The effect of strain and frequency on the

harvested energy of an electrostrictive

polymer composite

Miss Kavalin Raya

ID 5510210555

Department of physics Prince of Songkla university

P105, 12th October 2015, 1.00-3.30 P.M.

1

OUTLINE

• Introduction1.

•Experimentation2.

•Result & Discussion3.

•Conclusions4.

2

Energy harvesting

Energy harvesting is the process by which energy is capture and

stored , also reference to as “energy scavenging” or “energy

extraction” can be defined as converting ambient energies such

wind , vibrations ,light etc.

To usable electrical energy by using energy conversion materials or

subsequent storage of the electrical energy for powering electrical

device.

3

Comparison energy sourcesPower density( μ𝑾 𝒄𝒎𝟐)

1 year lifetimePower density( μ𝑾 𝒄𝒎𝟐)

10 year lifetime

Solar cell 15,000 direct sun150 (cloudy day)

15,000 direct sun*150 (cloudy day)

Vibrations 200 200*

*Roundy et al.,2003

4

Vibration Energy harvesting

• Harvesting energy smart material

oPiezoelectric harvesting energy

oElectrostrictive harvesting energy

• Harvesting energy smart material

o Electromagnetic

o electrostatic

5

Polymers for Energy harvesting

advantage disadvantage

• No external voltage source

• High voltage of 2~10V

• Compatible with MEMS

• Depolarization and aging

problems

• Brittleness

• Charge leakage

• High output impedance

Piezoelectric polymer harvesting energy

Electrostrictive polymer harvesting energy

• Flexibility and high electromechanical response

6

Energy conversion using Electrostrictive polymer ?

ESP

Energy(electrical)

generate

actuator

Mechanical workE W

Electrostrictive polymer convert electrical energy to

mechanical work and vice versa.

7

The purpose of this paper is a study of a effect of

strain amplitude and operating frequency on the harvested

current of the electrostrictive polymer composite.

8

Theoretical

𝑆1 = 𝑀31𝐸32 + 𝑠11𝑇1

𝐷3 = Ԑ33𝐸3 + 2𝑀31𝐸3𝑇1

𝐷3 = Ԑ33𝐸3 +2𝑀31

𝑆11𝐸3𝑆1 − 2

𝑀312 𝐸3

3

𝑆11

Electrostrictiveeffects

Electric displacement

3

2

1

𝑺𝟏 the strain

𝑴𝟑𝟏 the electrostriction coefficient

𝒔𝟏𝟏 the elastic compliance

𝑻𝟏 The stress

𝑫𝟑 the electric displacement

Ԑ𝟑𝟑 the linear dielectric permittivity

9

𝐼 =

𝐴

𝜕𝐷3𝜕𝑡𝑑𝐴

𝐼 = 𝐴𝜕𝐸3

𝜕𝑡Ԑ33𝑇 +

2𝑀31𝑆1−6𝑀312 𝐸3

2

𝑆11𝐸 +

2𝑀31𝜕𝑆1𝜕𝑡𝐸3

𝑆11𝐸 𝑑𝐴

Applied DC electric field on the sample (𝐸𝐷𝐶) so 𝜕E3

𝜕t= 0

𝐼 = 2𝑀31∗ 𝑌EDC 𝐴

𝜕𝑆1

𝜕𝑡𝑑𝐴

𝑃 = 𝑅𝐼𝑟𝑚𝑠2

when

𝐼 is the current induced by set-up vibration

𝐸𝐷𝐶 is the electric field

𝑃 is the harvested power

10

Experimentation o Film preparation

o Energy conversion with electrostrictive polymer

11

Film preparation

PU

80°

C

45min

DMFCarbon

nanopowders

80°

C

12 min

DMF

60°C 12hr

80°C 6hr

Ultrasonic

80°

C ,20min

Nonocomposite solution

Spin-coating

55 × 22 𝑚𝑚2 , 60μ𝑚12

set-up energy harvesting

http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6253823

Various Conditions• Strain amplitude of 0.75,2,4,and 6.5%• Frequency 3,6,and 9 Hz• Sample thickness 60μm

sample

resistor

Vbias

13

Fig.1. The strain and strength function of time.

Condition

• Strain amplitude of 0.75,2,4,and 6.5%

• Frequency 3,6,and 9 Hz

• Sample thickness 60μm

sample

resistor

Vbias

14

Results and discussions

Fig.2. The current as a function of transverse strain for a static electric

field of 13 V/μm and two mechanical frequency (i.e., 3 Hz and 6 Hz).

Current is almost double if they

double the frequency of

mechanical of excitation.

15

Fig.3. The current as a function of frequency for field of 13 V/μm,

two amplitude of strain (i.e., 2 and 6.5%).

When these strain and frequency

increases, the current increases

proportional.

16

Table 1

The electrical efficiency as a function of mechanical frequency for a constant strain of

5% and static field 13V/μm.

Table 2

The electrical efficiency as a function of transverse strain in for a mechanical

frequency of 6 Hz and static field 13V/μm.

Frequency (Hz) 3 6 9

Electrical Efficiency (%) 37.14 52.32 62.34

Strain (%) 0.75 2 4 6.5

Electrical Efficiency (%) 33.3 37.6 50.6 53.3

17

Conclusions

• Accoring to the experimental result ,the polyurethane samples were

prepared using solution casting method which all films has a rectangular

(55 ×20mm𝟐

) .

• The electrical efficiency becomes positive (51%) with a transverse strain

amplitude of 4% at 6 Hz for the electric field of 13 V/μm.

• The harvested current of electrostrictive films increases when the

frequency and the amplitude of mechanical strain were increased.

18

References

Mounir Medded, Adil Eddiai, Abdelowahed Hajaji, Yahia Boughaleb, Daniel

Guyomar, Mohamed Filyou, Synthetic Metals,188, 72– 76, 2014.

Adil Eddiai, Mounir Meddad , Khalid Sbiaai, Yahia Boughaleb,

Abdelowahed Hajjaji, Daniel Guyomar, Optical Materials ,36 ,13–17, 2014

Chatchai Putson,Energy convertion from electroactive materials and

Modeling of behaviour on these materialss,2010

19

Acknowledgement

Asst Prof Dr.Chatchai Putson

Committee of Physics seminar

Department of Physics, Prince of Songkla University

Friends and family

20

21

22

Summary of the comparison of the different type of mechanism

type advantage disadvantage

piezoelectric • No external valtage source• High voltage of 2~10V• Compact configuration• Compatible with MEMS

• Depolarization and aging problems

• Brittness• Charge leakage• High output impedance

electrostrictive • Compatible with MEMS• high electromechanical

response• flixibility

23

The electrical efficiency of the polymer calculated by the ratio between the

input power and that harvested increases with transverse strain by the

increasing of mechanical frequency.

24