Symposium L
Smart and Interactive Textiles

Session L-1 - Adaptive/Active Textiles

L-1:IL01  Interfacial Force Mapping by Artificial Smart Skins
XIAOMING TAO^1,2, ZHIFENG ZHANG¹, FEI WANG¹, QIAO LI¹, ¹Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong, China; ²Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China

With many upcoming aging societies, the need for surgery robots in hospitals, and the demand for automated assembly lines, touch-sensitive artificial skins have become imperative for interfacial force mapping in robotics, biomedicine and health-care, etc. These artificial smart skins entail soft pressure and shear force sensors and stretchable interconnects on a flexible and stretchable substrate. During the past decades, substantial effort has been made to create smart skins for interfacial force mapping. On one hand, such endeavours produced diverse tactile sensors with distinctive traits analogous to or even outperforming that of the human skin. Nevertheless, it remains challenging to produce tactile sensors with sufficiently high sensitivity, stretchability, softness and three-axial force mapping capability, especially in the low pressure regime (<10 kPa) and shear force. On the other hand, robust and stretchable circuit boards for sensor connections have long been a critical issue despite the great effort made. Therefore, we present two types of soft pressure/force sensors and one type of fabric circuit board for force mapping and sensor connection in artificial smart skins respectively. First, soft pressure/shear force sensor is based on elastomer composite integrated with polymer fibre Bragg gratings (PFBGs). A systematic study was therefore carried out on the PFBG formation in polymethyl methacrylate (PMMA) based fibres doped with trans-4-stilbenemethanol (TS). TS was chosen for the photoisomerisation, non-degradation, and thermally-stable cis state at room temperature. Firstly, step-index single-mode polymer optical fibres (POFs) were fabricated by perform-drawing method, and then inscribed using phase masked UV exposure at an optimized period of 5 min. For the first time, it was found that Bragg peak of such inscribed PFBGs demonstrated a relaxation process, which was induced by photoisomerization, because trans- and cis-isomers of 4-stilbenemethanol are different in geometry. Despite a synergetic sensitivity in temperature and humidity, the PFBGs at 1310 nm showed a high sensitivity of 1.2 pm·με-1 to longitudinal strains below 1%. After the study on formation mechanisms of PFBGs, a soft sensor was developed by imbedding two PFBGs into a silicone cube. The sensor was able to detect both normal and shear force simultaneously because the two PFBGs were not parallel: one was horizontal, and the other tilted. Two gaskets placed at two ends of each fibre, a release agent applied onto fibres ensures minimum adhesion between the optic fibers and the silicone. As revealed in a finite element analysis, strain distribution along fibre axis was non-uniform if the fibre was bonded into silicone matrix. Such soft PFBG sensors demonstrate excellent normal and shear force sensitivities at 0.82 and 1.33 nm·kPa-1 respectively. Besides, the sensor has similar Young’s modulus to that of the human skin. The second type is an all-elastomer pressure sensor array for 3-axial contact force measurement, the structure of which was inspired by the skin of a toad. It was fabricated by injecting polyethylene glycol (PEG) 400 between two PDMS layers with stencil printed carbon/silicone strain gauges, and silver/silicone conductive interconnects. Being composed exclusively of elastomeric materials and liquid, the sensor array exhibited a stretchability and elastic modulus approaching those of a human skin, which marks substantial progress of tactile sensors in this regard. The sensor was tested on an electromechanically coupled setup with a pulley to redirect loading. A sensitivity of 0.097 N-1 to normal forces below 1.62 N and an excellent sensitivity of 0.337 N-1 to shear forces below 1.3 N (with a normal force at 0.4 N) have been achieved, exceeding the best reported flexible 3D force sensors, especially for small shear forces below 0.5 N. Such soft sensor arrays can be used in gait analysis, slippage detection and dexterous manipulation of robots, etc, where friction measurement is of utmost importance. The last is fabric circuit boards (FCBs). As a new type of circuit boards, the FCBs are three-dimensionally deformable, highly stretchable, durable, and washable. They are fabricated by using computerized knitting technologies at ambient conditions. The FCBs exhibit outstanding electrical stability with less than 1% relative resistance change at up to 300% strain in unidirectional tensile test, and 150% membrane strain in three-dimensional ball punch test, an extraordinary fatigue life of over 1 000 000 loading cycles at 20% strain, and a 30-time washing capability. Theoretical analysis and numerical simulation illustrate that these excellent electromechanical properties are mostly attributed to the structural conversion of knitted fabrics, which effectively mitigates the strain in metal fibres. To the best of our knowledge, the new FCBs has far exceeded previously reported metal-coated elastomeric films or other organic materials in both mechanical and electrical properties, including changes in electrical resistance, stretchability, fatigue life, washing capability, and permeability. These features make the FCBs particularly suitable for next-to-skin electronic devices. Moreover, as a demonstration of potential applications, the FCBs have been integrated in smart protective apparel for in-situ strain measurement during ballistic impact. The FCBs provided effective electromechanical connection of strain sensor elements during ballistic impact, and reliable electrical signals were acquired from the sensor arrays. The above three technologies of fibre-structured electronics/photonics are suitable candidates for artificial skin use. They will lead to substantial advancement for interfacial force mapping by artificial smart skins.
The work reported here has been partially supported by Research Grants Council and National Science Foundation of China (grants no. N-polyu503/12, PolyU5251/13E). Theme (Abstract Category): Smart and Interactive Textiles Corresponding author: Xiaoming Tao (xiao-ming.tao@polyu.edu.hk)


L-1:IL03  Adaptive Textile Materials
S. MINKO, Nanostructured Materials Lab, Department of Textiles, Merchandising, and Interiors, University of Georgia, Athens, GA, USA

