PVC gel based artificial muscles: Characterizations and actuation modular constructions

Polymer materials based artificial muscles have the properties of being soft, lightweight, and flexible which are similar to the nature muscular actuators. In our previous study, we have developed a contraction type artificial muscle based on plasticized poly vinyl chloride (PVC) gel and meshed electrodes. And we have improved the characteristics to make it close to the level of natural muscle. It has many positive characteristics, such as stable actuation in the air, high output, notable response rate, and low power consumption. So a wide application is expected. However, for practical applications, it is necessary to consider some specific criteria, such as performance criteria and structural criteria. In this study, we introduced the most updated properties of PVC gel artificial muscles and proposed three types of mechanical actuation modular constructions for making the PVC gel artificial muscle as a robust actuation device for robotics and mechatronics. And we tested a prototype to examine the effectiveness of the proposed modules. Finally, an analytical model for the static characteristics of PVC gel artificial muscles at different applied voltages was derived and showed good agreement with experimental results measured by a prototype of modules. (C) 2015 Elsevier B.V. All rights reserved.ArticleSENSORS AND ACTUATORS A-PHYSICAL. 233:246-258 (2015)journal articl

Proceedings of the International RILEM Conference Materials, Systems and Structures in Civil Engineering segment on Service Life of Cement-Based Materials and Structures

Vol. 1O volume II encontra-se disponível em: http://hdl.handle.net/1822/4390

International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Service Life of Cement-Based Materials and Structures

Vol. 2O volume I encontra-se disponível em: http://hdl.handle.net/1822/4341

Collagen from Marine Biological Source and Medical Applications

Collagen is the main fibrous structural protein in the extracellular matrix and connective tissue of animals. It is a primary building block of bones, tendons, skin, hair, cartilage, and all joints in the body. It is also considered a "glue" that holds the body together. Collagen production begins to slow down, and cell structures start losing their strength as we become older. Collagen supplementation is a vital way to help our body revive itself and stay youthful. Recently, collagen-based biomedical materials have developed important and clinically effective materials that have become widely acceptable. However, collagen extraction from land animal sources is complex, time consuming, and expensive. Hence, marine sources have started to be researched and have been found to be the most convenient and safest sources for obtaining collagen. Another reason for favouring these sources is due to concerns over adverse inflammatory and immunologic responses and the prevalence of various diseases among land animals that can cause health complications.Marine sources also have plenty of advantages over land animal sources: (1) a high collagen content; (2) environmentally friendly; (3) the presence of biological contaminants and toxins is almost negligible; (4) a low inflammatory response; (5) greater absorption due to their low molecular weight; (6) less significant religious and ethical constraints; (7) minor regulatory and quality control problems; (8) metabolic compatibility, among others. This huge source of marine collagen is expected to make a great contribution to marine biotechnology products and medical applications

