Symposium Organizers
Dermot Diamond Dublin City University
Xiaoming Tao Hong Kong Polytechnic University
Gerhard Troester ETH Zurich
S1: New Materials and Fibers
Session Chairs
Tuesday PM, April 18, 2006
Room 2009 (Moscone West)
9:30 AM - **S1.1
Electronic Textiles Based On Intrinsically Conducting Polymer Fibre.
Benjamin Mattes 1
1 Corporate, Santa Fe Science & Technology Inc., Santa Fe, New Mexico, United States
Show AbstractMethods for the commercial production of Panion fibre, which is prepared from the electrically conducting polymer polyaniline, have been achieved. This specialty electro-active fibre has a volume conductivity of 1,000 Ω-1 cm-1, modulus of 5 GPa, tenacity of 200 MPa, and a stress at break of 12%. Measurement of the DC resistivity and thermopower taken from room temperature to liquid helium temperature proves that these “all-plastic” synthetic fibres reside on the metallic side of the insulator-metal phase boundary. The fibre may be dopant exchanged with any acid to achieve desired sets of physical properties. Panion fibre coating technology has been developed to prevent “dopant leeching” from the material during repetitive wash and wear cycles. Yarns are easily fabricated from the produced fibres. We have designed wearable textile and technical fabrics from Panion fibre and yarns. Composite fabric is easily prepared with Panion and other conventional electrically insulating fibres, e.g., Nylon®, Lycra®, and silk on conventional textile processing equipment, e.g., weaving, knitting, stitching, and braiding machines. Panion is purposefully placed in the composite fabric to create electronic circuits, distributed sensor arrays and networks, to deliver power, and to achieve the functions of mechanical actuation, resistive heating, and energy storage. Conducting polymer fibre and yarns are well positioned to serve as a platform technology for the emerging markets of Smart Fabric and Interactive Textiles. Additionally, Panion nanofibre is readily prepared by electrostatic spinning techniques.
10:00 AM - **S1.2
Functionalisation of Textiles with Nanotechnology
Eckhard Schollmeyer 1 , Torsten Textor 1 , Katarzyna Haenni-Ciunel 1 , Frank Schroeter 1
1 , German Textile Research Center, Krefeld Germany
Show Abstract10:30 AM - S1: Materials
BREAK
11:00 AM - S1.3
Synthesis and Nanomechanical Studies of Biomimetic Polymers Having Well-defined Nanostructures for Advanced Mechanical Properties
Zhibin Guan 1 , Jason Roland 1 , Keunchan Oh 1
1 Department of Chemistry, University of California, Irvine, Irvine, California, United States
Show AbstractNature has shown us many elegant designs of fibrous materials that combine mechanical strength, fracture toughness, and elasticity. Advanced studies including single molecule studies of these biological materials have revealed that their well-defined nanostructures often play pivotal roles for their advanced mechanical properties. Inspired by nature, one major research thrust of my group is to develop synthetic polymeric materials to mimic both the structures and functional properties of biological systems. In one example, we use a skeletal muscle protein, titin, as the model to develop modular multi-domain polymers. Single molecule nanomechanical studies on titin and other modular proteins suggest that these exceptional properties arise from a modular elongation mechanism. The sequential unfolding allows modular biopolymers to sustain a large force over the whole extension of the chain, which makes the polymer strong, along with a large area under the force-extension curve, making it tough as well. Our laboratory has developed a number of synthetic polymers having modular multidomain structures. The mechanical properties of the synthetic modular polymers are studied both at single-molecule level using atomic force microscopy (AFM) and bulk level using Instron. In another example, we use silk as model to develop synthetic polymers having extended beta-sheet structures. To achieve this goal, we first developed an efficient and convergent strategy for constructing a new beta-turn mimic. We utilized the facile azide-alkyne cycloaddition to construct a new triazole ring based beta-turn mimic. Upon mixing two peptides derivatized with terminal azide and alkyne, respectively, the two strands are ligated by formation of triazole ring which induces the formation of beta-turn. Currently we are applying this methodology to the design of polymers with extensive beta-sheet structures. The design concepts, synthesis, and physical studies of both systems will be discussed in this talk.