Recent accomplishments in the area of stimuli-responsive surfaces and interfaces, sensors and microactuators, porous materials, flexible electronics, nanostructured thin films and nanofibers created a diverse base for developments of a new generation of smart and adaptive consumer materials including fibers, yarns and fabrics. Innumerable yet examples of commercialized smart/adaptive textiles is just a start of the phase of new developments for making fabrics that actively manage heat and humidity transport, electrical conductivity, wetting behavior, energy storage and harvesting, biological functions, antimicrobial properties, and many others properties that could be potentially highly demanded but not yet well elaborated and understood. This presentations is a brief overview of the research of our laboratory in the area of adaptive textiles that includes nanostructured textile finishes, functional nanofibers and particulates, nanocellulose and thin films that are used for the development of advanced functional textile materials. Specific attention is to discuss applications of nanostructures and their assemblies to develop adaptive properties of textiles.


L-1:IL04  Shape-memory Nanocomposite Elastomers filled with Carbon Nanomaterials
G.C. LAMA^1,2, G. GENTILE¹, P. CERRUTI¹, V. AMBROGI^1,2, C. CARFAGNA¹, ¹Institute for Polymers, Composites and Biomaterials of Italian National Research Council (IPCB-CNR), Pozzuoli, Italy; ²Department of Chemical Engineering, Materials and Industrial Production, University of Napoli, Napoli, Italy

Shape memory elastomers are a class of polymers that, after a deformation to fix a temporary form, are able to recover their original shape. The recovery effect can be activated by different external stimuli, such as the application of a voltage, by the change of the temperature or the change of the pH of a solution. The main objective of this work has been the preparation and characterization of nanocomposites based on a rigid epoxy monomer cured in presence of an aliphatic dicarboxylic acids and filled with modified carbon nanomaterials such as multiwalled carbon nanotubes (CNT) or graphene. The study has been focused on the optimization of the preparation methodology and on the evaluation of the effect of different contents of carbon nanofillers on the properties of the obtained materials. In particular, dispersion test, infrared spectroscopy, thermogravimetric analysis and bright field trasmission electron microscopy were carried out to characterize the modified fillers. Moreover, the nanocomposite materials were characterized by morphological analysis, differential scanning calorimetry and thermomechanical analysis in order to clarify the effect of the nanofillers on the shape memory properties of the material.


L-1:L05  Active Textile Materials via Polymer Grafting
I. LUZINOV, Department of Materials Science and Engineering, Clemson University, Clemson, SC, USA

The surface characteristics of textiles may often be decisive to their suitability for applications, since friction, abrasion, wetting, adhesion, adsorption, and penetration phenomena are involved. In order to obtain textiles with the desired surface performance, their boundary is often modified before use. To this end, the present communication focuses on synthesis and performance of the nanoscale, chemically grafted polymer layers on fibrous materials. The synthesis has been conducted employing reasonably universal macromolecular anchoring layer approach. Specifically, reactive, hydrophobic, oleophobic, hydrophilic, gradient and switchable grafted polymer layers were permanently anchored onto fibers modified with poly(glycidyl methacrylate) anchoring layer. As a result, active textile materials were obtained and their performance was tested.


L-1:L07  Temperature Responsive 3D Nitinol Textile with Adaptive Cross-section
M. VYSANSKA, K. JANOUCHOVA, O. LOUDA, Technical University of Liberec, Faculty of Textile Engineering, Liberec, Czech Republic; L. HELLER, P. SITTNER, Institute of Physics AS CR, vi v. i., Prague, Czech Republic

Shape memory alloys such as equiatomic NiTi called Nitinol feature attractive temperature sensing and responsive functional properties. In addition, thin Nitinol filaments (~100 μm) show outstanding stability of functional properties and the ability to recover large strains up to 10% making them moderately deformation-compatible with common textile materials. Therefore, thin Nitinol filaments are being considered for applications in functional textiles. We will present a proof-of-concept of a lightweight hollow 3D NiTi textile able to increase the effective cross-section thickness when the temperature of surroundings reaches a defined temperature. First, we will describe the design of the NiTi textile relying on a smart weft knitting pattern consisting of two layers that are periodically interlaced. Then the textile manufacture involving heat treatment under constraints called shape setting will be explained. The temperature responsive function of the NiTi textile will be illustrated by results of dedicated thermomechanical experiments. Finally, we will discuss the possibility of using this NiTi textile as a core of thermally protective garments that increase the heat insulation properties and warn the user whenever the surrounding temperature reaches a critical value.


L-1:L09  Electromechanically Active Textiles for Soft Robotics
A. MAZIZ¹, A. KHALDI¹, N.-K. PERSSON², E.W.H. JAGER¹, ¹Biosensors and Bioelectronics Centre, Dept. of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden; ²Smart Textiles, University of Borås, Borås, Sweden

There has been an increasing demand to make novel human-friendly robots capable of working alongside humans. Such soft robots need to be compliant, lightweight and equipped with silent and soft actuators. Conducting polymers (CPs) are “smart” materials that deform in response to electrical simulation and are often addressed as artificial muscles due to their functional similarity with natural muscles. They offer unique possibilities and are perfect candidates for such actuators since they are lightweight, silent, and driven at low voltages. We have developed novel generation of soft actuators that combine one of humankind oldest technology with one of the latest, that is to combine the textile techniques of weaving and knitting with CPs. The use of innovative textiles technology provide a more conformal and natural motion to soft robotics, prosthetics and exoskeletons. We have developed new CP based fibres and novel architectures employing parallel assembly of the CP fibres using advanced textile technology resulting in electroactive textile actuators. These will provide enhanced actuation strain, speed and stress, similar to natural muscles.. We will present the fabrication and characterisation of these CP based textiles as well as their performance as linear actuators.


