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transcript
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 17
journal homepage wwwelseviercomlocatenanoenergy
Available online at wwwsciencedirectcom
RAPID COMMUNICATION
Two-dimensional rotary triboelectric
nanogenerator as a portable and wearable
power source for electronics
Shuang Yang Kuanga Jun Chenb Xiao Bei Chenga Guang Zhuan
Zhong Lin Wangab
aBeijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 100083 ChinabSchool of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332 USA
Received 14 May 2015 received in revised form 17 June 2015 accepted 9 July 2015
Available online 5 August 2015
KEYWORDSEnergy harvestingTriboelectric nano-
generatorSelf-poweredWearable electronics
Abstract
Harvesting energy from ambient mechanical motions addresses limitations of traditional power
supplies by providing a sustained electric power source Here a high-performance rotary
triboelectric nanogenerator (r-TENG) is applied in a variety of circumstances to speci1047297callyharvest mechanical energy from human body motions When rotating at 500 r min1 it can
produce an ac electric output that has a current amplitude of 075 mA and a voltage amplitude
of 200 V at a frequency of 750 Hz Integrated with structural components that transfer
mechanical motions and electric components that achieve power management the r-TENG is
demonstrated as a power source by harvesting energy from foot pedaling arm swinging and
foot pressure The generated electricity can effectively charge consumer electronics such as a
cellphone which shows the promise of the r-TENG as a power source for portable wearable
and even implantable electronics
amp 2015 Elsevier Ltd All rights reserved
Introduction
The fast development of portable electronics requires a stand-
alone maintenance-free and sustainable power source
Harvesting and converting ambient energy provides a feasible
solution for this purpose Mechanical motion is an attractive
target for energy harvesting due to its great abundance and
ubiquitousness [1ndash6] Current mechanical energy harvesting
technologies are mainly relying on mechanisms including
electromagnetic effect piezoelectric effect and electrostatic
induction [17ndash9] However major challenges are still to be
addressed including low output power structure complexity
httpdxdoiorg101016jnanoen201507011
2211-2855amp 2015 Elsevier Ltd All rights reserved
nCorresponding author
E-mail address zhuguangbinncascn (G Zhu)
Nano Energy (2015) 17 10ndash16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 27
and dif 1047297culty in miniaturization [10ndash16] In recent years
triboelectric nanogenerators (TENG) that had a novel mechan-
ism were developed It is especially suitable as a portable
power source that harvests energy from body motions due to
its prominent advantages of high power density in terms of
power per volume as well as power per weight [11718]
Although various structures of TENGs have been developed
[1719ndash23] high-performance TENGs that are speci1047297cally
designed for harvesting energy from body motions and can
provide useful amount of output power were rarely reported
Here we report a series of solutions for practically poweringand charging portable electronics by harvesting energy from
body motions including foot pedaling hand swinging and foot
pressure These approaches are all based on high-performance
two-dimensional rotary TENGs (r-TENG) Enabled by a design of
two radial-arrayed 1047297ne electrodes that are complementary on
the same plane the planar-structured r-TENG produces peri-
odically changing triboelectric potential that induces alternat-
ing currents between electrodes At a rotating rate of
500 r min1 it can deliver a continuous ac output that has a
short-circuit current of 075 mA in amplitude and an open-
circuit voltage of 200 V at a frequency of 750 Hz By integrating
the r-TENG with other mechanical components it can effec-
tively utilize motions from different parts of human body When
installed onto a bicycle the r-TENG can convert mechanical
energy of foot pedaling into electricity powering an array of
small electronics as well as charging a cellphone Besides it can
harness energy from arm swinging as well as foot pressing
during normal walking Through a power management circuit
the electric output can be used to charge capacitors and
batteries unambiguously demonstrating the r-TENG as a pro-
mising power source for portable wearable and even poten-
tially implantable electronics
Results and discussions
A r-TENG is composed of mainly two parts a stator and a
rotator as depicted in Figure 1a The rotator is a collection
of 90 radially-arrayed sectors made of copper For the
stator it is composed of mainly three parts a layer of
polymethyl methacrylate (PMMA) as a substrate a layer of
electrodes and a layer of polytetra1047298uoroethylene (PTFE) as
an electri1047297cation layer The electrode layer is composed of
electrode A and electrode B which have complementary
patterns separated by 1047297ne gaps in between as shown in the
zoom-in sketches of the inner and outer sections of the
stator in Figure 1a As photographed in Figure 1b and c both
Figure 1 Structural design and working principle of the r-TENG (a) Schematic sketches of the r-TENG (b c) Photographs of a rotatorand a stator (scale bar 3 cm) (d) Charge distribution on open-circuit condition (e) Charge distribution on short-circuit condition
11Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 37
the rotator and the stator have a two-dimensional planar
structure resulting in small volume of the r-TENG The
detailed fabrication process was previously reported
[1724]
The electricity generation of the r-TENG relies on relative
rotation between the rotator and the stator Cycled change
of electric potential due to the motion of triboelectric
charges gives rise to alternating 1047298ows of electrons between
Figure 2 Electric output of a r-TENG that is 120 mm in diameter (a) Short-circuit current and (b) open-circuit voltage of the
r-TENG (c) Output current after transformation (d) Output voltage after transformation All the results are measured at a constant
rotation rate of 500 r min1
Figure 3 Demonstration of the r-TENG in harvesting energy from pedaling a bicycle (a) Transformed short-circuit current at a rotation
rate of 190 r min1 (b) Transformed open-circuit voltage at a rotation rate of 190 r min1 (c) Photograph showing 60 LEDs are being
lighted up simutanously when the bicyle is being pedaled (scale bar 8 cm) (d) Charging current and (e) charging voltage on the battery of
a cellphone (f) Photograph showing a cellphone is being charged when the bicycle is being pedaled (scale bar 8 cm)
SY Kuang et al12
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 47
electrodes The electricity generation process from a single
sector unit is depicted in Figure 1d and e Here two-
dimensional schematic illustrations of the charge distribu-
tion are used for interpretation To begin with when the
rotator rotates coaxially against the stator charge transfer
takes place at the contact interface Negative triboelectric
charges are produced on the PTFE surface since it has a
much stronger tendency to be negatively charged
(Figure 1d) On the open-circuit condition electrons cannot
transfer between electrodes The open-circuit voltage is
then essentially the electric potential difference between
the two electrodes At the initial state when the copper-
made stator is aligned with the left electrode (Figure 1d)
the electric potential of the left and right electrodes is
maximized and minimized respectively which corresponds
to a maximum electric potential difference between the
electrodes When the rotator starts to spin such a potential
difference will diminish to zero when the rotator reaches
the middle point Further rotation will result in a reversely
built-up electric potential difference between the electro-
des as illustrated in the Figure 1d If the two electrodes are
electrically connected namely on the short-circuit condi-tion the induced free electrons can 1047298ow between the
electrodes due to electrostatic induction As the rotator
starts to spin free electrons will keep 1047298owing from the left
electrode to the right electrode until the rotator is in
alignment with the right electrode (Figure 1e) Further
rotation will then generate a current in the opposite
direction
To characterize the electric output of the r-TENG a
programmable motor was employed to provide a mechanical
rotation source at a controlled rate At a rotating rate of
500 r min1 the short-circuit current (Isc) of the r-TENG has
a continuous ac manner at an amplitude of 075 mA and a
frequency of 750 Hz The open-circuit voltage (V oc) exhibits
a peak-to-peak value of 400 V at the same frequency In
order to realize impedance match between the TENG that
has high output impedance and conventional electronics
that are known for low input impedance we transformed
the electric output to enhance the output current at the
expense of the output voltage As shown in Figure 2c and d
the current amplitude is greatly boosted to about 16 mA
while the output voltage drops to about 32 V By doing so
the impedance match ensures that the maximum amount of
electric output can be extracted from the TENG for
practical use
To demonstrate practical applications we designed and
fabricated three types of devices that are based on the r-
TENG First we installed a r-TENG that is 150 mm in
diameter on the wheel axis of a 1047297tness bicycle When being
pedaled the relative rotation between the rotator and the
stator generates high-level electric output As shown in the
Figure 3a and b at a rotation rate of about 183 r min1 the
current amplitude after being tuned by transformers
reaches as high as 13 mA and the voltage amplitude
exceeds 36 V When directly using the generated electricitywe could simultaneously power over 20 LED lamps (12 V
06 W for each) which is demonstrated in Figure 3c and
Supplementary Movie S1 Besides powering small electro-
nics the electric output could be used to charge electro-
nics Here besides transformers we added recti1047297ers
capacitors and voltage regulators to construct a power
management circuit that can provide an output voltage at
a preset value (diagramed in Supplementary Figure S1)
When being plugged into a cellphone a charging system
consisting of the r-TENG and the power management circuit
can effectively charge a battery When being triggered by
pedaling the charging current shoots to 13 mA (Figure 3d)
Figure 4 Demonstration of the r-TENG for harvesting energy from human arm swinging (a) Schematic of the entire device (b) Diagram
