Mrs. Smita Deogaonkar-Baride & Mr. V. K. Shinde · Poly(phenylene-vinylene ) n n S n n Polypyrrole...
Transcript of Mrs. Smita Deogaonkar-Baride & Mr. V. K. Shinde · Poly(phenylene-vinylene ) n n S n n Polypyrrole...
The Bombay Textile Research Association
Mumbai
ASTM-Workshop on Smart Textiles,
Chicago,USA
26th June 2016
Development of Fabric Based Sensors for Smart Textile
Applications-Mrs. Smita Deogaonkar-Baride & Mr. V. K. Shinde
• BTRA was established in 1954 as research association by textile millowners of Mumbai to provide research and consultancy support toIndian Textile Industry.
• To undertake research and other scientific work in connection with thetextile trade or industry and other trades or industries allied therewith oraccessory thereto.
About BTRA
Technical Services
Consultancy in shop floor problems
Utilities /
Conservation
Quality &
Environment
Management
Decentralized
Sector
Training Services
Need based training on all
aspects of textiles/technic
al textiles
Research Projects
Government funded
Private funds &
In house
Testing Services
(ISO-17025)
Physical & chemical testing
Polymer & Eco-Parameters testing
Geotextiles Lab
Soil Mechanics
Lab
Technical textiles / composites testing
Microbiology
For more details-
Website-www.btraindia.com
-91-022-2500 -2652
-91-022-2500-3652
Main Activities
Source- A Roadmap on Smart Textiles- Textile Progress, June 2010
Communication
Data Processing
PoweringActuator
Sensor
Applications of Conductive Textiles
•Smart Textiles
Antistatic applications
Surface resistivity(ohm/sqr.):• Very Good : 106–108
• Good : 108–109
• Poor : 109-1010
• Insufficient : >1010
EMI Shielding
Efficiency w.r.t. Surface resistivity(S.R.)-• 0–20 dB: Low (S.R.-104)
• 20–40 dB: Average (S.R.- 1)• 40–70 dB: Good (S.R.-10-2)
• 70–90 dB: Excellent (S.R.-10-4)
•Resistive Heat Generation
Power Density (100mW/in2)•Smart Textiles
S.R. ≈ 100-1000 ohm/square
Low
Medium
High
Conductivity range * www.esd.org** A. Varesano et al. Synthetic Metals 159(2009) 1082- 1089***http://www.enthone.com/resources_detail.aspx?Page=perfacc.ascx
Applications Vis-à-vis Conductivity Requirements
Metal Yarns
Blend of metal &
textile fibres
Traditional Conductive Textiles
Solution- Conductive Polymers
Metallic coating
Abrasion of m/c parts
Metalized hand
Poor Comfort
Complex Process
Cost
Methods Limitations
Non-homogenous blends
Poly(phenylene-vinylene)
n
n
S
n
n
Polypyrrole
Polythiopene
Polyaniline
Source- G. Wallace and co-workers ,Conductive Electroactive Polymers-CRC press, 20003
Poly(thienylene-vinylene)
Poly(para-phenylene)
Poly(phenylenesulfide)
nN
Poly(pyridine)
NH
Poly(diphenylamine)
Conducting Polymers
Polymerization methods
•Chemical Polymerization
•Electrochemical Polymerization
•Interfacial Polymerization
•Plasma Polymerization
•Copolymerization
Polymerization
• Substrates-
Woven: Cotton, Polyester, Polyester/Cotton blend
Nonwovens: Jute, Polypropylene
• Coating substance- Intrinsic Conductive Polymers (ICP’s)
• Method used: Oxidative in-situ chemical polymerization
Experimental
Indian Patent Filed
Oxidant dispensing
mechanism
Temp. regulating
system Reaction Bath
Monomer
solution
Reaction set- up
BTRA’s method of in-situ chemical Polymerization
Nonwoven PP / Jute fabric
Nonwoven PP / Jute fabric
Monomer Treatment for
I hr
.
Addition of Oxidant at
controlled temp
Addition of Oxidant at
controlled temp
Polymerization for 3hrsWashingWashing
Conducting PP / Jute, samples is
ready
Deposition of ICP’s on Jute & PP Nonwoven
• Electrical Conductivity
• EMI Shielding Properties
• Morphological Studies (SEM Studies)
Characterization
•AATCC Test Method 76-2005
S.R. = Resistance X Width of Electrodes
Distance between electrodes
Unit – ohm/square (Ω/) Where, size of the square is immaterial.
Measurement of Electrical Surface Resistivity
• ASTM-D-257 Test
Concentric ring probe Method
Suitable for samples having resistance in the range of 106
TO 1010
ohms/square.
Measurement of Electrical Surface Resistivity
S.R. = Resistance X 2 πr
Distance between two electrode (cm)
Where,
r = radius of inner concentric ring
ASTM-D-4935-2010
• EMI shielding effectiveness is attenuation of an electromagnetic
wave produced by its passage through shield.
• Expressed as decibel(dB).
• Method used: Coaxial transmission line in frequency range 30 MHz to
1500 MHz
Measurement of EMI Shielding Effectiveness
RESULTS &
DISCUSSION
Surface Resistivity of woven cotton fabric
Pyrrole (%)Surface Resistivity (Ω/)
Polymerization Duration 2 hrs. 3 hrs. 4 hrs.
10 2718 1012 945
20 86 44 33
30 27 17 15
Untreated cotton Pyrrole 10 %
Pyrrole 20 % Pyrrole 30%
Surface Morphology
2 Hours Polymerization
SUBSTRATE MONOMER
DEPOSITED ON 10
GM SUBSTRATE
SURFACE RESISTIVITY
(Ohm/square)
PPY-Coated
Cotton
10 -30% 20 to 2000
PANI- Coated
Cotton
0.1M – 0.3M 1500 - 7000
PPY Coated PC-
Blend
10 – 30 % 50 - 2500
PANI Coated
Polyester
0.1 M 2500
Surface Resistivity of Variable Woven Fabrics
0
20
40
60
80
100
120
140
PP Jute
Su
rfa
ce
Re
sis
tivit
y
(oh
m/s
qu
are
)
Resistivity of Control Nonwoven – 1012 – 1014 ohm/square
Surface Resistivity of Nonwovens
Original PP Original Jute
CP coated PP
Nonwoven
CP coated Jute
Nonwoven
Surface Morphology
CP coated PP
Nonwoven
CP coated Jute
Nonwoven
Cross sectional View
Surface Morphology
0
5
10
15
20
25
PP Jute
EM
I S
E (
dB
)
EMI Shielding Properties of Polymer coated Nonwovens
Sr. No.
Fabric type SurfaceResistivity
(Ω/)
EMI shielding
Grade
1 CP coated Jute
Nonwoven
20 20dB
(30MHz-1.5GHz)
Very Good*
2 CP coated PP
Nonwoven
120 15 dB
(30MHz-1.5 GHz)
Good*
3 CP coated
Woven Cotton
20 30dB
(30MHz-1.5GHz)
Very Good*
CP coated conductive textiles for EMI Shielding
*Suitable for general use:
(Casual wear, office uniform, apron, consumptive electronic products and communication related products.)
Development of Prototypes for specific application:
• Smart textile for occupancy detection (smart mat)
• Smart textile for heat generation (Warming jacket, heating pads)
• Smart textile for Gas Sensing (Ammonia Sensors and Ethanol Sensors)
• Smart textile for Security application
• Smart textile for EMI Shielding.
Indian Patent Filed
Work done at BTRA
•Intruder DetectionHouseholdsCommercial establishmentsSecure areasCarsTheaters
Smart Mat
Smart Textiles
Textiles based SOS systemTextiles based SOS systemTextiles based SOS systemTextiles based SOS system----
Pre-recordedMessage(SOS)
Security ApplicationsSecurity ApplicationsSecurity ApplicationsSecurity Applications
Smart Textiles
Voltage
applied
Increase in current flow,
converted to dissipated heat
Fabric based
heating element
Heat Generation
Up to 45° C
Heating PadsHeating PadsHeating PadsHeating Pads
Thermal BlanketThermal BlanketThermal BlanketThermal Blanket
Heating Pads:• Thermal Therapy – to combat
backaches, muscle & joint pain.
• Reduces sensation by
stimulating thermo receptors.
Electrical thermal
blanket:• High altitude applications.
• Provide warmth and comfort in
cold weather conditions.
• Temperature can be maintained
at 40-450 C.
• Battery operation- 12V, 24V.
Heat Generation
Inclusion of Heating Pads:• Warmth up to 40-42 oC
• Battery operation (12V, 24V)
• Easy handling (detachable)
• Gloves
• Socks
• Shoes
Warmth Providing Jacket
NH3
Cylinder
PPy-cotton
substrate
Gas Detector
Mass flow
controller
mA
Schematic Diagram of Gas detection System
Use of Conductive fabric as Gas Sensors
•Fabric based gas sensors-Polyaniline coated cotton fabrics for ammonia gas sensing
Source- Bhat N.V and co-workers, Textile Research Journal, 2004:74,155
Gas sensing chamber
Gas inlet
Gas outlet
Smart Textiles
* Final stage of acceptance.
Advantages:• Very effective to check the
problem with electrical
activity of patients heart.
•Signal traced are very clear
without using ECG gel.
• No use of metal or any other
corrosive element.
•Very handy and comfortable
to use by patients.
•Disposable and Low in cost.
Fabric based ECG-Electrodes
ICP Coated Textiles : Issues
Advantages
• Tunable conductive textile substrates
• Suitable for most applications
• Ease of Synthesis
• Low cost process
• Retains comfort property
Limitations
• Durability concerns
Measurement of Electrical Surface Resistivity
Four Points probe Resistivity Measurement method
•Voltage drop in the current wires does not contribute error to
the voltage measurement.
•With two probes, the voltage drop from the current flow will not
be separable from the voltage drop in the device under test. It
may be a significant error in low resistance devices.
•Theory used: Vander Paw method.
• Simple polymerization & easy adaptability for large scale.
• Applicable to all kinds of textile substrates.
• Broad range of electrical properties (10 -106 ohm/sqr.) with polymer coatings. Hence useful in variable smart textile applications (pressure sensing, gas sensing) and heat generation applications.
Summary