Fabrication of low electrical percolation threshold multi-walled carbon nanotube sensors using magnetic patterning

Soft robotics is an expanding area with multiple applications; however, building low-cost, soft, and flexible robots requires the development of sensors that can be directly integrated into the soft robotics fabrication process. Thus, the motivation for this work was the design of a low-cost fabrication process of flexible sensors that can detect touch and deformation. The fabrication process proposed uses a flexible polymer nanocomposite with permanent magnets strategically placed where the conductive electrodes should be. The nanocomposite is based on poly(dimethylsiloxane) (PDMS) and multi-walled carbon nanotubes (MWCNTs). The MWCNT contains ferromagnetic impurities remaining from the synthesis process, which can be used for magnetic manipulation. Several electrode geometries were successfully simulated and tested. The magnetic patterning was simulated, allowing the fabrication of conductive patterns within the composite. This fabrication process allowed the reduction of the electrical resistivity of the nanocomposites as compared to the composites with homogeneous MWCNT dispersion. It also allowed the fabrication of piezoresistive and triboelectric sensors at MWCNT concentration as low as 0.5 wt.%. The fabrication process proposed is flexible, allows the development of sensors for soft robotics, as well as monitoring large and unconventional areas, and may be adapted to different mould shapes and polymers at low cost.This research is part of the PhD project at the Doctoral Program in Advanced Materials and Processing—FEUP. We would like to thank CeNTI for providing resources (labs, equipment and consumables) to perform the fabrication and characterisation of the samples. The authors thank CEMUP for expert assistance (Rui Rocha) with SEM-EDS. IPC acknowledges the support of FCT through National Funds References UIDB/05256/2020 and UIDP/05256/2020

QUÍMICA AMBIENTAL NA ESCOLA: EDUCAÇÃO AMBIENTAL NO ENSINO DE CIÊNCIAS

O projeto Química ambiental na escola: educação ambiental no ensino de ciência tem como objetivo principal introduzir conteúdos de química aplicados à sustentabilidade ambiental. O projeto consiste na elaboração e execução de experimentos que auxiliam no desenvolvimento dos conteúdos curriculares no ensino fundamental, por meio de práticas voltadas a compreensão de temas importantes para conscientização ambiental. As atividades e experimentos foram realizadas com alunos do 6° ano do ensino fundamental com o objetivo de propor experimentos que valorizem o conhecimento científico e os correlacione com atividades do cotidiano. Como resultados preliminares foi possível observar que a utilização de experimentos que podem ser considerados mais avançados, como: adsorção, coagulação e destilação simples, podem ser adotados para facilitar a compreensão dos conteúdos: misturas homogêneas e heterogêneas e estados físicos da água, relacionando-os com tratamento de águas contaminadas e ciclo da água. A utilização de materiais específicos de laboratório (principalmente as vidrarias) contribuíram para estimular o interesse dos estudantes durante à prática, demonstrando a importância de aproximar as Instituições de Ensino Superior à Educação Básica com a finalidade de amenizar estas carências

Finely tuned fiber-based porous structures for bone tissue engineering applications

info:eu-repo/semantics/publishedVersio

Finely tuned fiber-based porous structures for bone tissue engineering applications

[Excerpt] Scaffolds developed for bone tissue engineering (TE) must possess specific structural properties to allow neo-tissue formation and integration within the material[1]. Several polymeric systems and processing methodologies have been proposed to develop bone TE scaffolds. Nevertheless, the so far proposed strategies do not fulfil all the requirements for effective bone regeneration. Textile technologies have recently emerged as an industrial route for producing more complex fibre-based porous scaffolds[2]. Silk fibroin (SF) from Bombyx mori has already proved to be a good biomaterial for bone TE[3]. SF-based structures are known for the impressive mechanical properties and biocompatibility, which meet the basic requirements for developing bone TE scaffolds[4],[5]. [...]Portuguese Foundation for Science and Technology (FCT) for the project TISSUE2TISSUE (PTDC/CTM/105703/2008); Investigator FCT program IF/00423/2012 and IF/00411/2013