L-1:L10  Textile Materials with SMA Elements for Active Protection against Heat and Flame
G. BARTKOWIAK, A. DABROWSKA, Central Institute for Labour Protection, National Research Institute, Warsaw, Poland

The newest research directions related to designing of the protective clothing concern implementation of smart materials, such as shape memory alloys (SMA), that allow for its functionalisation which could not be achieved with traditional materials. As a result of the research project, a thermo-mechanical treatment programme of a nickel-titanium alloy has been elaborated. This programme allows for achieving active elements in a form of conical springs that are characterized by two-way shape memory effect and predestined for implementation into the protective clothing. Textile materials with SMA elements intended for the clothing protecting against flame, radiant heat and molten splashes have been developed and manufactured. Laboratory tests aimed at evaluation of the obtained shape change effect were performed according to the specially modified testing methodology. Test results indicated that SMA elements caused an improvement of the protective properties of textile materials due to their increased thickness and creation of an additional air layer. On the basis of the achieved results, it can be also stated that protection performance of clothing according to the EN ISO 11612:2008 can be increased from 1 to 2 levels by means of textile materials with SMA elements.


L-1:L11  Dispenser printed Actively Controlled Thermochromic Colour Changing Device on Fabric for Smart Fabric Applications
YANG WEI, Z. AHMED, R. TORAH, J. TUDOR, University of Southampton, Hampshire, UK

This paper reports a dispenser printed actively controlled thermochromic colour change device on PVC coated polyester fabric for smart fabric applications in the creative industries. The chosen thermochromic material changes transparency in response to temperature change, which in this device is provided by a printed heater. Dispenser printing is a direct-write additive manufacturing process, using pressure to dispense an electrically functional ink onto a fabric substrate moved by XYZ stages and controlled by PC. Dispenser printing provides enhanced design freedom and can print multi-layer and multi-material devices without extra tooling. The thermochromic device consists of three printed layers: •Layer 1: An inkjet printed artwork, revealed when the thermochromic layer becomes transparent. •Layer 2: A set of two parallel conductive tracks, acting as a resistive heater controlling the transparency of the thermochromic layer. •Layer 3: The thermochromic layer of which the colour changes from opaque black to transparent once the fabric temperature exceeds 31°C, the transition temperature of the thermochromic material. A faster transition occurs for higher heater currents but with a slower return to opaque with no current. We report device design, fabrication and characterisati


L-1:IL12  Advanced Microgel-functionalised Polyester Textiles Adaptive to Ambient Conditions
P. GLAMPEDAKI, Pharmathen, R&D Dpt., Pallini, Attiki, Greece

A new approach towards textiles adaptive to their environment was explored. To this end, polyelectrolyte microgel technology was combined with conventional functionalisation methods to activate the surface of polyester textiles. Biopolymer microgels consisting of soft pH/thermo-responsive microparticles complexed with the oppositely charged natural polysaccharide chitosan were devised. Microgel incorporation into polyester surface layers was achieved either through UV irradiation or through low temperature treatment. The adaptability of the functionalised textiles to ambient conditions of pH, temperature and relative humidity was expressed by changes in their physicochemical and water management properties. These changes were found to occur within a physiological pH/temperature range of the human body (pH 4-8, 20-40°C), giving scope for applications in the fields of biomedicine and protective clothing. Indicatively, such changes involved a shift in polyester surface charge from positive to negative values at a pH range 5.0-6.6, following the trend of the incorporated microgels. Below 36°C, functionalised textiles exhibited improved water wettability, whilst above 36°C they had lower moisture regain and higher water vapour transmission rates than the non-functionalised textiles.


L-1:IL13  Advances in Photovoltaic Fabrics
YONG K. KIM, University of Massachusetts, Dartmouth, MA, USA

In the last decade, power conversion efficiency (PCE) of organic photovoltaics (OPV) has risen from 2.5 to 11%. This implies that the current photo voltaic (PV) cells based on inorganic semiconductors can be replaced by polymeric OPVs, which are inexpensive to fabricate and can be solution-processed in a roll-to-roll fashion to produce PV films and PV wires with high throughput. In this invited lecture, recent advances in OPV material development, PV wires, and PV fabrics are discussed.

 
Session L-2 -  E-textiles

L-2:IL01  Printed Electroluminescent Fabrics
P. CALVERT, New Mexico Tech, Socorro, NM, USA; Bin Hu, Dartmouth College, Hanover, NH, USA

Electroluminescence offers a versatile and simple route to printed light sources. A layer of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was inkjet printed onto polyethylene terephthalate (PET) mesh fabrics. The conductivity–transparency relationship is determined for textile-based conductors with different thicknesses of the printed PEDOT:PSS film. Alternating current powder electroluminescent devices were made by extrusion printing a layer of phosphor onto aluminum foil and then covering this with a fabric electrode. These devices are compared with indium tin oxide (ITO) glass electrodes on a similar device. Textiles coated with conducting polymers are a potential alternative to coated polymer films for flexible, transparent conductors. The strain response of these electrodes was improved by incorporating carbon nanotubes into the conductor. These bridge cracks that form on stretching.