11:15 AM - S1.4
Viral Platforms for Genetically Functionalized Fibers
Chung-Yi Chiang 1 , Charlene Mello 2 , Jiji Gu 1 , Krystyn Van Vliet 1 , Angela Belcher 1
1 Materials Science and Engineering, M.I.T., Cambridge, Massachusetts, United States, 2 , U.S. Natick Soldier Center, Natick, Massachusetts, United States
Show AbstractInspired by the synthesis routes and properties of natural fibers, we have used liquid crystalline solutions of virus as precursors to fabricate functional fibers. The filamentous virus used herein is M13 bacteriophage, which is about 880 nm in length and 6 - 7 nm in diameter. Along the virus axis are 2,700 copies of pVIII proteins with functionalities that can be altered via modification of the viral genome to, for example, bind or nucleate specific inorganic materials. This technique has been used to produce metallic (e.g., Au) and semiconducting (e.g., ZnS) virus-based nanoarchitectures including nanowires. The ease of modifying the M13 bacteriophage genome makes this virus an attractive versatile platform for growth and assembly of a variety of materials. With a specifically assigned functionality, the engineered M13 filamentous viruses can be spun into nano- to micro-fibers. Here, the capabilities of the genetically engineered viral fibers for mineralizing inorganic materials at room temperature are demonstrated, and fundamental thermal and mechanical properties are examined. Scanning electron microscopy (SEM) and elemental analysis X-ray imaging (EAX) were employed to analyze the surface structures and biomineralization on the viral fibers. Thermogravimetric analysis (TGA) was used to examine the thermal stabilities and decomposition behaviors of the viral fibers. Uniaxial tension was used to quantify Young’s modulus, tensile strength, viscoelasticity, and fracture mode. The Young’s modulus of the viral fiber is 1 – 4 GPa and the tensile strength is 10 – 40 MPa. Compared with other commercialized polymers such as nylon 66, the viral fibers have competitive mechanical toughness and strength, indicating that this filamentous virus can be easily integrated or applied into current fibril manufacturing systems. The diversity given by the genetic manipulation of chemical functionalities on the viral fibers offers powerful toolkits for conjugating organic or inorganic molecules for a variety of potential applications such as anti-microbial, catalytic, optical, and electronic fibers.
11:30 AM - S1.5
Drawing of Hollow, Multilayered All-polymer Fibers for Smart Textile Applications.
Elio Pone 1 , Suzanne Lacroix 1 , Charles Dubois 2 , Maksim Skorobogatiy 1
1 Genie Physique, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada, 2 Genie Chimique, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada
Show Abstract11:45 AM - S1.6
Self-assembled Shape Memory Fibers of Triblock Liquid Crystal Polymers.
Samit Ahir 1 , Ali Tajbakhsh 1 , Eugene Terentjev 1
1 Physics, Cambridge University, Cambridge United Kingdom
Show AbstractS2: In-Room Poster Session: New Materials and Fibers
Session Chairs
Tuesday PM, April 18, 2006
Room 2009 (Moscone West)
12:00 PM - S2.1
Electro-Actuation of Shape Memory Polyurethane-Carbon Nanotube Composites Prepared by In-Situ Polymerization.
Jae Whan Cho 1 , Hye Jin Yoo 1 , Yong Chae Jung 1
1 Department of Textile Engineering, Konkuk University, Seoul Korea (the Republic of)
Show Abstract12:00 PM - S2.2
Ultrasound-induced Functionalization and Solubilization of Carbon Nanotubes for Potential Nanotextiles Applications.
Wei Chen 1 , XiaoMing Tao 1
1 Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong Hong Kong
Show AbstractAs a result of their unique architecture and remarkable mechanical and electrical properties, carbon nanotubes (CNT) have great potentials for applications in novel energy-storing “electronic textiles”, bulletproof vests, and artificial muscles etc. The promising applications, however, remain largely unexploited because of their poor dispersibility and problems of processability. Extensive research towards any modification of the CNTs that could improve their handling has been carried out. Major effort so far has involved conventional chemical techniques. The severe, tedious and time-consuming multiple-step reactions, however, made it difficult to pave the way for large-scale functionalization and thus for practical use. Recently, a novel sonochemical CNT functionalization approach has been developed in our laboratory. By employing the multiple effects of sonication, rapid and effective ultrasonically initiated in-situ polymerization of methyl methacrylate from nanotube convex surface has been demonstrated, and the resultant polymer-grafted carbon nanotube are soluble in various solvents such as chloroform, dichloromethane, tetrahydrofuran, toluene and so on. In comparison with the conventional methods, the in-situ sonochemical technique displays the following merits: (1) both debundling and of CNT ropes, dispersion, activation, initiation and polymer attachment can be achieved simultaneously and quickly in a single step; (2) using ultrasound it is possible to carry out radical-polymerization without adding any initiator or catalysis; (3) the simple strategy may readily be extended to a range of other vinyl polymers, block-graft polymers and others. Details in preparations, characterizations and mechanisms of the simple functionalization of carbon nanotubes via ultrasonically initiated in-situ bulk and in-situ emulsion polymerization will be reported and discussed in this paper.
12:00 PM - S2.3
Suspension of Silver Oxide Nanoparticles in Chitosan Solution and its Antibacterial Activity in Cotton Fabrics
Zhigang Hu 1 , Winglai Chan 2 , Yaushan Szeto 1 , Tingjin Ye 1
1 Institute of Textiles and Clothing, The Hong Kong Polytechnic Univeristy, Hong Kong Hong Kong, 2 Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic Univeristy, Hong Kong Hong Kong
Show Abstract12:00 PM - S2.4
Field-effect Transistors of Tetracene Single Crystal on top of a Flexible Substrate.
Chang Seoul 1 , Taeheon Kim 1 , Joonho Lee 1 , Jinheon Kim 1
1 Advanced Fiber Engineering, Inha University, Incheon Korea (the Republic of)
Show Abstract12:00 PM - S2.5
Fabrication of Ag Nanoparticles/poly(3,4-ethylenedioxythiophene) Nanocomposite Electrodes by Ink-jet Printing.
Chang Seoul 1 , Joonho Lee 1 , Taeheon Kim 1 , Jinheon Kim 1
1 Advanced Fiber Engineering, Inha University, Incheon Korea (the Republic of)
Show Abstract12:00 PM - S2.6
Size Dependent Twisting of Carbon Nanotube Ropes.
