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Piezoelectric co-axial filaments produced by co-extrusion of poly(vinylidene fl...

Documento submetido para revisão pelos pares. A publicar em "Journal of applied polymer science". ISSN 1097-4628. Article first published online: 3 APR 2014 : http://onlinelibrary.wiley.com/doi/10.1002/app.40710/abstract. DOI 10.1002/app.40710. ; The development of new thermoplastic polymer-based piezoelectric sensors with filament geometry is described. These filaments are appropriate for integration into tex...

Processing and electrical response of fully polymer piezoelectric filaments for...

This paper describes the production and characterization of novel geometries for piezoelectric products with a large potential in the design and implementation of flexible sensors produced at low cost and high rates. In particular, the filament geometry, appropriate for integration into textiles, is analyzed. Piezoelectric filaments producing electrical signals under bending or traction stress, thus acting as m...

Xaires (Macedo de Cavaleiros): uma primeira aproximação artefactual

Deposition of conductive materials on textile and polymeric flexible substrates

This paper describes the study, analysis and selection of textile and similar materials to be used as flexible substrates for thin conductive film deposition, in the context of integrating electronics into textiles. Kapton® polyimide was chosen as reference substrate material, was characterized regarding mechanical and electrical properties and was used as a basis for a comparison with several textile substrate...

Wearable biopotential measurement using the TI ADS1198 analog front-end and tex...

The development of mobile systems for monitoring bioelectric signals outside a hospital environment involves many challenges that do not arise when it is in a controlled environment, like a hospital. The dimensions of these systems are an important factor to consider in order to facilitate their use without interfering with the daily activities of individuals. The purpose of this work is the implementation of a...

Three layer polymer piezoelectric filaments produced by extrusion

Poly(vinylidene fluoride) (PVDF) is extensively studied due to its piezo-, pyro- and ferroelectric properties. These properties enable the use of this polymer in a number of applications either as sensor or actuator. PVDF is a semi-crystalline polymer and can crystallize in four different crystalline phases, called α, β, γ and δ. The β-phase presents the most interesting electroactive activity. These properties...

Properties and processing by extrusion of electrically conductive multilayer fi...

This work describes the production and characterization of three-layer piezoelectric filaments using two different electrically conductive polymers. The filaments were produced in a filament extrusion line, equipped with a coextrusion die that enabled a coaxial arrangement for a three-layer filament. For the inner and outer layers two different electrically conductive compounds were used, and the middle layer w...

Coextrusion of multilayer piezoelectric tape

Materials with piezoelectric properties are defined as materials that produce an electrical potential when subjected to mechanical stress (sensor function) or, in the opposite sense, produce mechanical work when subjected to an electrical field (actuator function). Poly(vinylidene fluoride), PVDF, is a polymer with a high piezoelectric coefficient, and thus is often used in the above mentioned applications. Th...

Extrusion of poly(vinylidene fluoride) recycled filaments : effect of the proce...

This study analyses the possibility of reprocessing used poly(vinylidene fluoride), PVDF, maintaining the main properties critical for its use in piezoelectric sensor/actuator applications. The influence of multiple reprocessing cycles of PVDF on crystallinity and ß-phase content fundamental for its electroactive behaviour, was studied. Nine reprocessing cycles were completed and it was found that the material ...

Acoustics of Modern and Old Museums

The goal of this study is to acoustically characterize typical modern and old museums. Modern museums can easily have a bad acoustic behavior due to the widespread use of very smooth and reflective coatings, hard floors, high-ceilings and very expressive volumes. This situation is not usually seen in "old" museums. Acoustic analyses of two case-studies (the 1999 Contemporary Art Museum of Serralves and the Nati...