L-2:IL02  Vibration Energy to Electricity Conversion of Electrospun Nanofibers
JIAN FANG, XUNGAI WANG, TONG LIN, Deakin University, Institute for Frontier Materials, Geelong, Australia

Among various renewable energy resources currently under investigation, small mechanical energies and vibrations are widely available in our daily life. It’s of great importance to develop effective technology to convert these mechanical energies into electricity. Recent studies have revealed that ferroelectric polymeric nanofiber prepared by electrospinning have great potential in mechanical-to-electric energy conversion for powering microelectronics. In this talk, unique energy conversion behaviour of needle-based and needleless electrospun nanofibers, systematic understanding of electrospinning parameters on fibrous structure and electric output stability, as well as their application demonstration in self-powered microelectronics are presented.


L-2:IL04  Resistance-invariant Superstretchable Conductor for DC and AC Signal Transmission
YOURACK LEE, LE VIET THONG, MIN-KYU JOO, YOUNG HEE LEE, DONGSEOK SUH, Department of Energy Science, and IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea

Stretchable conductors have been investigated for a long time due to their potential use in applications such as flexible electronic devices and implantable medical devices. One of the critical disadvantages in previous reports is the extremely large variance in electrical resistance when stretched (especially above 100% strain) because of percolation based charge conduction and the change of conductor dimensions. Here, we showcase a simple, low-cost elastomeric conductor stretchable even up to 600% without substantial increase in resistance in the stretch direction. Inherent elasticity of a polymeric rubber and the high conductivity of flexible, highly-oriented carbon nanotube (CNT) arrays were combined synergistically without major degradation in either property. It was ascribed to the formation of conductive wavy folds on the surface of elastomer for resistance-invariant stretchable conductor to keep the length of conductive path unchanged. Basically the maximum working strain range (currently demonstrated up to 600%) is limited by the property of elastomer, not that of CNT layer. Not only DC but also AC signal up to 10 MHz could be transmitted through this stretchable conductor. Exemplary applications such as stretchable audio and video signal lines will be presented.


L-2:IL07  Electronic Textiles Fabricated using Atomic Layer Deposition
HAN-BO-RAM LEE, Department of Materials Science and Engineering, Incheon National University, Incheon, Korea  

Atomic layer deposition (ALD) is a thin film deposition method employing self-saturated surface reactions in vaccum environments. Since ALD has several superior properties for nanoscale device fabrications, such as excellent conformality, large area uniformity, and process compatibility, over the conventional thin film deposition methods, it has been widely applied for various high technology applications from semiconductor to display devices. ALD can be an effect route to form materials with precise controllability in other applications. In this work, we extended ALD researches to electronic textile applications. We developed a Pt ALD process capable of low temperature deposition down to 80 °C using a new Pt precursor and O₂ counter reactant. Pt was deposited on organic textile substrates, such as cotton and Nylon. The ALD-Pt-coated textiles showed high electrical conductivity and high mechanical durability even after mechanical wrinkling test. Fabrications of pressure sensor arrays using ALD-Pt-coated textile were demonstrated.


L-2:IL08  Plastic Electronics as a Versatile Technology based on Organic Semiconductors: Perspectives for Smart Textiles
D. VANDERZANDE, imo-imomec, Hasselt University, Hasselt, Belgium

Organic semiconductors have found their way toward applications in electronic devices, e.g. LED's, transistors, solar cells and (bio-) sensors. Their most attractive feature is related to the use of flexible substrates and the potential of printing technology as processing technology. More and more the potential use comes in sight that allows combining these plastic electronics with textiles in general, creating a platform for smart textile applications. In this contribution the latest results obtained in our institute concerning devices and their performances will be discussed with a main focus on solar cells. Also still open questions and hurtles to implementation will be reviewed.


L-2:L09  Hybrid Large-area Thin-film / CMOS System Technology for Wearable Electronics
S. WAGNER, W. RIEUTORT-LOUIS, J. SANZ-ROBINSON, T. MOY, L. HUANG, Y. HU, Y. AFSAR, J.C. STURM, N. VERMA, Princeton University, Princeton, NJ, USA  

Next-generation wearables will rely on active fabrics made by weaving conductor, insulator and semiconductor fibers sparsely into textile yarn. Fabrics woven from such yarns will enable electronic functions that seamlessly integrate into everyday, comfortable, lightweight clothing. Functionality and comfort of these wearables could benefit from the architecture, signal processing, and fabrication technology that we have been devising for flexible large-area electronics. Our hybrid systems combine CMOS with thin-film circuits and subsystems. While CMOS is primarily responsible for fast and energy-efficient computation, flexible large-area electronics provides a wide array of sensors and output devices to enable interfacing with the macroscopic world. Here we focus on two aspects of our physical implementations that are of particular interest to wearables. One is the use of in-plane transmission over wires; this saves energy per transmitted bit, over wireless communication, which is important for energy-autonomous wearables. The other aspect is up-and-down connections via capacitors or inductors, which enable sliding contacts; these can provide fabric with a comfortable “hand.” We will discuss our hardware implementations and their properties.


Session L-3 -  Functionality, Manufacturing, Application

L-3:IL01  Aulana® and NgaPure®: Nanogold coloured and Antimicrobial Silver Woollen Textiles – A Journey from Discovery to Commercialisation
J.H. JOHNSTON, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand

Aulana® is pure gold and pure wool. Here we form and bind nanogold particles in different colours to the keratin protein in wool fibres in a proprietary technology, commercialised by Noble Bond Ltd, to produce an innovative, boutique colour range of nanogold-wool textiles for high value international luxury apparel, fabric and rug markets. Aulana® captures the exciting opportunity to combine the high quality of New Zealand wool with the prestige and value of gold. It uses the localised surface plasmon resonance properties of nanogold to generate the different colours. Spherical particles of gold 10-20nm in size are pink-purple in colour. By precise control of the particle size and shape, the colour can be changed through shades of pink, red, purple, blue, blue-grey and grey. Nanogold colourants cannot fade and Aulana® products exhibit excellent lightfastness. In a similar way we use the nanotechnology and antimicrobial properties of silver to develop a highly effective and durable antimicrobial technology for woollen textiles for transportation, public seating, medical, flooring applications. This is also being commercialised by Noble Bond Ltd as the NgaPure® technology and brand. An overview of the products and the pathway from discovery to commercialisation will be presented.