Moneesh Upmanyu 1 , Haiyi Liang 1
1 Engineering Division, Materials Science Program, Colorado School of Mines, Golden, Colorado, United States
Show AbstractTo date, synthesis of crystalline carbon nanotube ropes has been limited to nanometer radii. We employ a coarse-grained mechanics model based on Van der Waals interactions between nanotubes to show that large radii ropes are unstable with respect to intrinsic bulk twisting. At a critical rope radius, the elastic energy expended in bending and torsion of individual nanotubes to form the twisted rope is fully compensated by increase in crystal cohesive energy due to enhanced inter-tube interaction. We show that twist and overtwist is strongly coupled to mechanical properties of ropes and should be factored in textile applications . At thicker rope radii, it is energetically favorable for the rope to dissemble (peel off) into thinner ropes. Based on these results, we argue that inter-tube cross-linking during growth is essential for synthesis of bulk carbon nanotube crystals.
S3: New Materials and Fibers
Session Chairs
Tuesday PM, April 18, 2006
Room 2009 (Moscone West)
2:30 PM - **S3.1
Functional Self-Reinforced Composites using Stereocomplex Fibers
Mohan Srinivasarao 1 2 , Matija Crne 2 , Jung Park 1
1 School of Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, Altanta, Georgia, United States, 2 School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractPolymeric materials are used in a variety of applications ranging from the use of poly(methylmethacrylates) in medical applications as bone cement to high strength composites for the wings of certain aircrafts to components in high end tennis racquets. The choice of polymeric materials is due to the fact that they can be processed rather easily, shaped into a variety of shapes using simple thermal processing methods and also due to structural diversity of polymeric materials that are available or can be synthesized. A great attraction for these materials is based on the fact that a given polymeric material can be processed differently to possess high strength or low strength – an example is the simplest polymer polyethylene: it can be processed by gel spinning methods to produce high strength fibers that are comparable in strength to materials like Kevlar that are used in bullet proof vests or can be processed to form extremely low strength objects like garbage bags. Among the many polymers, PMMA has been found to be biocompatible and hence has been used as a biocompatible polymer. One of the main applications for PMMA, often used as a copolymer with styrene, is as a grouting material in total joint arthroplasty. PMMA, known as bone cement, was and is still instrumental in the success of cemented total joint arthroplasty for the treatment of arthritis and other degenerative joint diseases. The long-term survivability of PMMA has been rather limited due to the inherently poor mechanical properties and the presence of voids in the processed composites and stress concentration points. It has been shown in clinical studies that bone cement failure either at the interface or through the cement over a period of several years is one of the major causes of implant failure. Cement fracturing has been attributed to a variety of factors which include low strength at the cement-prosthesis and cement-bone interface, porosity in the cement mantle, failure at the matrix-fiber interface among others. In order to alleviate these problems the concept of self-reinforced composites was introduced. In this talk we extend this to a novel concept of using the stereochemistry of polymers to form stereocomplex fibers with the ultimate aim of making these materials of use in prosthetic devices.
3:00 PM - **S3.2
Wearable Energy Conversion and Storage Systems: Novel Fibres and New Approaches
Gordon Wallace 1
1 IPRI, University of Wollongong, Wollongong, New South Wales, Australia
Show AbstractThe identification of light weight materials capable of transforming and/or storing energy is critical to the development of the emerging field of electronic textiles. Organic conductors such as carbon nanotubes and inherently conducting polymers are “putting their hand up” for consideration. The inherent energy conversion capabilities such as their photoelectrochemical and electromechanical properties are of interest, as is their ability to store energy when configured as a capacitor or battery.To achieve the ultimate goal : integration of these materials and structures into textiles and garments, these materials must be produced in appropriate forms – with continuous fibres perhaps being the most appropriate. Here we will present our recent findings on the properties of novel conducting polymer fibres containing carbon nanotubes (CNTs) as well as CNT based fibres themselves. The properties of these fibres with respect to their performance as artificial muscle fibres as well as fibre batteries will be discussed.
3:30 PM - S3: Materials
BREAK
4:00 PM - S3.3
Novel Continuous Poly(vinylidene fluoride) Nanofibers
Yuris Dzenis 1 , Xi Ren 1
1 Engineering Mechanics, University of Nebraska-Lincoln, Lincoln, Nebraska, United States
Show AbstractPoly(vinylidene fluoride) (PVDF) is well known for its excellent piezoelectric and ferroelectric properties. Currently, this polymer is used in applications mostly in the form of films. PVDF fibers open up exciting opportunities for design and use of active textiles. Fiber properties usually improve substantially with the decrease of their diameter and there is a great interest in continuous fibers of submicron diameters. However, conventional mechanical fiber spinning processes cannot produce fibers smaller than about 2 microns. In this work, ultrafine PVDF nanofibers were fabricated by electrospinning method [1]. The method consists of spinning polymer solutions in high electric fields. Parametric studies of the effects of molecular weight, solvent, solution viscosity, and surface tension on nanofiber diameter and morphology were conducted. XRD and FTIR analyses of PVDF nanofibers were performed. The latter indicated that the as-spun nanofibers consist mostly of the beta phase. As this phase is primarily responsible for the piezo- and ferroelectric response of PVDF, the latter result is very encouraging. The novel continuous PVDF nanofibers may be used in future nanostructured and active textiles and other applications as actuators and sensors. [1] Dzenis, Y. Spinning Continuous Fibers for Nanotechnology. Science, 2004, Vol. 304, 1917-1919
4:15 PM - S3.4
The Electrical Percolation Transition in Carbon Nanotube/polymer Fibres: A Mesoscale Modeling and Experimental Study.
