As a result of development toward ‘smart’ materials, materials now enable an expanding range of aesthetic expressions and user experiences. These materials are fundamentally temporal in their capacity to assume multiple, discrete states of expression that can be repeatedly and minutely controlled. These materials come to be, or become, only over time and in context—they are becoming materials. Thus, in the development and application of such materials, we must engage more extensively with the experience of materials in practices of design and of use. This paper introduces and discusses the concept of becoming materials—as well as the implications for practice—through a series of examples from our own practice-led research within art, design and architecture. Coming to terms with the implications for material practices of design and of use, we suggest, requires the development of new concepts and methods for doing and studying the design of becoming materials.

The barriers for entering the medical textiles market are rather strong as it is highly technically specialised and dominated by long established players. An approach for entering this market could be to consider the newly evolving 3D-weaving and uniaxial noobing processes as they produce entirely new 3D fabric structures compared with traditional 2D structures. They thus present completely fresh research and business opportunities for developing and marketing innovative 3D fabric based healthcare products.

We are developing a dynamic textile wall hanging as an interface to the atmosphere of a room. Atmospheres are elusive. An atmosphere is the result of an ongoing negotiation between the activities in the room and the expression of the material objects, the lighting, the temperature, and the boundaries of the room [4, 8]. The wall hanging will play an active part in that ongoing negotiation. The activities in the room will influence how the textile wall hanging changes structure, form, color, as well as the pace with which it happens, and the activities in the room may in turn be influenced by the expression of the wall hanging.

Melt Spun Piezoelectric Textile Fibres - an Experimental Study ANJA LUND Department of Materials and Manufacturing Technology Chalmers University of Technology ABSTRACT The manufacturing and characterisation of piezoelectric textile fibres are described in this thesis. A piezoelectric material is one that generates an electric voltage when deformed, a property which exists in a number of materials. The polymer with the strongest known piezoelectric effect today is poly(vinylidene fluoride) (PVDF), however it must be processed under certain conditions to become piezoelectric. This study shows that piezoelectric bicomponent PVDF-based fibres can be produced by melt spinning, which is a common and relatively simple fibre spinning method. The melt spinning process must include cold drawing, as this introduces a polar crystalline structure in the polymer. The fibres must also be electroded, which is done by producing bicomponent fibres with a core-and-sheath structure. The core is electrically conductive and constitutes an inner electrode consisting of a carbon black/polymer compound, whereas the sheath is PVDF and constitutes the piezoelectric component. Being sensitive to both deformation and temperature changes, these fibres are anticipated to be useful in a number of sensor applications. The flexibility and small size of the fibres makes it possible to include them as miniature-sensors in structures or garment without affecting the shape or comfort.

Nanoclay and carbon nanotubes (CNT) have been in focus recently as means of enhancing beta phase crystals formation in poly(vinylidene fluoride)(PVDF). Dominantly, the so-far work has been carried out on films/ thin sheets filled with nanoclay. It has been found, mainly from combined XRD and DSC data, that nanoclay influences the PVDF structure, and particularly the beta phase crystals formation is enhanced. Results published by various groups are in fairly good agreement. There are no results for nanoclay filled melt-spun PVDF fibres. The influence of CNT on PVDF structure has been less studied. XRD data indicating an enhancing role of multi-wall carbon nanotubes (MWNT) on beta phase crystals formation in solution compounded PVDF films are available. Published results for MWNT/PVDF films are not in good agreement. The only study into single-wall carbon nanotube (SWNT)/PVDF has been made on electrospun nanofibres. We explore above findings towards melt-spun nanofilled PVDF fibres. We present new results obtained by us for melt-spun PVDF fibres containing non-functionalized and amino-functionalized double-wall carbon nanotubes (DWNT). The key finding is that amino-DWNT can influence the beta to alpha polymorphic balance.

For the use of poly(vinylidene fluoride) (PVDF) as a piezoelectric material, the processing must include formation of polar β-phase crystallites, as well as the application of electrically conducting charge collectors, i.e. electrodes. In the present paper, results from melt spinning of PVDF yarns and a novel bicomponent PVDF-yarn with a conductive carbon black/polypropylene (CB/PP) core, are presented. Melt spinning has been done under conditions typical for industrial large-scale fiber production. The effects of varying spinning velocities, draw rates and draw temperatures on the resulting crystalline structure are discussed. The results show that for maximum α-to-β phase transformation, cold drawing should take place at a temperature between 70-90°C and draw ratio as well as draw rate should be as high as possible. It was observed that the cold drawing necessary to form β-phase crystallinity, simultaneously leads to a decrease in the core conductivity of the bicomponent yarns. In the present work, melt spinning of bicomponent fibers with high β-phase PVDF in the sheath and a CB/PP core was successfully realized. The core material remained electrically conductive, this paving the way to using a CB-polymer compound as inner electrode in melt spinning of piezoelectric bicomponent fibers.

