1 Name ： Chien-Liang Mu ( 穆建良 ) Advisor ： Cheng-Hsin Chuang ( 莊承鑫 ) Department of Mechanical Engineering & Institute of Nanotechnology Southern Taiwan

1

Name ： Chien-Liang Mu (穆建良 )

Advisor ： Cheng-Hsin Chuang (莊承鑫 )

Department of Mechanical Engineering & Institute of Nanotechnology Southern Taiwan UniversitySouthern Taiwan University ofof Science and TechnologyScience and Technology, Tainan Taiwan

Date ： 2014-03-19

可感知力量與雙軸滑動運用具結構化電極之軟性複合式觸覺感測器

2

Motivation

The Concept of Multifunction Tactile Sensor

Numerical Simulation

Sensor Fabrication

Experiment Setup and Measurement System

Results and Discussion

Conclusions

OutlineOutline

3

Motivation



Sensor Fabrication



Conclusions

OutlineOutline

MotivationMotivation

The photographer for the manipulations of robotic

•Mechanical property•Surface roughness•Contact position

•Object slippage•Contact force

The controlling conditions of precision grasping:

The mechanical arm for the auxiliary medical application

Industrial automation Militarization

Entertainment services

4

5

Motivation



Sensor Fabrication



Conclusions

OutlineOutline

Mechanism of Slippage SensingMechanism of Slippage Sensing

CompressiveStress

TensileStress

Inner Structure

Shear Force

Normal Force

6

Advantages:•Polymer-based, PVDF

•Simple Structure •Passive Device

•Potential for Large Area

Disadvantages:•Only for Dynamic Force•Relative low Sensitivity

•Cross-talk Effect

Lateral Force:

Friction

Static Force:ObjectWeight

Shear Force

Time[s]

Sens

or O

utpu

t[V]

Time[s]

Sens

or O

utpu

t[V]

Time[s]

Sens

or O

utpu

t[V]

Time[s]

Sens

or O

utpu

t[V]

Electrode

PVDF

Structure

Strain Gauge

Mechanism of Contact Force SensingMechanism of Contact Force Sensing

Time [s]Se

nsor

Out

put

[V

]

7

Advantages:•High sensitivity •Simple Structure

•Small size and lightweight•Cheap

Disadvantages:•Temperature Effect

•Adhesive quality impact •Single direction

measurement

8

Motivation



Sensor Fabrication



Conclusions

OutlineOutline

Numerical Simulation (Uniaxial)Numerical Simulation (Uniaxial)

MaterialsLength (mm)

Width (mm)

Thickness (mm)

Inner Structure 2 2 3

Package Layer (Top) 15 15 4

Package Layer (Bottom) 15 15 1

PVDF Film 4 4 28×10-3

PI Film 9 9 50×10-3

Strain Gauge 4 4 100×10-3

The specifications of tactile sensor

The tactile sensor model design of FEM

Property Units PVDF PI Film Inner Structure Package Strain Gauge

Density kg/m³ 1780 1353 1570 1083 1353

Young’ s modulus MPa 3000 2510 5.45 1 2510

Poisson’s ratio - 0.35 0.34 0.48 0.48 0.34

Dielectric constant Farad/m 11ˣ10-10

d211,d233 m/Volt 23ˣ10-12

d222 m/Volt -33ˣ10-12

Material Properties for Numerical Simulation

Uniform Load of 1N

Package Layer Package Layer (Top)(Top)

Inner StructureInner Structure

Package LayerPackage Layer(Bottom)(Bottom)

PI Film PI Film

Strain GaugeStrain Gauge

PVDF FilmPVDF Film

The sensor size about 15 × 15 × 5 mm3

Shear Force of 1N

9

Numerical SimulationNumerical Simulation-Concept Validation

The contour of stress on the strain gauge surface

Extracted Path

X(1)

Y(2)

Z(3)0 0.001 0.002 0.003 0.004

D ista n ce [m ]

60000

80000

100000

120000

140000

160000

S11

-Str

ess

[Pa]

The profile of electric potential along an extracted path

10

Shear ForceShear Force

PVDF Film

Numerical SimulationNumerical Simulation-Concept Validation

X(1)

Y(2)

Z(3)

The contour of electric potential on the PVDF surface

InnerStructural

Extracted Path

Extracted Path

0 0.001 0.002 0.003 0.004

D ista n ce [m ]

-20000

-10000

0

10000

20000

S22

-Str

ess

[Pa]

0 0.001 0.002 0.003 0.004

D ista n ce [m ]

-0 .15

-0.1

-0.05

0

0.05

0.1

0.15

Ele

ctri

cal P

oten

tial

[V

]

Compressive Stress

Positive Electrical Potential

Tensile Stress

Negative Electrical Potential

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Materials diameter (mm)

Thickness(mm)

Inner Structure (PDMS 160) 2 3

Package Layer (Top) 15 4

Package Layer (Bottom) 15 1

Adhesives (OCA Film) 15 25×10-3

PVDF Film 2 28×10-3

FPC Film (Top) 15 38×10-3

FPC Film (Bottom) 15 38×10-3

PI Film

PVDF Film

Adhesives

Package Layer (Top)

Package Layer (Bottom)

Inner Structure

Numerical Simulation (Biaxial)Numerical Simulation (Biaxial)

CD

接地AB CD

A

B

Shear Load of 1N

Mesh: 183,441 Elements

0˚滑動方向 45˚

90˚

180˚

Numerical Simulation(Numerical Simulation(00 。。 ))Stres

s

Voltage

Shea

r for

ce 1

NSh

ear f

orce

1N

PVDF Film

Tensile Stress


Compressive Stress


Stress

Voltage

Shear f

orce 1N

Shear f

orce 1N

PVDF Film

Tensile Stress


Compressive Stress


Numerical Simulation(Numerical Simulation(4545 。。 ))

Stress

Voltage

Shear force 1N

Shear force 1N

PVDF Film

Tensile Stress


Compressive Stress



Stress

Voltage

Shear force 1NShear force 1N

PVDF Film

Tensile Stress


Compressive Stress



17

Motivation



Sensor Fabrication



Conclusions

OutlineOutline

SensorSensor Fabrication Fabrication

(ii) Coat PR →Exposure →Develop

(iii) Wet etching electrode

(iv) Strip PR

(i) FPC thin film

(v) PVDF thin film

(vi) Strip Ag layer on PVDF thin film surface

(vii) Bonding by adhesive

(viii) PMMA master by machining

(ix) Inner structure molding by silicone rubber

(x) Bonding silicone rubber structure upon electrodes

(xi) Package with PDMS

(vii) Bonding Strain gauge by M-BOND 200 adhesive

Silicone rubber

Mask

Ag

PRCu PI

PDMS PMMAPVDF

Adhesion layer Strain Gauge

FPC Film

MicroelectrodePVDF Film

OCA

Strain GaugeInner Structure

PDMS

Photograph of flexible tactile sensorwith structural electrode 18

Bottom ElectrodeTop Electrode

Bottom ElectrodeTop Electrode

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Motivation



Sensor Fabrication



Conclusions

OutlineOutline

20

ConclusionsConclusions

• 電極圖案、結構大小更改，是否有效改善滑動訊號於量測上準確度。

• 裝置於機器手臂上，觀察夾取力量與初始滑動產生

Thank you for your attention

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Documents

1 Name ： Chien-Liang Mu ( 穆建良 ) Advisor ： Cheng-Hsin Chuang ( 莊承鑫 ) Department of Mechanical Engineering & Institute of Nanotechnology Southern Taiwan