Sameer Rahatekar 1 , Milo Shaffer 2 , James Elliott 1
1 Materials Science and Mettalurgy, University of Cambridge, Cambridge United Kingdom, 2 Department of Chemistry, Imperial college London, London United Kingdom
Show Abstract4:30 PM - S3.5
Controlled Conductive Coating on Wood Microfibers via Layer-by-Layer Nanoassembly
Mangilal Agarwal 1 , John McDonald 1 , Yuri Lvov 1 , Kody Varahramyan 1
1 Institute for Micromanufacturing, Louisiana Tech University, Ruston, Louisiana, United States
Show AbstractThis paper reports a layer-by-layer self-assembly of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)PEDOT-PSS)on lignocellulose wood fibers to make conducting papers. Polycations-poly(allylamine Hydrochloride) (PAH) and poly(ethyleneimine) (PEI) were used in alternation with polyanionic PEDOT-PSS to construct the multilayer architecture. The surface morphology of the fibers was studied using roughness step tester (RST) and surface profilometer (TENCOR). Thickness of the coated film was estimated using quartz crystal micro-balance. Current – Voltage characterization was done using Keithley measurement system after every self-assembly step of PEDOT-PSS to study the electrical properties of the film. It was observed that the conductivity of the fiber increased with increasing layers of PEDOT-PSS. The measured conductivities ranged from 1E-3 to 5E-3 S/cm for unbeaten fibers and 1 to 10 S/cm for beaten fibers. It was also observed that the conductivity of the fibers (i.e., coating of the PEDOT-PSS layer) depends upon the type of polycations used to form the multilayer. In this work we are developing scale integration from nano, to micro and to macro (nanocoating-microfibers-macropaper). The results obtained show great promise for the development of smart paper technology and its contribution to the economic development of the nation.
S4: In-Room Poster Session: New Materials and Fibers
Session Chairs
Tuesday PM, April 18, 2006
Room 2009 (Moscone West)
5:00 PM - S4.1
Treatment of Cotton Fabrics by TiO2@Chitosan Hybrid Nanoparticles.
Xianqiong Chen 1 , Yuyang Liu 1 , John H. Xin 1
1 Nanotechnology Center, Institute of Textiles & Clothing, The Hong Kong Polytechnic University, Hong Kong Hong Kong
Show Abstract5:00 PM - S4.2
Copy the Microstructures of Lotus-leaf onto Cotton Fabrics.
Yuyang Liu 1 , Xianqiong Chen 1 , J. H. Xin 1
1 Institute of Textiles and Clothing, Nanotechnology Center, Hong Kong China
Show Abstract5:00 PM - S4.3
Modified Cotton Fiber Surface for Apatite Growth and Cell Affinity.
Bin Fei 1 , Shing Shun Tony To 2 , John H. Xin 1
1 Institute of Textiles & Clothing, The Hong Kong Polytechnic University, Hong Kong China, 2 Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong China
Show Abstract5:00 PM - S4.4
Dual-functional Emulsions for Textiles Nano-finishing.
Bin Fei 1 , John H. Xin 1
1 , Institute of Textile & Clothing, The Hong Kong Polytechnic University, Hong Kong Hong Kong
Show Abstract5:00 PM - S4.5
Wireless-based Monitoring of Body Movements Using Wearable Sensors.
Sarah Brady 1 , Shirley Coyle 1 , Dermot Diamond 1
1 Adaptive Information Cluster, National Centre for Sensor Research, Dublin City University, Dublin 9 Ireland
Show Abstract5:00 PM - S4.6
Investigation of Temperature Regulation Properties of Fabric Containing Microencapsulated Phase Change Materials.
Haifeng Shi 1 2 , Xingxiang Zhang 1 , Xuechen Wang 1 , Jianjin Niu 1
1 , Institute of Functional Fiber, Tianjin Polytechnic University, Tianjin China, 2 , Institute of Textile and Clothing, The Hong Kong Polytechnic Unversity,Hung Hom, Kowloon, Hong Kong, Hong Kong Hong Kong
Show Abstract5:00 PM - S4.7
Prediction of Fiber Die Coating Thickness
An Yang 1 , Ming Tao 1 , Yin Chen 1
1 Institute of Textiles and Clothing, Hongkong Polytechnic University, Hongkong Hong Kong
Show AbstractFiber coating is an effective way to impart smartness to a fiber. Die coating is a process that utilizes a die to control the thickness and concentricity of the coating layer. In the present work the die coating mechanism is studied numerically. A mathematical model for the fiber coating thickness has been developed. Compared with the previous work, the proposed model considers the effect of gravity force to get the general solution. The shear rate acting on the fiber surface is proportional to the fiber draw speed in an unpressurized applicator and can be minimized in a pressurized applicator through the applied external pressure. A serials of experiments using open-cup and pressurized applicators have been designed and conducted to measure simultaneously the coating speed and coating thickness in the coating process. It was found that the gravity may be an important driving force for the coating flow when the drawing velocity is small and the viscous force decreases, but may be relatively insignificant for high speed coating process. The calculated results were compared with the experimental data and a good agreement was obtained.