L-3:IL02  Reliable Fabric-based Organic Light-emitting Diodes
KYUNG CHEOL CHOI, SEONIL KWON, WOOHYUN KIM, HYUN CHEOL KIM, SEUNGYEOP CHOI, School of Electrical Engineering, KAIST, Republic of Korea

Wearable electronics have emerged as a major area of interest both academically and industrially because wearable electronic devices have the potential to increase the comfort of users. In order to realize wearable electronic devices, it is very important, but difficult, to prevent the loss of the intrinsic flexibility properties of fabrics or fibers used when adding electronic functions to these types of substrates. With regard to wearable displays, organic light-emitting diodes (OLEDs) have a number of superb features, such as extreme thinness, good flexibility, a light weight, and a low driving voltage. Thus, it is possible to introduce these products into wearable displays without affecting the intrinsic flexible properties of the substrates used. On the other hand, OLEDs are vulnerable to performance degradation from oxygen and water. In addition, the rough surfaces of general fabric or fiber substrates detrimentally affect the reliability and stability of very thin OLEDs. Thus, this work proposes the use of planarization layers to preserve the operational stability of OLEDs. The proposed layers improve the reliability of OLEDs without changing of innate flexibility of the fabric and fibers used. OLEDs on fabric and fiber substrates are shown using the proposed layers, with the results demonstrating the potential to create truly comfortable fabric-based wearable displays.


L-3:IL03  Resorbable Fibrous Polymers in Terms of Forensic Engineering of Advanced Polymeric Materials
M. KOWALCZUK, Polish Academy of Sciences, Centre of Polymer and Carbon Materials, Zabrze, Poland; School of Biology, Chemistry and Forensic Science, Faculty of Science and Eng., University of Wolverhampton, UK

Forensic engineering of advanced polymeric materials (FEAPM) deals with the evaluation of the relationships between their structure, properties and behavior before, during and after practical applications [1]. It is of particular importance in the case of resorbable fibrous polymers where FEAPM studies are needed in order to increase efficiency and to define and minimize potential failure of novel fibrous polymer products. Comprehensive report on FEAPM studies of biomaterials derived from aliphatic (co)polyesters will be presented. Special emphasis will be given to the nonwovens derived from tin-free PLGA, and PLGA blends with PHA analogues. The FEAPM prediction studies revealed, that release of lactic and glycolic acids from the non-woven fabrics is dependent on their formation method. Moreover, the continuous release of lactic and glycolic acids from the PLGA biomaterials studied allows their gradual removal via biochemical processes and prevents local acidification of the body [2].
1. J. Rydz, K. Wolna-Stypka, G. Adamus, H. Janeczek, M. Musioł, M. Sobota, A. Marcinkowski, A. Kržan, M. Kowalczuk, Chem. Biochem. Eng. Q., 2015, 29, 247. 2. W. Sikorska, G. Adamus, P. Dobrzynski, M.Libera, P. Rychter, I. Krucinska, A. Komisarczyk, M, Cristea, M. Kowalczuk, Polymer Deg. Stab., 2014, 110, 518.
This work was partly supported by key project: “Biogratex” POIG.01.03.01-00-007/08 and Polish National Centre of Science: decision DEC-2012/07/B/ST5/00627.


L-3:IL06  Design of Instructive Fibre Platforms for Tissue Engineering and Drug Delivery Applications
V. GUARINO, V. CIRILLO, R. ALTOBELLI, L. AMBROSIO, Institute of Polymers, Composites & Biomaterials and Department of Chemical Sciences & Materials Technology, National Research Council of Italy, Naples, Italy

In the biomedical field, it is growing the request of alternative routes to synthesize instructive biomaterials with biologically recognized functionalities to “in vitro” reproduce all the main functionalities exerted “in vivo” by health tissues. Among them, Electrofluidodynamic techniques (EFDTs) are emerging as highly flexible and low-cost processes to manipulate biomaterials by utilizing electrostatic forces, in order to address cell fate in vitro. By a rational selection of polymer solution properties and process conditions, EFDTs allow producing fibres and/or particles at micro and/or sub-micrometric size scale which may be variously assembled by tailored experimental setups, thus generating a plethora of different 3D devices with peculiar topological or biochemical signals Here, we overview the current advances in the use of basic EFDTs – i.e., electrospinning [1], electrospraying [2] and electrodynamic atomization [3] - to develop bio-inspired platforms for tissue engineering, drug delivery and cancer therapy.
[1] Guarino V et al Exp Rev Med Dev. 2015 12,113; [2] Guarino V. et al., Polym Adv Tech 2015 DOI: 10.1002/pat.3588; [3] Guarino et al Patent no.WO2009143947 A1 (2009).
Acknowledgement: MERIT, MIUR-RBNE08HM7T-001 and NEWTON (FIRB-RBAP11BYNP) and REPAIR (PON01-02342)


L-3:IL08  Manufacturing Nanoyarns for Conventional and Technical End Uses
G.K. STYLIOS, Heriot Watt University, Scotland, UK

Here we show a new process of converting nanofibres into orderly oriented bundles of nano sliver. A rotating drum with its surface covered with cardwire (bent electrically charged wire) is rotated, the nanofibres are collected on the surface of the wires and removed by a doffing knife set along the surface width of the card. An example of how an orderly Nylon 6 nano sliver web can be produced and subsequently spun into a nano yarn is explored in this paper. Electrocarding facilitates yarn spinning using existing and not purpose built spinning machinery and thus enabling the design and manufacture of new yarn nano-based products. The ability to mass produce yarns with this technology is particularly important, for making new structures with new performance and aesthetic properties by weaving, knitting and braiding.


