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- EcoGrip: Developing sustainable gripper solutions for collaborative roboticsPublication . SOUSA, BRUNO MIGUEL PINTO DE; Campilho, Raul Duarte Salgueiral Gomes; Barbosa, Flávia VieiraWith the intensification of competition across industries, companies are increasingly adopting strategies to secure a competitive advantage. One such approach is the growing integration of robots into factories to optimize operations and enhance efficiency. However, this shift also results in workforce reductions. For that reason, organizations and policy makers are increasingly tasked with balancing technological advancement and the preservation of employment opportunities. This practice has led to the adoption of collaborative robots, and the development of robotic grippers for collaborative applications which are designed with safety in mind. On the other hand, a completely different topic that influences gripper design is the European Union’s Ecodesign for Sustainable Products Regulation. This regulation aims to reduce the environmental impact of products during the entirety of its lifecycle. Together, the need to enhance gripper safety for collaborative operations and the imperative to reduce their environmental impact have resulted in the demand for a new approach to the gripper development process. With this goal in mind, the objective of this dissertation is to create a methodology for the development of a collaborative robotic gripper that integrates Ecodesign principles to be employed in a practical use case. This use case proposes the creation of a vacuum based collaborative robotic gripper with four suction cups, capable of handling boxes of up to 10 kg with both 150 and 550 mm edge size. To have this capability, the gripper must be adjustable in the X-axis. In regard to weight, the gripper should weigh less than 1.5 kg and be fabricated using acrylonitrile styrene acrylate or polylactic acid. An important design characteristic was that access to the internal components of the gripper should be simple. Through the study of peer-reviewed scientific papers and also an analysis of existing gripper engineering solutions, the new methodological approach for gripper development was formulated. It encompasses six phases: Product planning, Product concept, Product architecture, Product detail, Product Prototyping, and Product testing and improvement. During the course of this work, a model is conceptualized that responds to the use case, safety, and Ecodesign requirements. The developed design is validated through numerical simulations. After validation, a physical prototype is fabricated and tested using additive manufacturing to assess its functionality and performance. The results of these tests also resulted in the creation of an improved prototype. The developed prototype was validated as a proof-of-concept, which demonstrated that Ecodesign requirements could be fully integrated into the gripper development process without compromising functionality or safety.
- Integration of piezoelectric elements in the injection moulding process for active metamaterial productionPublication . ALMEIDA, DAVID JOSÉ PEREIRA; Campilho, Raul Duarte Salgueiral Gomes; Silva, Francisco José Gomes daThe global population, subjected to continuous exposure to noise sources in the workplace, can lead to effects such as hearing loss, burnout symptoms, and overall health deterioration. In industrial contexts, vibrations, also a source of noise, not only affect human health but can also reduce equipment performance and shorten service life. Traditional solutions, such as applying insulating materials or adding mass to systems, are often insufficient to significantly reduce noise and vibration, particularly at frequencies below 1000 Hz. Moreover, these approaches may also compromise equipment efficiency due to added mass and negatively affect aesthetics. Acoustic metamaterials have emerged as a superior alternative, as they can create a stop-band effect, are lighter, and, when incorporating piezoelectric elements, can be actively tuned to target specific frequency ranges. Nevertheless, metamaterials are commonly manufactured through additive manufacturing processes, which restricts their use in large-scale applications. The present study addresses this limitation by developing an approach to over-mould piezoelectric elements using injection moulding to produce active metamaterials. Through numerical simulations, a piezoelectric element was selected with the optimal dimensions (36 x 20 x 0.22 mm3) to achieve the best possible vibrational performance when over-moulded in the hosting part. Following an iterative process, a set of injection tests using acrylonitrile butadienestyrene (ABS), was conducted, successfully fulfilling the objective of over-moulding the piezo and its electrical components using a validated solution that mimics the two-shot injection moulding process. Furthermore, it was determined that polymer shrinkage is the primary factor causing defects in the piezo, as the contraction forces induce a bending curvature, ultimately leading to its fracture. The two-shot injection solution mitigated this behaviour due to the piezo’s full encapsulation, which prevents the piezo from bending under shrinkage. From the set of tests performed, it was concluded that injection pressure, cooling time, and melting temperature do not determine the survival of the piezo during cavity filling. Instead, the decisive factor is the mould design, which ensures stabilisation during injection, together with the two-shot injection concept.
- Estratégias de melhoria de hidrofobicidade de um filme polimérico à base de amido reforçado com fibras de casca de castanhaPublication . CARVALHO, LARA ADRIANA FERREIRA; Matos, Cristina Maria Fernandes Delerue Alvim de; Vieira, Elsa Marisa FerreiraOs filmes à base de amido são uma alternativa biodegradável aos plásticos convencionais. Contudo, devido à sua natureza hidrofílica, enfrentam algumas limitações significativas, o que compromete a sua aplicação em embalagens alimentares. Neste contexto, o presente estudo teve como principal objetivo otimizar a formulação de um filme à base de amido, previamente reforçado com fibras de casca de castanha, através da implementação de estratégias sequenciais para aumentar a sua hidrofobicidade. Numa primeira fase, avaliou-se a reticulação da matriz de amido com ácido cítrico. Apesar de não se terem observado diferenças estatisticamente significativas nas propriedades de interação com a água, verificou-se que a formulação com 3% (p/p) de ácido cítrico apresentou a combinação mais favorável de propriedades mecânicas. Posteriormente, explorou-se a incorporação de óleos vegetais (milho e soja), contudo, apesar de uma ligeira melhoria na resistência à humidade, descontinuou-se esta abordagem devido ao impacto negativo e acentuado na transparência dos filmes, um atributo considerado essencial. A terceira e principal estratégia consistiu na incorporação de nanopartículas de óxido de zinco (nZnO) e na substituição parcial das fibras de casca de castanha por nanofibras de pampa grass, recorrendo-se a um Modelo de Superfície de Resposta (MSR) segundo um desenho experimental Box-Behnken (BBD). Desta análise, resultou uma formulação ótima, composta por 44% de glicerol, 2% de nZnO e uma mistura de 83% de nanofibras de pampa grass e 17% de fibras de casca de castanha, com melhorias face ao filme de controlo: um aumento de 82,6% na tensão de rutura e reduções de 32,3% no teor de humidade e de 31,3% na solubilidade em água. Apesar das melhorias, a aplicação do filme ótimo na conservação de alimentos perecíveis, como queijo e carne, com teores respetivos de humidade de 40% e 75%, revelou que, embora superior ao controlo, o seu desempenho como barreira à humidade ainda se mostra insuficiente quando comparado com o plástico convencional (PET), resultando na desidratação dos alimentos e na perda de flexibilidade do filme. De uma forma geral, concluiu-se que, embora as estratégias adotadas tenham melhorado eficazmente as propriedades do filme, a sua aplicação em alimentos com elevada atividade de água permanece um desafio.
- Analysis of wood plywood joints in large pallets using numerical finite element analysisPublication . ROCHA, RAFAEL RODRIGUES; Campilho, Raul Duarte Salgueiral GomesThe global packaging industry has evolved toward more sustainable and efficient solutions, particularly in logistics and goods transportation. Wooden pallets remain dominant in freight handling due to their structural simplicity, low cost, and compatibility with various transport systems. However, industry trends demand optimization of these structures for sustainability, cost-effectiveness, and adaptability to custom sizes. This is particularly relevant for companies like NEFAB Portugal, which provide industrial packaging solutions for sectors such as automotive and telecommunications. As the demand for customized pallet sizes grows, there is an increasing need to analyse the mechanical performance of large dimensions pallets created by joining wooden beams. Actually, the use of adhesives and mechanical joints in pallet construction raises key questions regarding strength, cost, and durability under real-world loading conditions, which emphasis the need for structural verification. The primary aim of this dissertation is to study and compare seven different joint geometries for wooden beams used in pallet structures. These configurations were tested experimentally and simulated using Finite Element Analysis (FEA) to identify the best performing design. The research involved material characterization, manufacturing of joint specimens, static mechanical testing, and validation through numerical models. The joints were also assessed based on fabrication complexity, environmental sustainability, and cost-effectiveness. This comprehensive study supports NEFAB Portugal in optimizing future pallet designs, contributing to a more sustainable and efficient packaging strategy. The results show that specific joint geometries, particularly those combining adhesives with mechanical reinforcements, provide superior load-bearing capacity and cost efficiency compared to conventional methods.
- Industry 5.0 and Operational Excellence: A Comparative Study between Portugal and Poland with a Conceptual Framework for European SMEsPublication . PAIXÃO, DUARTE JORGE CUNHA; Sá, José Carlos Vieira de; Ulewicz, Robert MironThis dissertation aims to develop a conceptual framework that integrates Industry 5.0 principles with structured models of Operational Excellence, providing organizations with a clear, humancentred path towards next-generation quality and performance. Based on an extensive literature review, the study consolidates fragmented works, addressing technologies such as IoT, Big Data, AGVs, Cobots, and Digital Twins, defining four critical areas for the transition to Industry 5.0 — humans, mass customisation, supply chain resilience, and circular economy — and synthesises barriers to implementation, such as financial constraints, technological compatibility, workforce skills, trust, and energy consumption. The research addresses two central research questions: how SMEs in Portugal and Poland currently implement and perceive the concepts of Industry 5.0 and Operational Excellence, and how Industry 5.0 tools and Operational Excellence models can establish synergy to achieve sustainable growth, competitive advantage, and a better triple bottom line in SMEs. To validate the FIVE-X conceptual framework, semi-structured interviews and visits were conducted at 24 companies (11 Portuguese and 13 Polish), involving experts in production, quality, and digital transformation. The analysis, conducted in WebQDA, used 55 codes applied to 725 excerpts, totalling 2,305 occurrences, reflecting comparable priorities between the two countries: Portuguese companies reveal greater readiness to adopt advanced technologies and structured models of excellence, while Polish companies emphasise areas of transition more aligned with sustainability and mass customisation. A cross-analysis with NAIADE generated seven plausible transition scenarios, ranked by a technical assessment with 20 criteria and by social preferences of experts, revealing differences between theoretical and practical perspectives. The study also identified sectoral alignments, with energy services and industrial solutions more dependent on advanced technologies, while ceramics and textiles benefiting from human or financially restrictive approaches. These conclusions provide two key insights: (i) the existence of shared priorities enables a universal framework, (ii) but its application requires generic steps that allow companies to set priorities according to their strategic vision. Additional thematic coding validated the four hypotheses of the conceptual framework, each supported by more than 86% of responses, leading to the refinement and extension of the FIVE-X Framework. It is concluded that integrating the pillars of Industry 5.0 with structured methodologies of excellence offers practical and adaptable guidelines for sustainable industrial transformation, although its current application remains geographically limited and lacks validation in broader contexts.