Piezoelectric Melt-Spun Textile Fibers: Technological Overview

Piezoelectricity was first described by the Curie brothers in the late 1800s. The first materials investigated were natural materials such as bone and wood and single crystals such as quartz. Then in 1946 it was discovered that BaTiO3 ceramic can be made piezoelectric through a poling process. This was followed by the discovery of lead zirconate titanate solid solutions (PZT) in 1954 of very strong lead effects which is still widely used in piezoelectric applications. In 1969, Kawai discovered large piezoelectricity in elongated and poled films of polyvinylidene fluoride (PVDF) opening the way for research into piezoelectric polymers. Piezoelectric polymers exhibit low density and excellent sensitivity and are mechanically tough and respond better to fatigue situations. Since 2010, research has focused on the production of melt-spun piezoelectric textile fibers, with the aim of integrating sensing/energy-harvesting capabilities into smart textile structures. In this chapter, a technological overview of the state-of-the-art research into piezoelectric, melt-spun, textile fibers will be presented. The methods used for the characterization of the fibers will also be discussed with special concentration on the electric response of the fibers after mechanical stimulation

Artificial Neural Networks and Their Applications in the Engineering of Fabrics

WOS: 00036372550000

Localino T-shirt: The Real-time Indoor Localization in Ambient Assisted Living Applications

In the last decade, smart textiles have become very popular as a concept and have found use in many applications, such as military, electronics, automotive, and medical ones. In the medical area, smart textiles research is focused more on biomonitoring, telemedicine, rehabilitation, sport medicine or home healthcare systems. In this research, the development and localization accuracy measurements of a smart T-shirt are presented, which will be used by elderly people for indoor localization in ambient assisted living applications. The proposed smart T-shirt and the work presented is considered to be applicable in cases of elderly, toddlers or even adults in indoor environments where their continuous real-time localization is critical. This smart T-shirt integrates a localization sensor, namely the Localino sensor, together with a solar panel for energy harvesting when the user is moving outdoors, as well as a battery/power bank that is both connected to the solar panel and the Localino sensor for charging and power supply respectively. Moreover, a mock-up house was deployed, where the Localino platform anchors were deployed at strategic points within the house area. Localino sensor nodes were installed in all the house rooms, from which we obtained the localization accuracy measurements. Furthermore, the localization accuracy was also measured for a selected number of mobile user scenarios, in order to assess the platform accuracy in both static and mobile user cases. Details about the implementation of the T-shirt, the selection and integration of the electronics parts, and the mock-up house, as well as about the localization accuracy measurements results are presented in the paper

Mechanical Analysis of Woven Fabrics:The State of the Art

The automation and integration of processes in the textile industry is dictated by the increasing need to offer specialized products at optimum quality and low cost, satisfying at the same time the fast cycles of fashion trends or in the case of technical applications the delivery of products of high qualiy and of exact properties. Under these premises, computer engineering tools, such as computer-aided engineering (CAE) and computer-aided design (CAD), have recently gained attention. The revolutionary role of CAE and CAD tools in the textile industry is the guaranty that the final product meets the set specifications, optimizing thus the quality control procedure. Moreover, the prediction of the properties and the aesthetic features of the product before the actual fabrication can essentially benefit the textile research community [Hu and Teng, 1996]. Especially nowadays that textile materials can be used for the production of a wide range of technical products, such as reinforcements in composites for aerospace or marine applications or textiles for medical applications, the prediction of the end-product’s mechanical properties is of major importance. Furthermore, the textile raw materials are processed under low-stress conditions and it is thus reasonable to assume that the knowledge of the possible modifications introduced via the manufacturing process is necessary for the final product realization (Hu, 2004). Textiles are flexible, anisotropic, inhomogeneous, porous materials with distinct viscoelastic properties. These unique characteristics makes textile structures to behave essentially different compared with other engineering materials. Moreover, textiles are characterized by an increased structural complexity. Their properties mainly depend on a complicated combination of their structural units and their interactions. The complicated nature of the textiles’ mechanics makes them ideal candidates for a mechanical analysis using computerbased methods

Advances in Modern Woven Fabrics Technology

The importance of woven fabrics increases constantly. Starting from traditional uses mainly in clothing applications, woven fabrics today are key materials for structural, electronic, telecommunications, medical, aerospace and other technical application fields. The new application fields of the woven fabrics is directly reflected in the contents of the book. A selected collection of papers in the technological state-of-the-art builds the book “Advances in Modern Woven Fabrics Technology”. It is written by internationally recognized specialists and pioneers of the particular fields. The chapters embrace technological areas with major importance, while maintaining a high scientific level. This interdisciplinary book will be useful for the textile family member as well as for the experts of the related engineering fields. The open access character of the book will allow a worldwide and direct access to its contents, supporting the members of the academic and industrial community

Geometrical modelling of plain weft knitted fabrics

62-71The accuracy of the prevailing geometrical models of the plain weft knitted fabrics is estimated and a more precise model for the use in computational modelling produced. The new proposed model is based on the assumptions of the ideal elastic yarn and the elastic energy minimization of the yarns composing the relaxed fabrics. Thus, a repeated calculation process is used for the selection of the loop shape corresponding to the minimum loop length. The accuracy of the models is evaluated using the loop length as criterion. Based on the structural data of an extended set of samples, the loop length for every model is calculated. These values are compared to the respective experimentally measured ones. The accuracy of the new proposed model guarantees the success of the mechanical simulation of the knitted fabrics

Piezoelectricity - Organic and Inorganic Materials and Applications

Scientifically defined in 1880 by the Curie brothers, piezoelectricity - from the Greek piezein, meaning to press (squeeze), and ilektron, meaning amber, a material with electrostatic properties - is a phenomenon with many applications. The related piezoelectric materials have been undergoing a long-lasting evolution over the years until today. The field of organic and inorganic piezoelectric materials is continuously expanding in terms of new substances used, new structures, and new applications. The seven chapters of this book present modern aspects and technological advances in the field of piezoelectric materials and applications. To present a balanced view of the field, some chapters focus on new piezoelectric materials and structures, while others examine interesting applications of piezoelectric sensors, energy harvesters, and actuators