L-3:L09  Fabrication of Silver-zinc “Battery Fabric” for Applications in SMART Textiles
A.M. ZAMARAYEVA, I. DECKMAN, CH. CHANG, A.C. ARIAS, Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, CA, USA; M. WANG, D.A. STEINGART, Mechanical and Aerospace Engineering, Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, USA

Flexible energy storage devices are an indispensable part of rapidly advancing wearable SMART garments. Some significant challenges in achieving deformability while maintaining high areal capacity of these devices remain unresolved. Here we introduce new approach to engineer battery system by making electrodes in the form of micron-size threads, which are then interlaced into yarn, which in turn is weaved into the “battery fabrics”. The battery utilizes silver-zinc chemistry, which in addition to being energy dense, is based on aqueous electrolyte and thus, is intrinsically safer than battery chemistries that rely on organic solvents. While in traditional layered electrode design, the flexibility of the electrode is effected by the film thickness, limiting the capacity of the battery, using yarns weaved into fabrics allows to achieve exceptional flexibility without compromising capacity. Weave design will determine areal capacity and mechanical properties of the “battery fabric” and can be chosen based on the particular product requirements. The battery yarns weaved into the plain weave result into the “battery fabric” with high areal capacity of 9 mAh cm-1 when discharged at 0.5 C rate, which is considerably higher than recent demonstrations of flexible batteries.


L-3:L10  New Nanogold Colours for Textiles
E.G. WRIGGLESWORTH, J.H. JOHNSTON, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand

We present a novel green synthesis using a combination of reductants to produce gold nanoparticles with anisotropic particle morphologies that exhibit violet and blue colours due to localised surface plasmon resonance effects. Gold nanoparticles produced by single reductant methods typically exhibit pink, red and purple colours. Extending the colour range usually involves environmentally problematic structure directing agents whereas our synthesis uses naturally occurring materials. Recently Prof. J.H. Johnston and Dr K.A. Lucas have developed and commercialised a proprietary technology to colour wool with gold nanoparticles for international luxury markets. In the synthesis presented here a combination of reductants are used to construct gold nanoparticles from an Au3+ solution, wherein the mechanism of nanoparticle growth differs from when each reducing agent is used alone. Different shapes and sizes of nanoparticles and hence different coloured colloids are produced for application to yarn. The gold colloids and the subsequent coloured gold-wool will be presented. UV-visible spectroscopy, dynamic light scattering and electron microscopy were used to characterise the nanoparticles and the gold-wool composites. The likely mechanism of nanoparticle growth will be discussed.


L-3:L11  The Incorporation of Phase Change Material into Soft Armour Inserts: Achieving a Level of Cooling without Compromising Ballistic Protection
K.C. NG, A.P. HUNG, P. TAN, H. BILLON, M.F. LING, Defence Science and Technology Group, Department of Defence, Melbourne, VIC, Australia

Dismounted combat personnel operating in hot and humid climates can experience serious thermal stress, exacerbated by the lack of breathability of their body armour systems, which usually consist of hard ceramic armour plates and Soft Armour Inserts (SAI). Smart textiles such as increased breathability will have little to no benefit under the body armour system, and active cooling has a number of disadvantages that render them unsuitable in an operational context. Over the past couple of decades, Phase Change Materials (PCM) have found applications in sports and protective clothing for maintaining thermal comfort as the surroundings heat up, or at least delaying the onset of thermal stress, through effective cooling. In laboratory trials involving both thermal manikin and human participants, it was found that the use of vests containing PCM consistently resulted in lower skin (both artificial and real) temperatures compared with those without PCM. Here we explore the practicality of integrating PCM with Kevlar fabrics into the SAI to achieve the dual function of ballistic protection and thermal buffering, in an attempt to find a balance between a beneficial level of effective cooling and the requisite level of ballistic protection.


L-3:L12  Airbrushed Liquid Crystal/Polymer Fibers for Responsive Textiles
J.L. WEST, J. WANG, A. JAKLI, Liquid Crystal Institute, Kent State University, Kent, OH, USA

We report formation of complex responsive fibers consisting of a low molecular weight liquid crystal, LC, core surrounded by a polymer sheath using simple airbrushing or jet spraying techniques. The fibers are formed using a solution of the LC and polymer dissolved in a common solvent. With proper control of the solution composition and formation conditions the fibers self-assemble. The diameter of the resulting fibers can be adjusted over a range spanning from one to tens of microns. The core of the fiber retains all of the responsive properties associated with low molecular weight LCs. A nematic LC core's director aligns along the long axis of the fiber making them highly birefringent. An electric field applied across the fiber changes both the director alignment and the optical properties of the fiber. Alternatively, thermochromic fibers are formed using a cholesteric LC in the core. Unlike similar electro-spun fibers, the airbrushed fibers can be sprayed as continuous matts on virtually any surface or woven into textiles. The resulting fabrics can be made into displays, thermochromic temperature sensors, or for detection of chemical or biological agents. They offer numerous opportunities for wearable textiles that respond optically to a variety of stimuli.