S5: Sensing
Session Chairs
Wednesday AM, April 19, 2006
Golden Gate A (Marriott)
9:00 PM - **S5.1
Multifunctional Carbon Nanotube Yarns And Self-Woven Nanotube Sheets By Solid-State Processing For Textile Applications.
Ray Baughman 1 , Mei Zhang 1 , Shaoli Fang 1 , Anvar Zakhidov 1 , Mike Kozlov 1 , Sergey Lee 1 , Ali Aliev 1 , C. D. Williams 1 , K. R. Atkinson 2
1 NanoTech Institute, University of Texas at Dallas, Richardson, Texas, United States, 2 Textile & Fibre Technology, CSIRO , Belmont, Victoria, Australia
Show AbstractWe describe novel methods for producing polymer-free carbon nanotube yarns and transparent sheets (self-assembled textiles), and describe their application as multifunctional textiles. These fabrication methods are conducted at room temperature in the solid state for multi-walled carbon nanotubes, which are much cheaper to produce that our previously used single-walled carbon nanotube fibers. The yarns have a maximum failure strength of above 460 MPa (850 MPa after polymer infiltration), they are highly resistant to creep and to knot or abrasion-induced failure, and they provide a giant Poisson’s ratio for stretch in the fiber direction. The nanotube self-woven textiles have higher gravimetric strength than the strongest steel sheet or the polymers used for ultralight air vehicles and proposed for solar sails. Applications evaluations are described for artificial muscles, thermal and light harvesting, energy storage, field-emission electron sources, electrically conducting appliqués, three types of lamps and displays, and sensors.
9:30 PM - S5.2
PPy-coated Electrically Conducting Fabrics with High Strain Sensitivity.
Pu Xue 1 , Xiaoming Tao 1 , H.Y. Tsang 1 , M.Y. Leung 1
1 , Hong Kong Polytechnic University, Hong Kong China
Show AbstractElectrically conductive textiles can be manufactured by coating textiles with conjugated polymer, thus imparting textiles electrically conductivity, meanwhile retaining their flexibility and durability. Polypyrrole (PPy) is most widely used conductive polymer for this purpose. Some reports also showed that polymerization carried out at low temperature yielded conducting coating with higher conductivities. In this study, we will report our recent research on electrically conducting nylon/spandex fabric obtained by chemically polymerising PPy at various temperatures and will emphasize its performance and investigate the mechanisms for sensing strain. Materials used includes the commercial multi-filaments of Polycaprolactam (PA6) supplied by Dupont, and polyurethane (PU) fibers (LycraTM) supplied by Sunikorn Knitters Limited (HK). Nylon/spandex knitted fabric supplied from Sunikorn Knitters Limited was composed of 83% Tactel and 17% PU (195 g/m2). The relationship between the strain and stress of the PPy-coated fabrics were obtained using an Instron testing machine (Model 4466) under the standard testing conditions (T=25oC and RH=65%). The results show that the strain sensitivity of the conductive fabric is over 400 at a strain of 50% for the samples prepared at low temperature, which is much higher than that of the samples prepared at room temperature and also much higher than those reported in the literatures. The mechanism of the excellent strain sensing behavior of PPy-coated electrically conducting fabrics was investigated by a Scanning Electron Microscopy (SEM) (Lecia Steroscan 440) integrating a material tester, which enables it possible to observe in situ the changes occurred on the surface of the specimen and record the load and displacement of the specimen while loading and unloading. The SEM microphotographs illustrated that coating layer on PA6 fibers can remain complete without apparent damage until the longitudinal strain reached about 25%. Once damage occurred on the surface of the fibers, it fractured abruptly. In contrast, for PPy-coated PU fibers, micro cracks appeared and gradually opened on the surface of fibers while the specimen was extended, and then closed while the specimen was recovered. The variation of the electric resistance mainly came from crack-opening and crack-closing mechanisms. It can be proposed that PPy-coated PU yarn played crucial role in the fabric with plating structure. The high conductivity and crack-opening and crack-closing mechanisms of PPy-coated PU yarn, as well as the fabric structure result in the high strain sensitivity of the PPy-coated fabrics.
9:45 PM - S5.3
Compliant Ferroelectret Touch Sensor for Prosthetic Skin.
Stephanie Lacour 1 , Ingrid Graz 2 , Martin Kaltenbrunner 2 , Christoph Keplinger 2 , Reinhard Schwodiauer 2 , Siegfried Bauer 2 , Sigurd Wagner 1
1 Electrical Engineering, Princeton University, Princeton, New Jersey, United States, 2 Soft-Matter Physics, Johannes Kepler University, Linz Austria
Show Abstract10:00 PM - S5.4
Piezoresistive Sensors on Textiles by Inkjet Printing and Electroless Plating.
Amit Sawhney 1 , Animesh Agrawal 1 , Prabir Patra 1 , Paul Calvert 1
1 Materials and Textiles, University of Massachusetts, Dartmouth, North Dartmouth, Massachusetts, United States
Show AbstractWe have printed arrays of strain sensors on textiles by inkjet printing of conducting lines and piezoresistive polymer (PEDOT) in order to provide detailed information about the response of a fabric in use. Conducting polymer has been printed onto polyamide and cellulose woven fabrics to form sensors using a modified HP inkjet print-head and X-Y linear positioning table. Good penetration and attachment is found on mercerized cotton but not on polyamide. Silver nitrate lines have been printed onto polyamide and converted to silver connectors by electroless plating. We observed that resistance of silver lines ranged from 0.7-1.5Ω/inch whereas for the conducting polymer it was 1-3 kΩ/inch by a four point probe method. The conducting polymer formed a surface coat on the fabric and also penetrated the weave. On stretching, the surface layer tended to crack but the embedded polymer acts as a strain gauge with a gauge factor of about 5. On the other hand the silver showed minimal change in resistance with stretching, as is required for connectors. Sensitivity towards temperature and humidity and the effect of orientation to stress and weave directions will be reported. Preliminary experiments show that these sensors attached to a sleeve could be effective for monitoring human joint motion.
10:15 PM - S5.5
A Single-layered Electrofabric as Flexible Pressure Mapping Sensor
Zhang Hui 1 2 , Tao Xiao Ming 1 , Li Xing Sheng 1 , Yu Tong Xi 3 , Wang Shan Yuan 2
1 Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong Hong Kong, 2 College of Textile, Dong Hua University, Shanghai, People's Republic of China, Shanghai China, 3 Department of Mechanical Engineering, Hong Kong University of Science and Technology, Hong Kong Hong Kong
Show AbstractWith recent development of wearable electronics, the need for a wide large area sensor has increased. Such sensors have to be elastic and possibly extendable to cover a three-dimensional surface, robust to work in harsh environment and reliable for accurate measurement. Fabric is a very appealing candidate for its elastic, deformable, low-cost, easy-fabrication, and wearable properties. This paper reports a single-layered resistive fabric pressure mapping sensor comprising by two orthogonally embroidered sensing yarns system. The pressure and position can be measured simultaneously using the sensing fabric system that is flexible, wearable, thin, and environmental stably. The sensing fabric can be connected to an acquisition system by Time Domain Multiplexing date processing device finally to display the pressure field over the sensing surface. The topology of the sensing elements distributed in the fabric can be set by patterning the conductive yarn systems using textile processes. The location of the pressure applied on the fabric can be identified by detecting the position where the change of the resistances occurs between two overlapped yarns. Meanwhile, the magnitude of the pressure can be acquired by measuring the variations of the resistance. The resistance vs. pressure curve exhibits a bilinear mode and the contacting resistance is unstable at the small pressure region but very stable at high pressure (>10Kpa). Note: Correspondence author,Tao Xiao Ming,Tel:27666470,Email:
[email protected]10:30 PM - S5.6
Optical Nano-textile Sensors Based on the Incorporation of Semiconducting and Metallic Nanoparticles into Optical Fibers.
Anuj Dhawan 1 , Arun Suresh 1 , Dennis Kekas 1 , John Muth 1 , Tushar Ghosh 2
1 Electrical and computer engineering, NC State University, Raleigh, North Carolina, United States, 2 College of Textiles, NC State University, Raleigh, North Carolina, United States
Show AbstractBy incorporating optical fiber based devices into woven and non-woven fabrics, one can be distribute these devices across large areas. Different kinds of fiber optic devices with nanofunctionality are being developed by incorporating metallic & semiconducting films and nanoparticles on and inside the optical fibers. Metallic films, mainly gold and silver films, between 2-16 nm thick were deposited on the tip and surface of multi-mode optical fibers to form surface plasmon sensors by electron beam deposition and annealing processes. Nano-particles developed from these films, by thermal and laser annealing procedures were then over-coated by a 0.5-4 µm thick silicon dioxide layer employing pulsed electron deposition. The over-coated fiber tip was then fused, using an electric arc fusion splicer, to another uncoated optical fiber to incorporate the nano-particles inside the fiber structure. This results in a continuous fiber that can be woven, or placed into nonwoven textiles. Pulsed laser deposition and pulsed electron deposition procedures were also employed to deposit semiconducting oxide films, mainly vanadium oxide on the tip and surface of optical fibers. The films are then annealed by plasma arc resulting in nanocrystalline materials which respond to temperature and environmental changes.
10:45 PM - S5.7
Introducing Sensing Capabilities to Fabrics
Dermot Diamond 1 , Shirley Coyle 1 , Sarah Brady 1
1 Adaptive Information Cluster, National Centre for Sensor Research, Dublin City University, Dublin Ireland
Show AbstractThrough life, the skin acts as an intermediary between the inner processes that govern the functioning of our bodies, and the outer world of our external environment through which we move. It is a remarkable organ, functioning as an impermeable barrier to most materials we come in contact with, yet allowing controlled passage of certain substances. Furthermore, it is a dynamic material, whose permeability can change dramatically depending on local or central (conscious) stimulii. It has very advanced sensing capabilities, generating signals to physical (touch, pressure, vibration..) or chemical stimuli through a densely distributed sensor network that can generate local feedback loops if necessary (e.g. touching a hot surface results in movement before the event has registered centrally).There is considerable interest in replicating some of these capabilities in ‘wearables’ through the integration of sensing capabilities with fabrics. The ideal scenario is where the textiles are functionalised to convey sensing capabilities directly to the fabric, rather than to attach various devices to the fabric. Considerable progress has already been made in that regard with respect to sensing of physical characteristics such as movement (e.g. bending of limbs, breathing etc.), but more sophisticated sensing of chemical and biological targets remains largely elusive.There are a number of reasons for this – partly it is due to the added complexity of these devices, but progress has also been inhibited by the lack of clear, market driven targets or applications for wearable chemo/bio-sensors. In terms of the complexity of these devices, there clearly are considerable opportunities for advanced materials whose properties can be tuned through molecular (nanoscaled) modifications. Properties that need to be considered for reliable chemical sensing include water permeability (sample transport), sensing capability, and release of standards (calibration). However, this is challenging research and as such, it needs a driving force to enable R&D investment to be justified. This raises the question of whether there are markets and specific targets emerging that will provide this driving force. Like skin, can fabrics provide a protective, early warning capability for people? If so, is it targeting internal parameters (i.e. our own personal health) or detecting potential external threats that may potentially affect our personal health? The answer is that both functions are required, and they are needed to varying degrees, depending on the personal circumstances of the wearer. The needs of an emergency-disaster worker and an elderly person living alone are completely different, as would be the needs of a young athlete training for a specialist sporting event.In this paper, I will address these issues and look at potential opportunities that may help to drive research into the development functionalised fabrics with integrated sensing capabilities.
11:00 PM - S5.8
Polypyrrole-coated Large Deformation Strain Fabric Sensor and its Properties Study.
Xiaoyin Cheng 1 , Hing Yee Joanna Tsang 1 , Yang Li 2 , Mei Yi Sarah Leung 1 , Xiaoming Tao 1 , Chun-wah Marcus Yuen 1 , Pu Xue 1
1 Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong China, 2 Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang Province, China
Show Abstract
Symposium Organizers
Dermot Diamond Dublin City University
Xiaoming Tao Hong Kong Polytechnic University
Gerhard Troester ETH Zurich
S6: Applications
Session Chairs
Wednesday AM, April 19, 2006
Room 2009 (Moscone West)
9:30 AM - **S6.1
E-textiles for Wearable Sensing, Actuation and Energy Harvesting.
Danilo De Rossi 1
1 Interdepartmental Research, Univ of Pisa,, Pisa Italy
Show AbstractIn this talk the author describes the early conception and latest developments of electroactive polymer (EAP) based sensors, actuators, electronic components and power sources, implemented as wearable devices for smart electronic textiles (e-textiles). Such textiles, functioning as multifunctional wearable human interfaces, are today considered relevant promoters of progress and useful tools in several biomedical fields, such as biomonitoring, rehabilitation and telemedicine. After a brief outline on ongoing research and the first products on e-textiles under commercial development, the most performing EAP based devices developed by our lab and other research groups for sensing, actuation, electronics and energy generation/storage will be discussed, with reference to their already-demonstrated or potential applicability to electronic textiles.
10:00 AM - S6.2
Antimicrobial Polymer Coating of Fabric by Initiated Chemical Vapor Deposition.
Tyler Martin 1 , Karen Gleason 1
1 Chemical Engineering, MIT, Cambridge, Massachusetts, United States
Show AbstractThin coatings of antimicrobial polymers have been synthesized by initiated chemical vapor deposition (iCVD) and can be applied to a wide range of substrates, including fragile materials that are sensitive to heat and/or solvents. This makes iCVD ideal for imparting antimicrobial properties to fabrics. Antimicrobial fabrics are of interest in military applications, such as biowarfare protection, self-decontaminating fabrics, undergarments for long term use on deployment, as well as civilian uses such as clothing for athletes and hikers, and textiles in hospital environments, including bedding, draping, and scrubs. Existing strategies for imparting antimicrobial properties to surfaces commonly employ an antimicrobial agent, such as silver ions or antibiotic drugs, which leaches out from the bulk material. However, the time of effectiveness will be limited as the agent will eventually be exhausted. The most prevalent non-leaching strategy is to permanently bond cationic quaternary ammonium polymers to the surface through covalent attachment. This work seeks to build on this non-leaching strategy by depositing a styrene-derivative polymer which contains a tertiary amino group with a pKa near 10 so that it is protonated to a cationic state at physiological conditions. The polymer deposition was optimized on flat substrates and the structure confirmed by FTIR. The coating was applied to dyed nylon fabric, and the surface and thickness was imaged by SEM. Coated samples of fabric were tested according to ASTM E2149-01. An iCVD coating of 39 µg/cm2 fabric (corresponding to a thickness of ~40 nm) was effective at killing E. coli; a 99.99% (4 log) reduction in viable bacteria was observed in just two minutes and a 99.9999% (6 log) reduction was observed in one hour. In addition, post-test sonication of coated samples have shown no viable bacteria adhered. The coating has also been successfully tested against the gram positive bacterium B. subtilis, showing ~6 log reduction of viable bacteria in one hour using thicker coatings. Initial demonstration of an all-vapor-phase covalent grafting scheme of the iCVD polymers to nylon was achieved using the type II photinitiator benzophenone.
10:15 AM - S6.3
Alginate Based Nanofibrous Structure: Scaffold in Tissue Engineering
Narayan Bhattarai 1 , Zhensheng Li 1 , Yii-Juang Chen 1 , Dennis Edmondson 1 , Miqin Zhang 1
1 Material Science and Engineering, University of Washington, Seattle, Washington, United States
Show AbstractPolymeric nanofibers that mimic the structure and function of the natural extracellular matrix (ECM) are of great interest in tissue engineering as scaffolding materials to restore, maintain or improve the function of human tissues. The natural ECMs in the body are mainly composed of proteoglycans and fibrous proteins with fiber diameters at the nanoscale. Electrospinning has been recently developed as an effective technique for nanofiber fabrication. In the present study we explored the electrospinning method to develop alginate-based nanofibers having an average fiber diameter controllable from submicrons down to few tens of nanometers with a narrow size distribution using the solutions containing alginate, polyethylene oxide (PEO), and Triton X-100™. The effect of processing conditions on fiber diameter, morphology, and physico-chemical properties were studied. Small amount of PEO or Triton X-100™ blended with the alginate considerably improve the spinnability of the alginate solution. Potential use of this nanofibrous matrix for tissue engineering was studied by examining the integrity of ionically crossliked nanofibrous mat in water, PBS, SBF and cell culture medium and the cellular compatibility. Results of the human chondrocytes seeded on electropsun nanofibers showed favorable cell-matrix interactions within the cellular construct. Cells on the nanofibrous structure proliferated well and maintained a phenotypic shape. Electrospining of alginate solutions provides a potential option for the fabrication of natural polymer-based biomaterial scaffolds with virtually unlimited resources.
10:30 AM - S6.4
Self-cleaning Cotton Fabrics
Kaihong Qi 1 , Walid Daoud 1 , Haozhong Xin 1
1 Institute of Textiles &Clothing, The Hong Kong Polytechnic University, Hong Kong China
Show AbstractNanocrystalline anatase titanium dioxide films were successfully produced on cotton fabrics from alkoxide solutions under ambient pressure using the low temperature sol-gel process. At a temperature as low as 40 centi-degree, only anatase phase formed from X-ray diffraction spectroscopy (XRD). Field scanning electron microscopy (FESEM) images show the formation of uniform continuous films of titanium dioxide on cotton fabrics. The self-cleaning properties of these fabrics were evaluated by measuring the degradation of acid blue dye Neolan Blue 2G used as a model compound. The results indicated that anatase treated-cotton fabrics exhibited much higher self-cleaning performance than those of amorphous TiO2-treated and untreated cotton fabrics.
10:45 AM - S6.5
Fibers with Controllable Magnetic Nanodomains for Positive Identification and Anti-couterfeiting Applications.
Melinda Satcher 2 , Carola Cuadro 3 , Carlos Rinaldi 3 , Juan Hinestroza 1
2 Textile Engineering, Chemistry and Science, NC State University, Raleigh, North Carolina, United States, 3 Chemical Engineering, University of Puerto Rico, Mayaguez, Puerto Rico, United States, 1 Fiber Science Program, Cornell University, Ithaca, New York, United States
Show Abstract11:00 AM - S6.6
Nanobiomaterials For Controlled Release Of Drugs & Vaccine Delivery.
Ashok Vaseashta 1 , Ioan Stamatin 2 , Arzum Erdem 3
1 Nanomaterials Processing & Characterization Laboratories, Physics & Physical Sciences, Marshall University, Huntington, West Virginia, United States, 2 3 Nano & Alternative Energy Sources Research Center, University of Bucharest, Faculty of Physics, Bucharest Romania, 3 Analytical Chemistry Department, Ege University, Izmir Turkey
Show AbstractIn this investigation, we present a comprehensive overview of our ongoing and future directions of research using inorganic and organic nanobiomaterials. We have employed biodegradable polymers for possible construction of excipient therapeutic templates. There are a number of natural and synthetic biodegradable polymers that are being used and are proposed for both soft and hard tissue repair. We have employed nonwoven matrices from poly (ε-caprolactone) (PCL) homopolymers and poly (L-lactide/ε-caprolactone) (PLLA/CL) copolymers by electrospinning process for possible applications in burn/wound dressings. Efforts are currently underway to control the release characteristics of these biodegradable fibers by varying aliphatic polyesters, i.e. hydrophobic poly (lactic acid) PLA and hydrophilic poly (glycolic acid) PGA. Such materials will have a profound effect on the time-controlled transport of vaccine to a specific site. These materials may also play a key role in developing novel chemotherapeutic agents that could be important in targeting specific genes and thus may provide selective control of gene expression. Furthermore, these fibers-by-design address many issues relating to the fundamental challenge in the synthesis of System-on-Fibers (SOF) and nanofiber materials to foster antibacterial and/or hygienic functionality and will have tremendous application in global security and defence. We will discuss issues relating to the sensitivity and scalability.