Ligno cellulosic materials for energy storage

The constantly increasing production of a large variety of portable consumer electronic devices and the urgent request of replacement of polluting, internal combustion cars with more efficient, controlled emissions vehicles, such as hybrid or electric vehicles require the development of new reliable and safe power sources. Furthermore the continuous decrease of the oil resources and the growing concern on the climate changes call for a larger use of green, alternative energy sources, such as solar and wind. But wind does not blow on command and the sun does not always shine thus, this discontinuity in operation leads to the need of suitable storage systems to efficiently run renewable energy plants. It is evident that a new energy economy has to emerge, and it must be based on a cheap and sustainable energy supply. Lithium ion batteries, due to their high-energy efficiency, appear as ideal candidates. Although these batteries are well established commercial products, further research and development is required to improve their performance to meet the market requirements. In particular, enhancement in safety, cost, and energy density are needed. A big portion of the R&D studies are nowadays devoted to the search for optimal materials both for the electrodes and the electrolyte of the battery: as far as the electrolyte is concerned, the main goal is to replace the liquid electrolyte with a solid one. The passage to a solid configuration gives concrete promise of increasing cell safety and reliability and, at the same time, of offering modularity in design and ease of handling. Behind the optimization of existing batteries a big effort in this field is the transformation of current batteries into a light, flexible, portable device. If integrated structures containing the three essential components (electrodes, spacer, and electrolyte) of the electrochemical cells can be made mechanically flexible, it would enable these to be embedded into various functional devices in a wide range of innovative products such as smart cards, displays, and implantable medical devices. In the fabrication of such a device the exploitation of cellulose as a flexible material and at the same time the exploitation of the papermaking and printing techniques for the development of paper electrodes and electrolytes and, in a future, of the full paper battery, is under consideration. This will also open the way to a reinvestment of the paper technologies in a high tech field such as the Lithium based batteries. Paper industry, as a matter of fact, is in Europe an important manufacturing industry but the economic change together with the development of electronics highly threaten the role and the surviving of such an activity. In this context grows the urgent need for higher value-added paper products and the conversion of the traditional paper industry. Introducing paper into new products with more profitable markets is crucial. The research work of the present thesis has been developed in collaboration with the “Centre Technique du Papier “(CTP) in Grenoble (Fr). The work has been focused on the use of cellulose in the form of handsheet or microfibrils for the production of innovative electrolyte membranes to be used in Li-based batteries. Two research lines have been followed: 1- Development of composite membranes based on cellulose microfibrils and a polymeric matrix obtained by photopolymerisation of reactive oligomers. 2- Development of multilayered membranes made of cellulose handsheet and polymeric layers obtained by photopolymerisation of reactive oligomers. Both the research lines adopt the photopolymerisation process for developing the membranes. In particular using multifunctional monomers, highly cross-linked polymer membranes are obtained which can be successfully used as gel or solid polymer electrolytes. The process is fast, low cost and versatile. In fact a fully cured polymer is obtained in seconds at room temperature irradiating a proper mixture of reactive molecules and photoinitiator

Plastics: Mapping the Childhood of Modernity’s Worst Material

This dissertation, “Plastics: Mapping the Childhood of Modernity’s Worst Material,” traces plastic’s fall from grace, from its utopian interwar beginnings to the proliferative and detrital form it takes today. It seeks to answer the question of why certain plastics are regarded as disposable and finds the answer in part in children’s toys. Children’s toys are a vital manifestation to understand plastics as fit for disposal. Starting with a historical background in early plastics to set the stage for its later deterioration, it then takes three key thermoplastics – polystyrene, polyethylene, and polyvinyl chloride – and their key material interlocutors – pez dispensers, hula hoops, and pool toys – and demonstrates how the growth of the toy industry was intimately intertwined with changing ideals of consumption, obsolescence, and discard with respect to plastics. The pairing of polystyrene with foodstuffs is the subject of the second chapter, focusing on the intimate and intertwined relationship between toy and packaging. The role of the hula hoop in changing ideals of hygiene, and in the rise of the use of synthetic detergents, is the subject of the third chapter. Finally, the fourth chapter regards the role of polyvinyl chloride pool toys in teaching postwar children that plastic is a fundamentally ephemeral material, while indelibly associating it with childhood. This association meant that ultimately the material was infantilized, and one of the things that one discards when they “put away childish things.

European Union Timber Regulation Impact on International Timber Markets

The trade of illegal timber, often from illegal logging, has severe environmental, social and economic consequences. The EU’s response to this problem came with the Forest Law Enforcement, Governance and Trade (FLEGT) Action Plan, with its specific goal to end illegal logging, thereby improving sustainability of forest resources. In March 2013, an additional step was taken by implementing the EU Timber Regulation (EUTR). The EUTR requires proof of timber’s origin and legality to ensure that no illegal timber is imported into the EU. To this end the EU intends to block imports of any wood or wood product which comes from unknown sources. Certification of sustainable forest management will help EU importers minimize risk, which is an essential part of their required due diligence system. Monitoring organizations are established to assist trade associations and businesses to construct comprehensive due diligence systems. National competent authorities are designated to follow the trade of the new FLEGT-licensed timber and timber products. In the first year of the EUTR there are positive impacts, of which the most important is awareness of the disastrous situation with illegal logging, driven by exports of illegal timber. Another positive development is tropical timber exporters documenting the legality of their wood exports. Yet another positive feature is establishment of due diligence systems by EU importers. However, there are considerable problems for ensuring legal trade; for example the lack of comprehensive documentation of origin and legality. Analysis of recent trends establishes changes in the European timber trade in terms of sourcing, substitution, diversion to less-demanding countries. Short-term forecasts of market trends and changes will enable further policy assessment to achieve the objectives of improved legality in international timber markets.JRC.H.3-Forest Resources and Climat