1st International Conference on Intelligent Autonomous Systems(ICoIAS2018) Yuya Koyama, Michiko Nishiyama, Kazuhiro Watanabe Faculty of science and engineering, Dept. of Information Systems Science, Soka University

1. Smart Textile with Plain Weave
Structure Using Hetero-Core Optical
Fiber Sensor and Wool Threads
Yuya Koyama, Michiko Nishiyama, Kazuhiro Watanabe
Faculty of science and engineering, Dept. of Information
Systems Science, Soka University

2. Contents
1. Introduction
2. Hetero-core optical fiber sensor
3. Smart textile and its sensor performance
4. Hand motion detection test
5. Conclusion

3. Back ground
Smart sensor systems in daily life
 Health care
 Daily activities
Pulse
Respiration
Body movement
Human should be not aware of the sensors
Embedded sensor elements detect
small deformations in the structure
Sensor
Smart textiles The textile senses the deformation in the structure
Fabrics and garments with embedded
electronics and sensors
Clothes, cushions, and
carpets in daily life
applying

4. Hetero-core optical fiber sensor
Hetero-core portion
(1~2mm)
Cladding
125μm
Core 9μmCore5μm
SM Transmission lineSM Transmission line
Core 9μm
Macro-bending can be detected by measuring optical loss
0
1
2
3
4
5
0 2 4Opticalloss[dB]
Displacement [mm]
Hetero-core fiber
Displacement

5. Features and advantages
High sensitivity to macro-bending on sensor portion
No temperature dependency
Low cost monitoring system based on optical intensity
These features are useful to embed the sensor
element into flexible textiles

6. Purpose
Smart textile using hetero-core optical fiber
The plain weave structure for hetero-core optical
fiber woven with a textile
Sensor performances for bend, stretch, and press
Demonstration for hand motion using the smart
textile
Textile structure with conversion from bending to
deformation of textile was investigated

7. Hetero-core portion
Cross-sectional view
Warp thread
Woof thread
(horizontal thread)
Hetero-core
optical fiber
Warp thread
(vertical thread)
Weaving pattern
Hetero-core portion is given macro-
bending by warp thread
Structure
The textile deformation due to small bend, stretch, and
press can be detected by only light intensity changes
Stretch
Bend
Press
Smart textile using hetero-core optical fiber

8. Area with embedded
hetero-core fiber
Hetero-core
portion
Optical fiber
transmission
line
Enlarged view
110 mm
210 mm
Smart textile using hetero-core optical fiber
The hetero-core fiber was successfully woven with wool threads

9. Hetero-core portion
Experimental setup
LED/PD
(λ=1.31 μm)
Optical fiber ine
A/D converter PC
Sampling frequency: 20 Hz
Sensitive textile
Optical loss characteristics for bend, stretch, press were obtained to verify sensor
performance
The transmitted light was coupled to the photodiode and converted to
voltage with an A/D converter to detect the light intensity changes at
the wavelength of 1.31 um
transmitted light

10. Moving
mechanical stage
Textile
Mechanical stage
Initial distance:
70 mm
Clamper
Hetero-core
optical fiber
Hetero-core portion
Stretch characteristics
Full scale: 7mm
Stepwise resolution: 0.35mm
Trials: 20
The textile has the sensitivity depending on stretch from 5 to
10 %
10%
-0.05
0
0.05
0.1
0.15
0.2
0 1 2 3 4 5 6 7Opticalloss[dB]
Displacement [mm]
5%Stretch ratio:
No sensitive area
Sensor area in the
textile

11. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 5 10 15 20
Opticalloss[dB]
Load [N]
Moving
force gauge
0.0N Force gauge
Test stand for
force gauge
Textile
Gauge head
(R=6.5mm)
Press characteristics
The textile has the sensitivity depending on press
Full scale: 20N
Stepwise resolution: 1 N
Trials: 1
Sensor area in the
textile

12. Textile is bent by moving
mechanical stage
Initial distance: 175 mm
Applied
displacement
Hetero-core
optical fiber
Bend characteristics
Full scale: 20mm
Stepwise resolution: 1 mm
Trials: 20
-0.05
0
0.05
0.1
0.15
0.2
0 5 10 15 20
Opticalloss[dB]
Applied displacement [mm]
Center
Right
Left
Sensor area in the
textile
Three sensor areas of textile have the sensitivity against the
bend to the textile
Center area: 0.18dB
Right area: 0.07dB
Left area: 0.04dB
Sensitivity
Multichannel LED/PD device was used for
monitoring 3 optical fiber sensors simultaneously

13. Hand motion detection test
Textile was
rolled around
forearm
Both ends of
textile was
fastened
with a clip
Setup
An application for hand motion monitoring using the
proposed textile was demonstrated
The setup simulates
sleeve in clothes
Releasing gripping
Repeated
motion
Hand motion
Sensor position Muscle
for gripping hand

14. 0
0.2
0.4
0.6
0.8
0 1 2 3 4 5 6 7
Loss[dB]
Time [s]
Sensor position
0.6-0.7dB
Hand motion detection test
The optical loss changed depending
on gripping and releasing
Attributable to press on the textile
The developed textile detected the hand motion
 The sensitivity is so higher
than that of bend and stretch
characteristics
 The textile was fit to the arm

15. Conclusion
Smart textile using hetero-core optical fiber
 Hetero-core optical fiber sensor was woven together
with wool threads
→Smart textile has been fabricated
 Sensor performance for stretch, press, and bend to the textile
→ 0.14 dB for stretch, 1.2 dB for press, and 0.15 dB for bend
 Real-time monitoring has been demonstrated for hand motion
→Hand motion were successfully detected
Smart textile using hetero-core fiber optics is useful to apply for
smart clothes

16. Thank you very much for your attention.