The application of textile electrodes has been widely studied for biopotential recordings, especially for monitoring cardiac activity. Commercially available applications, such as the Adistar T-shirt and the Numetrex Cardioshirt, have shown good performance for heart rate monitoring and are available worldwide. Textile technology can also be used for electrical bioimpedance (EBI) spectroscopy measurements in home and personalized health monitoring applications, however solid basic research about the measurement performance of the electrodes must be performed prior to the development of any textile-enabled EBI application. This research work studies the performance of EBI spectroscopy measurements when performed with textile electrodes. An analysis using an electrical circuit equivalent model and experimental data obtained with the Impedimed spectrometer SFB7 was carried out. The experimental study focused on EBI spectroscopy measurements obtained with different types of textile electrodes and in different measurement scenarios. The equivalent model analysis focused on the influence of the electrode polarization impedance Zep on the EBI spectroscopy measurements in the frequency range of 3 kHz to 500 kHz. The analysis of the obtained complex EBI spectra shows that the measurements obtained with textile electrodes produce constant and reliable EBI spectra. The results also indicate the importance of the skin-electrode interface in EBI spectroscopy measurement. Textile technology, if successfully integrated, may enable the performance of EBI spectroscopy measurements in new scenarios, which would allow the generation of novel, wearable, or textile-enabled applications for home and personal health monitoring

Electrodes have been widely studied for biopotentials recordings, specially for monitoring the cardiac activity. Commercially available applications, such as Adistar T-shirt and Textronics Cardioshirt, have proved a good performance for heart rate monitoring and are available worldwide. Textile technology can also be used for Electrical Bioimpedance Spectroscopy measurements enabling home and personalized health monitoring applications however solid ground research about the measurement performance of the electrodes must be done prior to the development of any textile-enabled EBI application. In this work a comparison of the measurement performance of two different types of dry-textile electrodes and manufacturers has been performed against standardized RedDot 3M Ag/AgCl electrolytic electrodes. 4-Electrode, whole body, Ankle-to-Wrist EBI measurements have been taken with the Impedimed spectrometer SFB7 from healthy subjects in the frequency range of 3kHz to 500kHz. Measurements have been taken with dry electrodes at different times to study the influence of the interaction skin-electrode interface on the EBI measurements. The analysis of the obtained complex EBI spectra shows that the measurements performed with textile electrodes produce constant and reliable EBI spectra. Certain deviation can be observed at higher frequencies and the measurements obtained with Textronics and Ag/AgCl electrodes present a better resemblance. Textile technology, if successfully integrated it, may enable the performance of EBI measurements in new scenarios allowing the rising of novel wearable monitoring applications for home and personal care as well as car safety

Electrical Bioimpedance (EBI) is one of the non-invasive monitoring technologies that could benefit from the emerging textile based measurement systems. If reliable and reproducible EBI measurements could be done with textile electrodes, that would facilitate the utilization of EBI-based personalized healthcare monitoring applications. In this work the performance of a custom-made dry-textile electrode prototype is tested. Four-electrodes ankle-to-wrist EBI measurements have been taken on healthy subjects with the Impedimed spectrometer SFB7 in the frequency range 5 kHz to 1 MHz. The EBI spectroscopy measurements taken with dry electrodes were analyzed via the Cole and Body Composition Analysis (BCA) parameters, which were compared with EBI measurements obtained with standard electrolytic electrodes. The analysis of the obtained results indicate that even when dry textile electrodes may be used for EBI spectroscopy measurements, the measurements present remarkable differences that influence in the Cole parameter estimation process and in the final production of the BCA parameters. These initial results indicate that more research work must be done to in order to obtain a textile-based electrode that ensures reliable and reproducible EBI spectroscopy measurements.

Accelerated carbonation of recycled concrete aggregates (RCA) could be an efficient way to reduce the carbon footprint. High CO2-concentration under optimal relative humidity could accelerate the CO2 binding capacity of the hydrated cement paste in the RCA. The latter is the topic of this paper. The study looks into the forced carbonation of crushed cement pastes as a basis to understand the CO2 uptake in relation to various binders containing supplementary cementitious materials (SCM) such as fly ash (FA) and ground granulated blast furnace slag (GGBS). Samples include three cement pastes: ordinary Portland cement, substitution rate of 30 % FA and 50 % GGBS respectively at a water/binder ratio of 0.45. All binders were graded to 0/2, 2/4 and 4/8 mm fraction sizes and preconditioned before exposed to CO2 concentration of 10 % under controlled temperature at 20 °C and 65 % RH. All tested binders presented a high CO2 uptake within the first hours of exposure with clear differences concerning the fraction sizes and the composition. The phase content before and after carbonation was observed by X-ray diffraction and the portlandite and calcite were quantified by thermogravimetric analyses and their derivative curves for fraction size 4/8 mm.