New biotextiles for tissue engineering : development, characterization and in vitro cellular viability

This work proposes biodegradable textile-based structures for tissue engineering applications. We describe the use of two polymers, polybutylene succinate (PBS) proposed as a viable multifilamentand silk fibroin (SF), to produce fibre-based finely tuned porous architectures by weft knitting. PBS is here proposed as a viable extruded multifilament fibre to be processed by a textile-based technology. A comparative study was undertaken using a SF fibre with a similar linear density. The knitted constructs obtained are described in terms of their morphology, mechanical properties, swelling capability, degradation behaviour and cytotoxicity. The weft knitting technology used offers superior control over the scaffold design (e.g. size, shape, porosity and fibre alignment), manufacturing and reproducibility. The presented fibres allow the processing of a very reproducible intra-architectural scaffold geometry which is fully interconnected, thus providing a high surface area for cell attachment and tissue in-growth. The two types of polymer fibre allow the generation of constructs with distinct characteristics in terms of the surface physico-chemistry, mechanical performance and degradation capability, which has an impact on the resulting cell behaviour at the surface of the respective biotextiles. Preliminary cytotoxicity screening showed that both materials can support cell adhesion and proliferation. These results constitute a first validation of the two biotextiles as viable matrices for tissue engineering prior to the development of more complex systems. Given the processing efficacy and versatility of the knitting technology and the interesting structural and surface properties of the proposed polymer fibres it is foreseen that the developed systems could be attractive for the functional engineering of tissues such as skin, ligament, bone or cartilage.The authors are grateful to the Portuguese Foundation for Science and Technology (FCT) under the programs POCTI and/or FEDER (post-doctoral fellowship to Ana L Oliveira, SFRH/BPD/39102/2007), and the project TISSUE2TISSUE (PTDC/CTM/105703/2008), founded by FCT agency

Truly form-factor–free industrially scalable system integration for electronic textile architectures with multifunctional fiber devices

Funding Information: This work was supported by the European Commission (H2020, 1D-NEON, grant agreement ID: 685758). J.M.K. and L.G.O. acknowledge the support from the U.K. Research and Innovation (EPSRC, EP/P027628/1). We thank Y. Bernstein and J. Faulkner for helping with grammar check. Funding Information: Acknowledgments Funding:ThisworkwassupportedbytheEuropeanCommission(H2020,1D-NEON,grant agreementID:685758).J.M.K.andL.G.O.acknowledgethesupportfromtheU.K.Researchand Innovation(EPSRC,EP/P027628/1).W ethankY .BernsteinandJ.Faulknerforhelpingwith grammarcheck.Authorcontributions:S.L.andJ.M.K.conceivedtheproject.S.L.,L.G.O.,P .B., R.Martins,andJ.M.K.supervisedtheproject.S.L.andH.L.developedF-PD.S.L.,Y .-W .L., G.-H.A., D.-W .S., J.I.S.,andS.C.developedF-SC.C.L.F ., A.S.,R.I.,P .B., andR.Martinsdevelopedfiber transistor.S.L.,H.L.,andS.C.developedF-LED.ThefiberdeviceswereevaluatedbyS.L.,H.W .C., D.-W .S., H.L.,S.J.,S.D.H.,S.Y .B., S.Z.,W .H.-C., Y .-H.S., X.-B.F ., T .H.L., J.-W .J., andY .K. The developmentofweavingprocesswasconductedbyS.L.,H.W .C., F .M.M., P .J., andV .G.C. Thelaser interconnectionwasdevelopedbyS.L.,H.W .C., K.U.,M.E.,andM.S.Thetextiledemonstrations werecharacterizedbyS.L.,H.W .C., D.-W .S., J.Y ., S.S.,U.E.,S.N.,A.C.,A.M.,R.Momentè,J.G.,N.D., S.M.,C.-H.K.,M.L.,A.N.,D.J.,M.C.,andY .C. ThismanuscriptwaswrittenbyS.L.andJ.M.K.and reviewed by H.W .C., D.-W .S., M.C.,L.G.O., P .B., E.F ., and G.A.J.A. All authors discussed the results andcommentedonthemanuscript.Competinginterests:Theauthorsdeclarethattheyhave nocompetinginterests.Dataandmaterialsavailability:Alldataneededtoevaluatethe conclusionsinthepaperarepresentinthepaperand/ortheSupplementaryMaterials. Publisher Copyright: Copyright © 2023 The Authors, some rights reserved.An integrated textile electronic system is reported here, enabling a truly free form factor system via textile manufacturing integration of fiber-based electronic components. Intelligent and smart systems require freedom of form factor, unrestricted design, and unlimited scale. Initial attempts to develop conductive fibers and textile electronics failed to achieve reliable integration and performance required for industrial-scale manufacturing of technical textiles by standard weaving technologies. Here, we present a textile electronic system with functional one-dimensional devices, including fiber photodetectors (as an input device), fiber supercapacitors (as an energy storage device), fiber field-effect transistors (as an electronic driving device), and fiber quantum dot light-emitting diodes (as an output device). As a proof of concept applicable to smart homes, a textile electronic system composed of multiple functional fiber components is demonstrated, enabling luminance modulation and letter indication depending on sunlight intensity.publishersversionpublishe