 
Session L-4 - End Uses, Commercial and Applications

L-4:IL01  Practical Application of Side Emitting Optical Fibres
J. MILITKY, D. KREMENAKOVA, R. MISHRA, Textile Faculty, Dept. of Material Engineering, Liberec, Czech Republicy

The aim of this contribution is description of side emitting plastic optical fibres (SEPOF) basic properties and their efficient embedding into fibrous structures enabling active visibility. For preparation of textile structures containing SEPOF the braiding technology is used. Illumination system with light emitting diode (LED) is used as light source. Incorporation of side emitting POF into fibrous tube provides sufficient side emission intensity especially for POF with larger diameters. Typical applications are: • silhouette visualization in the dark conditions: useful for active visibility of road users, persons (jackets, school bags, handbags, backpacks), objects (cars, bikes, baby carriage, wheelchairs), animals (dog straps, horses bridle) • security lighting systems (cars outline, identifying of cars open doors in the dark, restrictions on roads) • setting of limits (parking barriers, end of carpets, stairs, etc.). • emergency lighting (hotels, hospitals) - lighting in corridors, lifts, edge visualization, etc. • highlight information • aesthetically complement Separate application area may require different color effects related to the design, creation creation of so-called emotional fabrics characterizing the mental state respectively feelings.


L-4:L02  Investigation of the Wetting Behaviour of Nanofunctionalised Wool Fabrics
M.J. COOK, J.H. JOHNSTON, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand

Hydrophobicity has been a popular area of research for many years. This may be due to the numerous benefits that can be gained by rendering a surface water repellent, such as increased self-cleaning and bacteriostatic properties. In textiles, superhydrophobic surfaces have been shown to be stain resistant, increasing the value of the textile in many markets. This work describes the results of an investigation into the nanofunctionalisation of merino wool fabrics & the effects this functionalisation has on the wetting behaviour of these samples. As hydrophobicity is affected by both the chemical and physical nature of a surface it was predicted that the wetting behaviours would be significantly altered. Nanoparticle-wool composites were synthesised via nanofunctionalisation of woven & knitted merino wool fabrics. Through the process of nanofunctionalisation the samples were not only chemically modified but also physically modified through some degree of felting due to handling and increased surface roughness from the nanoparticles themselves. The wetting behaviours of these composite fabrics were investigated to determine effects of both the chemical and physical modifications via nanofunctionalisation with respect to the hydrophobicity of the wool surfaces.


L-4:L03  Composites based on Graphene Nanoplatelets in Screen-printable Textiles Electronics
A. KURCZEWSKA, M. SŁOMA, Central Institute for Labour Protection-National Research Institute, Lodz, Poland

Within the last few years more and more effort was made to construct smart, textiles, clothing and wearable electronics. It requires new solutions in materials especially textile electronics. In the paper research aimed at working out electroconductive paths for connection of sensors, actuators and control unit in textile system or intelligent clothing was presented. The work concentrated on developing different pastes containing silver nanoparticles and carbon (graphene, nanotubes, graphite) that were used to obtain electroconductive paths on textiles by means of screen printing method. The paper contains the test results including electric resistance before and after the maintenance cycles as well as current carrying capacity of developed paths.
 

L-4:L04  Color Tuning in Electroluminescent Textiles
E. LEMPA, C. GRASSMANN, M. RABE, Niederrhein University of Applied Sciences, Research Insititute for Textile and Clothing, Moenchengladbach, Germany; A. KITZIG, E. NAROSKA, Niederrhein University of Applied Sciences, Institute for Pattern Recognition, Krefeld, Germany

Currently electroluminescent (EL) devices on film, paper or textile are based on a capacitor with one transparent electrode and one generally non-transparent, highly conductive electrode and a light-emitting dielectric layer in-between. The light-emitting pigments are mostly based on doped zinc sulfide. Currently available commercial products contain encapsulated pigments dispersed in organic solvents. Those dispersions allow EL-devices illuminating solitary in the colors white, green, blue-green, blue and orange. Blending those pigments lead to numerous new colors however, always linked to loss of brightness in the final device. In the research work the combination of fluorescent organic and inorganic dyestuffs with those inorganic EL-phosphors was investigated. As the EL-devices were all applied to textile materials, all dispersions were free of organic solvents. Special focus was directed to the concentration of dyes in an additional layer within the EL-device as well as the thickness and particularly the positioning of the layer. In the result colors were achieved, which cannot be found blending the phosphors, such as yellow and red. In addition, depending on the type of added dyestuff layer, the brightness could be increased, which is not possible with blending phosphors.


L-4:L05  Design Proposal of Space Clothes that Supports Lives in the Future Space Tourism Era
M. OHKUBO¹, M. YAMAMURA², J. KANEBAKO², L. ISHIGAMI², M. XUE¹, T. NOJIMA¹, S. YAMAGUCHI³, H. UCHIYAMA², N. YAMAZAKI^2,4, ¹University of Electro-Communications, Japan; ²Joshibi University of Art and Design, Japan; ³Filmmaker; ⁴Astronaut

In a near future, many people will be able to visit and stay in the space hotels more easily than now days. In this situation, novel clothes that fit to the special environment will be required. In this paper, we describe the detail of a prototype of “space clothes”, a new clothes design that could solve the appearance and functionality conflicts shown below. ・Appearance Conventional clothes especially skirt and loosely designed shirts are often difficult to be worn in space because it restricts wearer’s motion. This will be a main condition to be considered when designing space clothes. On the other hand, such clothes are often preferred by women because of their elegance. This conflict should be resolved when designing future clothes in space for women. ・Display of wearer’s inner status and surrounding environment Space sickness and sunburns by ultraviolet rays will be big issues for the space tourists. To cope with the space sickness issue, we have developed an inner status display named Bio-collar[Nojima et al. 2015]. That is designed to indicate the wearer’s heart rate through its kinetic motion and glittering color. We believe that this paper could be a good opportunity to initiate the discussion to clear new market of clothes in space.


L-4:IL07  Electrospun Drug-loaded Textiles for Biomedical and Healthcare Applications
I. BONADIES, Institute for Polymers, Composites and Biomaterials (IPCB), CNR, Pozzuoli (Na), Italy

Electrospinning is a versatile technology for the production of polymer micro/nano scale fibers. This technology provides the opportunity for direct addition of bioactive payloads into micro/nanofibers thus improving the encapsulation efficiency and reducing the burst release via proper selection of drug-polymer-solvent system or electrospinning setup. In addition, since electrospun fibers have one dimension at the microscopic scale but another dimension at the macroscopic one, it is possible to combine the advantages possessed by functional materials on the nano-meter scale, i.e. a large surface to volume ratio, with the properties of conventional solid membranes, such as ease of manipulation and applicability in any size and shape, making them suitable for biomedical or healthcare applications both topically (i.e. skin) and locally (i.e. tumor). This communication deals with electrospun fibrous systems containing active compounds extracts from plants such as Artemisinin; these systems have been properly realized to preserve the pharmacological activity of drugs and evaluated as potential delivery systems for vector-born deseases and cancer, reducing the damage to non-target organism and environment.


L-4:L08  Electroluminescent Textile for Therapeutic Applications
C. GRASSMANN, E. LEMPA, M. RABE, Niederrhein University of Applied Sciences, Research Institute for Textile and Clothing, Moenchengladbach, Germany; A. KITZIG, E. NAROSKA, Niederrhein University of Applied Sciences, Institute for Pattern Recognition, Krefeld, Germany; B. NEUKIRCH, Niederrhein University of Applied Sciences, Faculty of Health Care, Krefeld, Germany

Alternating-current (AC) electroluminescent (EL) devices on fabrics with high brightness are presented. The EL-devices were fabricated via knife coating; inorganic luminous pigments are based on zinc sulfide. Effects of parameters influencing the brightness were investigated. These parameters are the AC-voltage, AC-frequency, AC-waveform, layer composition of the luminous capacitor and the fabric. Introducing a reflecting dielectric layer enhances the light yield to more than 1,200 lx on a fine woven fabric with green luminous pigment. This can be achieved with small concentrations of reflective white pigments such as titanium dioxide, maintaining the flexibility and bendability of the textile substrate. The produced luminous textiles are investigated as a possible replacement for light boxes used in the therapy of seasonal affective disorder (SAD). A high brightness of more than 1,000 lx and a high portion of short and energy rich wavelengths is necessary for the treatment. Contrarily to state-of-the-art light boxes a higher acceptance of light therapy is expected, because a luminous textile can be integrated easily and unremarkably into the living environment.


L-4:L09  Soft Condensed Matter Hybrid Fiber Sensors for Motion Detection and Vital Funtions
M. MELNYKOWYCZ, F. CLEMENS, Empa Materials Science and Technology, Dubendorf, Switzerland; M. TSCHUDIN, STBL Medical Research AG, Wilen, Switzerland

Soft condensed matter hybrid fiber sensors based on a Carbon Black (CB) and TPE have been produced in order to measure the deformation of textile bands applied in wearable computing applications. By modifying the stiffness regions of the band with adhesive materials, the sensing function of the band sensor can be tuned. Mechanical testing has shown that the band sensor shows some relaxation during loading to different strain levels, but has very low electrical signal drift over time for strain monitoring. Mechanical characterization of the piezoresistive sensor (in 0.3 mm diameter monofilaments) has shown a decoupling between the non-linear force and a linear electrical resistance response during tensile loading. The CB/TPE sensor material can achieve ultimate strains of over 150%, with a safe working range up to 100%. Pre-straining of the material is required in order to improve the sensor performance. The current work will shown the ability to build a band sensor for strain monitoring based on a soft condensed matter sensor based on CB/TPE hybrid material which can act as a motion capture and pulse-wave monitoring sensor. Flexible and customizable integration approach is required in order to provide high quality sensor data.
 
 
Poster Presentations

L:P04  Smart Fabric Design and Printing Platform
B. POPOV, T. TODOROV, V. MARINOV, S. STOYANOV, V. TODOROV, Grafixoft, Sofia, Bulgaria; R. TORAH, Y. WEI, N. GRABHAM, Y. LI, J. TUDOR, Department of Electronics and Computer Science, University of Southampton, Southampton, UK

Smart Fabrics are conventional fabrics to which electronic functionality is added to achieve sensing or enhance their appearance. We present a software and hardware printing platform enabling designers to design and realise smart fabrics without the need for technical expertise in smart fabrics. This removes a major barrier to the wider exploitation of smart fabrics. The software platform has 3 stages: • The ‘Design tool’ enables designers to create colour images and add smart functional elements for light emission, colour change, sound emission and proximity/touch sensing. • The ‘Translation Tool’ converts the user generated design into the required printed layers necessary to achieve the smart fabric realisation using conventional inkjet colour inks and electronic inks for the smart functions. • The ‘Visualisation Tool’ allows the user to see and adjust a visual representation of the appearance of the final smart fabric before printing. Parameters can be set to control the smart fabric’s functions such as electroluminescent lamp brightness. Once designed the smart fabric can be printed using a bespoke direct write printer. The paper will present the software, developed at Grafixoft, the printer hardware developed at the University of Southampton, and example smart fabrics.