Interactive textiles today
Prof. Lieva Van Langenhove
Department of Textiles
Smart and electronic textiles?
Smart textile measures/reactsReaction is intrinsicReaction is controlled by electronicsActive data processing
Functions of smart textiles
• Sensor• Actuator • Data processing• Communication• Energy
Why textiles?
• All around• Versatile• Light weight• Large contact area with body• Comfortable• Easy to use
Effects from nano to macro
Objective
The textile can absorb, reflect, shield, measure or generate …
TemperatureHeat fluxElectromagnetic fieldsHumidityChemicalsGasesRadiation
Electric propertiesMovementForcesMechanical strengthOdourAcousticBiological
Electromagnetic fields: conductivetextiles
Stainlesssteel
Kevlarcoatedwith
Knitted Woven non woven
polypyrrol copper gold
Conductive textiles as sensor
Textrodes Respibelt
EMG monitoring
Myography for stress measurementContactless
Professional use
EMG sensorsembroidered
laminated
(www.context-project.org)
Electrotherapy
• Homogeneous currentdensity
• Electrode design• Current supply
• Contact with skin• Conditions of current
• Tactile stimulus• Skin stimulation
• Tissue reinforcement• Sensory effects
• Muscle stimulation• Warming up• Exercising
•Drug delivery• Skin permeability• Iontophoresis
Current density must be homogeneous
Peak current density: 33 mA/mm2
Uniform profile
Stripeprofile
Concentricsquare
21 mA/mm² 15.6 mA/mm2
Electrotherapy prototypes
Heating
Polar Sefar
Cooling
• Grado Zero F1 pilots• Prospie project:
• Salts that cool when wetted• Ventilation in clothing• Phase change materials
www.prospie.eu
Self adapting insulation/ventilation
Biomimetics: based on pine coneCoating reacting onhumidity
G. JenonimidisUniversity of reading UK
Phase change materials
•Developed by NASA in 90’s•Cope with large temperature variations•More than 500 substances•Uses melting heat: about 200 times higher thancaloric value•Paraffin waxes in micro capsules
Thermoregulation challenges
• Sensors • Determining thermal comfort• Adequate control strategies• Actuators:
• Cooling• Insulation• Ventilation
Mechanical actuators
Mechanisms
Thermal/hygral expansionShape memory materialsGel based systemsElectro active polymersElectrostrictive systems
Status
Limited flexibilityOne way, expensive, controlBased on diffusion: slowSlow, low voltageFast, high voltage
Shape memory alloys: Nitinol
Goes to a predifinedshape above transitiontemperature
Grado ZeroSelf ironing shirt
Smart interface: active dyes
skin pH
days
Skin pH-variation after burn wound
L. Van der Schueren, K. De Clerck
Textile display
France Telecom
Built in LED
Lumalive
OLED
Textile structureOrganic materialsImage qualityYieldOxidation
TITV
Biochemical actuators
Micro capsules Active gels Cyclodextrins
Communication
Within componentsBetween components in a suit‣ Conductive fibres‣ Optical fibres
With the wearer: • keyboard, • display
Wide environment: • inductive, • antenna
Energy
Optimise consumption and distributionBalance between storage and “generation”Storage:
• Flexible chemical batteries• Capacity based fibre batteries
Generation from:• Heat• Motion• Light
Energy from heat: Seebeck
Uses:•P semiconductor•N semiconductor•Conductive materials
Infineon demonstrator
Areas of cooling
Areas of heating
Energy from motion: piezo electrics
Deformation leads to E fieldNeeds large surface, nothicknessPVDFChallenges:•Materials•Concepts•Production (poling)Electrode
Piezo electric layerElectrode
Photovoltaics
Organic photovoltaicsNanostructuresDyestuffsChallenges:•Materials•Production•Stability•Concept
Transparent layer/ Electrode
N semiconductor
P semiconductor
Electrode
+ -+ -
+ -
STELLA: Stretchable Electronicswww.stella-project.eu
Creating the paths: Sefar
Inner garment
Outer garment
Accelerometers
GPSAntenna
TextileAntenna
Flexible Battery
ExternalTemperature
Alarm
DataRecording
Processing Transmission
Victim patch
Parameter
•Heart beat rate
•Respiratory rate
•Body Temperature
Cfr. inner garment
Monitoring Centre
GPS
Position ProeTEX PDA Google Earth
145.202740 45.202624 45.202755
09.133803 09.133932 09.133844
245.203345 45.203210 45.203322
09.134353 09.134457 09.137197
345.201181 45.201847 45.201555
09.139856 09.139828 09.139477
445.200705 45.198690 45.198816
09.143692 09.143832 09.143833
A smart textile can …
Monitor man, the environment and itselfDetect unusual conditionsDetect when things risk to get out of handPrevent things from happeningProtect against accidentsMonitor the impact of eventsProvide early assistanceSupport and follow up rehabilitation
www. .eu
Coordination action for enhancing the breakthrough of intelligent textile systems (e-textiles and wearable Microsystems)
www. .org
COLAE: Commercialisation Clusters of OLAE