ability of the Fe3O4 NPs was not significantly affected by chitosan.

Soares, P. I. P., F. Lochte, C. Echeverria, L. C. J. Pereira, J. T. Coutinho, I. M. M. Ferreira, C. M. M. Novo, and J. P. M. R. Borges, "Thermal and magnetic properties of iron oxide colloids: influence of surfactants", Nanotechnology, vol. 26, issue 42, pp. 425704, 2015. AbstractDOI

Iron oxide nanoparticles (NPs) have been extensively studied in the last few decades for several biomedical applications such as magnetic resonance imaging, magnetic drug delivery and hyperthermia. Hyperthermia is a technique used for cancer treatment which consists in inducing a temperature of about 41–45 °C in cancerous cells through magnetic NPs and an external magnetic field. Chemical precipitation was used to produce iron oxide NPs 9 nm in size coated with oleic acid and trisodium citrate. The influence of both stabilizers on the heating ability and in vitro cytotoxicity of the produced iron oxide NPs was assessed. Physicochemical characterization of the samples confirmed that the used surfactants do not change the particles' average size and that the presence of the surfactants has a strong effect on both the magnetic properties and the heating ability. The heating ability of Fe3O4 NPs shows a proportional increase with the increase of iron concentration, although when coated with trisodium citrate or oleic acid the heating ability decreases. Cytotoxicity assays demonstrated that both pristine and trisodium citrate Fe3O4 samples do not reduce cell viability. However, oleic acid Fe3O4 strongly reduces cell viability, more drastically in the SaOs-2 cell line. The produced iron oxide NPs are suitable for cancer hyperthermia treatment and the use of a surfactant brings great advantages concerning the dispersion of NPs, also allowing better control of the hyperthermia temperature.

Soares, P. I. P., A. I. Sousa, I. M. M. Ferreira, C. M. M. Novo, and J. P. Borges, "Towards the development of multifunctional chitosan-based iron oxide nanoparticles: Optimization and modelling of doxorubicin release", Carbohydr Polym, vol. 153, pp. 212-221, 2016. AbstractDOI

In the present work composite nanoparticles with a magnetic core and a chitosan-based shell were produced as drug delivery systems for doxorubicin (DOX). The results show that composite nanoparticles with a hydrodynamic diameter within the nanometric range are able to encapsulate more DOX than polymeric nanoparticles alone corresponding also to a higher drug release. Moreover the synthesis method of the iron oxide nanoparticles influences the total amount of DOX released and a high content of iron oxide nanoparticles inhibits DOX release. The modelling of the experimental results revealed a release mechanism dominated by Fickian diffusion.

Matos, B., M. Martins, A. C. Samamed, D. Sousa, I. Ferreira, and M. S. Diniz, "Toxicity Evaluation of Quantum Dots (ZnS and CdS) Singly and Combined in Zebrafish (Danio rerio)", International journal of environmental research and public health, vol. 17, pp. 232, 2020.