In this study bio-nanocomposites were manufactured, using a thermoset resin based on lactic acid and nanoclay (montmorillonite) as a matrix for flax fibers. The obtained composites were characterized by dynamic-mechanical thermal analysis (DMTA) and flexural testing. The aim of this study was to evaluate the mechanical properties of bio-nanocomposites without any surface treatment of the nanoclay and to use the resin/clay blend as a matrix for natural fiber composite. Results showed the nanoclay improved the mechanical properties.

Bio-nanocomposites are a new class of particle-based composites that have attracted much attention due to their environmental and economic advantages these years [1, 2]. In this study a biobased thermoset resin based on lactic acid was used and reinforced with montmorillonite (MMT). This resin consists of star-shaped oligomers of lactic acid, end-capped with methacrylate groups [3]. Thus, the resin can be cross-linked by a free radical polymerization. MMT consists of 1 nm thick aluminosilicate layers. Due to the high surface area, MMT has been evaluated as a reinforcement for several commercial polymers. While most commercial resins are non-polar, MMT is intrinsically polar. Therefore, MMT is usually surface treated in order to make it less polar. However, the resin used in this study is relatively polar and the purpose of this study was to evaluate if untreated MMT could be used to reinforce this resin. The curing was studied with isothermal differential scanning calorimetry (DSC) and the obtained composite were characterized by dynamic-mechanical thermal analysis (DMTA). Also transmission electronic spectroscopy (TEM) was used to characterize the structure. The result showed some improvements in mechanical properties. The DMTA results showed that the storage modulus and also loss modulus of the nanocomposite improved with respect to neat resin. Intercalated structures could be seen from the TEM micrographs.

Articular cartilage possesses unique structure and composition giving rise to unusual mechanical behavior. Typically, it is a structurally graded material that displays variation in mechanical properties along the depth. In this communication, the geometrical probability approach has been used for predicting the in-plane Poisson’s ratio in the surface and middle zones of articular cartilage. The presented model has formulated a relationship between the Poisson’s ratio and collagen fibril alignment. A comparison has been made between the theoretical and experimental findings of Poisson’s ratio in the surface and middle zones of human patella cartilage, as obtained from the literature.

Introduction: After several years of progresses in textile technology and wearable measurement instrumentation, applications of wearable textile-electronics systems are arising providing a stable background for commercial applications. So far, the available commercial solutions are centered on fitness applications and mostly based in the acquisition of heart rate through Textile Electrodes (Textrodes) based on metallic threads or on conductive rubber compounds. Methods and Materials: In this work a novel material approach is presented to produce Textrodes for acquisition of Electrocardiographic (ECG) signals using a conductive polypropylene (PP1386 from Premix, Finland) polymer material. The polymer was film extruded into thin films, and used as such in the Textrode. Conductive Polymer Films (CPF) have been used to produce Textrodes, and its measurement performance has been compared with the ECG signals obtained with commercial Textrode fabrics and conventional Ag/AgCl electrodes. In order to set up the same measurement conditions, a chest strap tailored to host the testing electrodes has been used. Results: The close resemblance of the ECG acquired with the textile fabric electrodes, the Ag/AgCl electrodes and the PP1386 CPF electrodes suggest that the Polymer Electrodes PP1386 are a feasible alternative to the current textile fabrics that use silver thread as conductive material and also to conductive rubber material. Discussion & Conclusion: The availability of the Conductive Polymer Electrode PP1386 in a film form allows the manufacturing of electrodes by conventional textile processes, like lamination or sewing, therefore facilitating the transition from lab prototyping to industrial manufacturing. Replacing the traditional silver thread as conductive element in the fabrication of Textrodes will definitely reduce the material cost per Textrode. Biocompatibility issues and manufacturability issues must be addressed but the exhibited functional performance is showing encouraging results.

Embedding computers into our environment is perhaps not only a job for computer scientist and engineers. We propose to understand the computer as a material for design as means to invite artists, architect, and designers to participate in envisioning how and where the computational power can be used. We will invite the conference attendees to (once again) think about how to bridge the so-called gap between computational and material properties but this time using a material rather than the traditional information centric perspective. The invitation is extended through hands-on experiences with our two samples of computational composites.