Entre consumos suntuários e comuns: a posse de objetos exóticos entre alguns habitantes do Porto (séculos XVI – XVII)

O estudo da documentação referente aos doadores da Misericórdia do Porto entre os séculos XVI e XVII, através dos objetos exóticos patentes nos respectivos testamentos e inven- tários – estes últimos provenientes de uma área que se estende de Macau ao Brasil –, permite discernir uma panóplia de objetos que mudaram a cultura material dos portuenses em contato com os territórios da expansão portuguesa. Um levantamento sistemático permitiu já rastrear, até o ano de 1699, 257 doadores, dos quais se apresentarão aqui apenas alguns, referentes a benfeitores que, não obstante possuírem bens móveis nesse âmbito, não são dados como tendo estado nos territórios de expansão transoceânica. Argumentar-se-á que essa circulação de objetos não foi exclusiva das elites nobiliárquicas, nem dos grandes centros urbanos, pelo que a sua difusão atingiu maiores proporções do que aquelas que a historiografia tem admitido até agora. A cidade em observação neste estudo – o Porto dos séculos XVI e XVII – estava longe de ser das maiores da Europa nesse período, quer em dimensão territorial, quer em efetivos populacionais, embora se situasse numa região de demografia pujante, que canalizou os seus excedentes desde cedo para a emigração interna e externa – o Entre Douro e Minho. Como teremos ocasião de verificar, fidalgos e nobres possuíam bens exóticos, mas estes encontravam-se também entre mercadores e até artesãos mais desafogados. Por outro lado, nem todos os objetos provenientes dos espaços da expansão transoceânica devem ser conotados com bens de luxo.The study of the sources referring to the donors of the Misericórdia of the city of Porto during the sixteenth and seventeenth centuries has revealed the presence of numerous exotic objects in their last wills and inventories. A survey has traced 257 donors until 1699, some of them having died in an area that extends from Macao to Brazil. Only a small number of cases shall be presented here, pertaining to benefactors who, in spite of owning objects of transoceanic origin, seem to have remained in mainland Portugal. It shall be argued that the circulation of objects has not been exclusive either to the elites of the nobility or to the large urban centres, their diffusion having been on a larger scale than what has been admitted until now. The city under scrutiny in this study – Porto during the sixteenth and seventeenth centuries – was not one of the bigger cities in this period, either in what respects to size or population, although it was located in an area of flourishing demography, that channelled its surplus population early on to internal and external emigration. Fidalgos and noblemen owned exotic goods, but these were to be found among merchants and even well-to-do artisans. On the other hand, not all objects originating from the areas of transoceanic expansion should be considered as luxury goods.info:eu-repo/semantics/publishedVersio

Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning