Nanogenerators H ti b d ti f i– Harvesting body motion energy for powering

conventional electronics

Zhong Lin (Z.L.) Wang

S h l f M t i l S i d E i iSchool of Materials Science and EngineeringGeorgia Institute of Technology

Atlanta, GA

Research supported by DARPA, NSF, BES DOE, NIH

www.nanoscience.gatech.edu/zlwang 1

Reality: now and future• More personal electronics• More mobile electronics

More sensors• More sensors• …

• More tiny power sources• More waste• More environmental concerns• …

2www.nanoscience.gatech.edu/zlwang

Motivation: Self-powering, independent and defect tolerated sensor networkdefect tolerated sensor network

Energy in environment

Energy harvester

Applications: • Implantable sensorsEnergy • Implantable sensors • Remote patient monitoring • Environmental monitoring

storage

SensorsData

transmitter & i • Internet of things

• Long range asset tracking • Structural monitoring

Data processor

& controller

& receiver

• Structural monitoring • National security • ….

controller

Changes in environment3www.nanoscience.gatech.edu/zlwang

Objective: harvesting energy from environment (body motion)(body motion)

Table 1. Mechanical energy from typical body motions and the expected electrical energy can be generated.

Activity Mechanical Electrical Electrical energy per movement

How much energy does each of us have?

Irregular energy:- Low frequency;

Activity Mechanical Electrical Electrical energy per movement

Blood flow 0.93W 0.16W 0.16JExhalation 1.00W 0.17W 1.02JBreath 0.83W 0.14W 0.84JLow frequency;

- Variable frequency;- Variable amplitudes

Upper limbs 3.00W 0.51W 2.25JFingers type 6.9-19mW 1.2-3.2mW 226-406μJWalk 67.00W 11.39W 18.9J

4www.nanoscience.gatech.edu/zlwang

Controlled growth of ZnO nanowires

Science 291 (2001) 1947ZnO

ZnO:

• Semiconductor• Piezoelectricity• Optical material

$5/lb

www.nanoscience.gatech.edu/zlwang 5

2 μm

Scientific principle of the nanogenerator

• Convert tiny body motion into electricity using nanomaterials;

• Tolerate variation in driving

I

-

frequencies and amplitudes;

• Build self-powering d i d t

RLVL

+

-ZnO

nanodevices and nanosystems;

• Possible source of energies: biological mechanical energybiological mechanical energy, acoustic/ultrasonic vibration energy, and biofluid hydraulic energy into electricityenergy, into electricity.

Wang & Song, Science, 312 (2006) 242.Wang et al., Nano Letters, 3 (2004) 423-426

6www.nanoscience.gatech.edu/zlwang

F

Fundamental physics: Piezoelectric potential (Piezopotential)

-+ PPiezoelectric effect:

F

cInner potential created by strain;

f fV+V- V-Switch polarity by switch sign in strain;

V-Drive/control charge transport

www.nanoscience.gatech.edu/zlwang

Single wire nanogenerator

10

20400

600

FSFS FSFSo

g g

-20

-10

0

10

olta

ge (m

V)

400

-200

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Cur

rent

(pA

)

FRFR FRFRFRFR FRFR

FSFS FSFS

conn

ectio

n to

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t sys

tem

-600

-400

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Cur

rent

(pA)

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Vol

tage

(mV

)

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0 20 40 60 80 100 120 140-50

-40

-30Vo

Time (Second)0 20 40 60 80 100 120 140

-800

-600

-400

Time (Second)Fo

rwar

d-c

mea

sure

m

25.3 25.5Time (Second)25.2 25.4-50

Time (Second)V+V-

( )

C DA

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ren A C

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Time (Second)

Nature Nanotechnology, 4 (2009) 34-39 www.nanoscience.gatech.edu/zlwang

Electricity generation by finger movementy g y g

20

V)

10

20

olta

ge (m

V)

0

Volta

ge (m

V

39.3 39.6 39.90

Vo

Time (Second)

0 10 20 30 40 50 60 70 80

-20

V

www.nanoscience.gatech.edu/zlwang 9

0 10 20 30 40 50 60 70 80Time (Second) Nano Letters, 9 (2009) 1201

Nanogenerator: engineering scale up and integrationNanogenerator: engineering scale up and integration

Nano Letters, 10 (2010) 315111www.nanoscience.gatech.edu/zlwang

Lighting up an LED by nanogenerator: applications

1.0

06

0.8

(V)

02

0.4

0.6

Volta

ge (

0.0

0.2V

0 5 10 15 20Time (s)

Nano Letters, 10 (2010) 3151

12www.nanoscience.gatech.edu/zlwang

Driving a commercial LCD by nanogenerator

F

x

y z

Hu, Zhang, Xu … Wang, Nano Letts. 13www.nanoscience.gatech.edu/zlwang

Driving a laser diode by nanogenerator

0F

g y g

0

‐0.2

‐0.4V (V)

‐0.6

‐0.8

• Stacked fabrication of NGsof NGs

• Rectification• Charge storage

14www.nanoscience.gatech.edu/zlwang

D t ti “ lf i ”Demonstrating a “self-powering” nanosensor

• Nanogenrator as power source;N ti it

H+ OH-

Nanosensor• Nanosensor as action unit• Integrated system for independent

and self-sufficient operation

Nanogeneratorg

Xu, Qin, Xu … Wang, Nature Nanotech, 5 (2010) 366. 16www.nanoscience.gatech.edu/zlwang

Nanogenerator: from science to engineering and to applications

1. AFM based nanogenerator

2. DC nanogenerator 3. Fiber nanogenerator 4. Lateral and packaged NG

and to applications2005-2008: Science

nanogenerator

RL

I

VL+

-ZnO

Science 316 (2007) 102 Nature Nanotech., 4 (2009) 34

Nature 451 (2008) 809

6. Powering nanodevices5. In-vivo nanogenerator

+

7 Lighting up a LED

Science, 312 (2006) 242.

Science 316 (2007) 102Nano Letters, 8 (2008) 4027

Nature Nanotech., 4 (2009) 34Nano Letters, 9 (2009) 1201

Hybrid cells2009-2010: Engineering 2010-future: applications

6. Powering nanodevices5. In vivo nanogenerator 7. Lighting up a LED y

0.5 cm

Nature Nanotech., 5 (2010) 366Nano Letts., onlineAdv. Mater. 22 (2010) 2534 JACS, 131 (2009) 5866

ACS Nano, 4 (2010) 364717www.nanoscience.gatech.edu/zlwang

Perspectives of NanogeneratorPerspectives of NanogeneratorScience – engineering – technology - commercialization

Blood flow & heart beating

Breath

Wireless sensors

Implantable devices

Wind

sensorsRobots

Mechanical energy sourcesWave

Nanosensors

sourcesWave

Body movements

MEMs

Car running

Air conditioning

movements MP3sCell phones

Laptops

www.nanoscience.gatech.edu/zlwang

g

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