Designing Dynamic Textile Patterns Progress in chemistry, fibres and polymers technology provides textile designers with new expressive materials, making it possible to design dynamic textile patterns, where several different expressions are inherent in the same textile, textiles that, for example, could alternate between a striped and checkered pattern. Textiles are traditionally designed and produced to keep a given, static expression during their life cycle; a striped pattern is supposed to keep its stripes. In the same way textile designers are trained to design for static expressions, where patterns and decorations are meant to last in a specific manner. However, things are changing. The textile designer now deals also with a new raw material, a dynamic textile, ready to be further designed, developed and/or programmed, depending on functional context. This transformation in practice is not an easy one for the designers. Designers need to learn how to design with these new materials and their specific qualities, to be able to develop the full expressional potential inherent in “smart textiles design”. The aim of this thesis is to display, and discuss, a methodology for designing dynamic textile patterns. So far, something that mainly has been seen in different experimental and conceptual prototypes, in artistic expressions and for commercial efforts etc. In terms of basic experimental research this thesis explores the turn in textile design practice through a series of design experiments with focus on contributing to identifying and characterizing new design variables, new design methods and new design techniques as a foundation for dynamic textile patterns.

The work presented here addresses the outer electroding of a fully textile piezoelectric strain sensor, consisting of bi-component fibre yarns of β-crystalline poly(vinylidene fluoride) (PVDF) sheath and conductive high density polyethylene (HDPE)/carbon black (CB) core as insertions in a woven textile, with conductive poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) coatings developed for textile applications. Two coatings, one with a polyurethane binder and one without, were compared for the application and evaluated as electrode material in piezoelectric testing, as well as tested for surface resistivity, tear strength, abrasion resistance and shear flexing. Both coatings served their function as the outer electrodes in the system and no difference in this regard was detected between them. Omission of the binder resulted in a surface resistivity one order of magnitude less, of 12.3 Ω/square, but the surface resistivity of these samples increased more upon abrasion than the samples coated with binder. The tear strength of the textile coated with binder decreased with one third compared to the uncoated substrate, whereas the tear strength of the coated textile without binder increased with the same amount. Surface resistivity measurements and scanning electron microscopy (SEM) images of the samples subjected to shear flexing showed that the coatings without the binder did not withstand this treatment, and that the samples with the binder managed this to a greater extent. In summary, both of the PEDOT:PSS coatings could be used as outer electrodes of the piezoelectric fibres, but inclusion of binder was found necessary for the durability of the coating.

Polymers are typically produced from crude oil which is a non-renewable resource. With the fast depletion of the petroleum resources, the development of materials based on renewable resources is becoming important. Polymers prepared from renewable resources are under development, but has mainly focused on thermoplastic polymers such as polylactic acid. For some applications, such as composites and coatings, thermoset polymers are often preferred. Consequently, it is important to develop thermoset resins from renewable resources as well. Plant oils, such as soybean oil and linseed oil, have been utilized by mankind for a long time. Soybean oil is produced in large quantities and soybean oil is an excellent starting material for the synthesis of thermoset resins. A possible strategy to prepare thermoset resins from plant oils is to introduce pendant methacrylate groups in the structure. Thus, the resins can be cured by a free radical polymerization. Such a resin is very susceptible to photopolymerization when exposed to ultraviolet (UV) radiation, which is a common technique to cure coatings. In the present study, three different thermoset resins were studied. Two of the resins were based on soybean oil while the third resin was based on lactic acid. The latter resin was prepared by a direct condensation of lactic acid and pentaerythritol and was finally end-capped with methacrylate groups. Several authors have studied the addition of nano-reinforcements to thermoset resins. One of the most promising nano-reinforcements is layered silicate which has shown to improve several properties. Layered silicate has been used to reinforce conventional resins with good results. The addition of layered silicates to the biobased resins can be used to improve the properties and to broaden the applications. The resins used in this study were therefore reinforced with layered silicate and UV-cured. The cured resins were characterized by Soxhlet extraction, photo-FTIR, DMTA and tensile tests which will be presented during the presentation.

A scrap blade from a wind turbine was microwave pyrolysed. The recovered glass fibres were characterised by SEM and TGA. The possibility to use the fibres to prepare new composites were evaluated. Laminates were prepared where fibres mats with virgin and recovered glass fibres were altered. Mechanical testing showed that it is possible to prepapare composite with up to 35 wt.-% recovered fibre without losing too much of the mechanical properties.

Abstract Thermoset composites were produced from flax fibers and a novel lactic acid (LA)-based thermoset resin. This resin is based on methacrylated, star-shaped oligomers of LA. The main purpose of this work was to evaluate whether this resin can be used to produce structural composites from flax fibers. Composites were prepared by spray impregnation followed by compression molding at elevated temperature. The tests showed that composites can be produced with as much as 70 wt% fiber. The composites were evaluated by tensile testing, flexural testing, charpy impact test, dynamic mechanical thermal analysis (DMTA), and low-vacuum scanning electron microscopy. The ageing properties in high humid conditions were evaluated, the Young's modulus ranged from 3 GPa to 9 GPa in the best case. This work shows that structural composites can be produced from renewable material. It is clear from the results that these composites have properties that make them suitable for furniture, panels, or automotive parts.