of the device when the arm is stretched (c) Diagram of the device when the arm is bent (d) Short-circuit current and (e) open-circuitvoltage of the r-TENG at a swing frequency of 5 Hz (f) Transformed and recti1047297ed current On the right is an enlarged view of the current
signal (g) Photograph showing about 60 LEDs being lighted up simutaneously when the r-TENG is being swung (scale bar 10 cm)
(h) Charging curve of a capacitor with a capacitance of 4700 μF Inset is the diagram of a power management circuit
13Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 57
and the charging voltage 1047298uctuates around 7 V (Figure 3e)
The charging sign was immediately displayed on the cell-
phone screen as shown in Figure 3f and Supplementary
Movie S2
Supplementary material related to this article can be
found online at doi101016jnanoen201507011Second a wearable device for harvesting energy from
human body motion was demonstrated As shown in
Figure 4a the entire device mainly consists of three parts
a base a teethed rack and a r-TENG that is 10 mm in
diameter The r-TENG is attached to the upper arm while
the base is 1047297xed to the front arm around the wrist When
the arm is being swung a rotary torque is generated and
transferred to the r-TENG through the teethed rack and a
gear (Figure 4b and c) As a result the rotator is driven At a
swinging frequency of around 3 Hz the measured Isc(Figure 4d) and the V oc (Figure 4e) have amplitudes of up
to 025 mA and 120 V respectively For a single swinging
motion the instantaneous rotation rate varies and reaches
its peak value midway through the swinging Consequently
the obtained current pack in Figure 3f has the largest
amplitude in the middle However the voltage amplitude
in Figure 4e remains stable since it is velocity-independent
After being recti1047297ed and transformed the output currentbecomes unidirectional and reaches a peak value of 16 mA
The 1047298uctuating dc output in Figure 4g could not only
directly power a LED array (Figure 4h and Supplementary
Movie S3) but also charge a capacitor to have the energy
stored
Furthermore we speci1047297cally designed a device for har-
vesting energy from the foot pressure during normal walk-
ing The entire device is displayed in Figure 5 It has a
dimension of 6 cm by 6 cm by 3 cm Within in the device
two r-TENGs are stacked together in the vertical direction
As sketched in Figure 5b the two rotators share the same
substrate and rotate simultaneously The rotation is
Figure 5 Demonstration of the r-TENG for harvesting energy from foot pressure (a) Photograph of the entire device (b) Sketch
that illustrates the motions transmission component It transforms linear motion to rotation (c) Photograph showing an enlarged
view of the helical axis (d) Photograph showing an enlarged view of two r-TENGs that are stacked together (e) Transformed voltage
of the upper unit r-TENG On the right is an enlarged view of output voltage signal (f) Transformed voltage of the lower unit r-TENG
at a uniform walking rate On the right is an enlarged view of output voltage signal (g) Transformed and recti1047297ed current from the
two r-TENGs On the right is an enlarged view of output current signal (h) Charging curve of a battery with a capacity of 7 mA h
Inset is the corresponding diagram of a charging circuit
SY Kuang et al14
7232019 Two-dimensional Rotary Triboelectric
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triggered by a helical axis in the vertical direction
(Figure 5c) When the helical axis is pressed down it exerts
a rotation torque to the rotator in the clockwise direction
due to its helical structure As a result the liner motion of
the axis is transformed to lateral rotation of the r-TENG It
was found that our design could enable a quarter of circular
rotation provided with a linear motion of 6 mm After
electric transformation the measured output voltage from
the upper r-TENG is shown in Figure 5e There are two
voltage packs in a one cycle This is because rotation in the
counterclockwise direction occurs after the pressing force is
withdrawn because the four springs in the device (Figure 5a)
provides a restoring force It is also noticed that the
releasing process corresponds to higher electric output from
the upper unit which is attributed to the damping effect of
a soft cushion-like structure in the device In contrast the
transformed output voltage from the lower unit exhibits
higher amplitude for the pressing process After further
recti1047297cation and integration the combined output current
from the two r-TENGs has comparable amplitudes for both
pressing and releasing processes as shown in Figure 5g The
amplitude reaches around 5 mA which could charge alithium ion battery of 6 mA h in capacity from 25 V to
32 V in 10 min when the energy-harvesting device is
triggered at a frequency of 1 Hz
Compare with conventional magnetic generators that also
convert rotational motion into electricity the most promi-
nent advantage of the r-TENG is the high power density
Since the r-TENG relies on triboelectric effect at the
surface it requires very little amount of thin-1047297lm materials
Besides the materials used can be low-density polymers As
a result the r-TENG has exceptionally light weight and
small volume making is particularly suitable as an on-body
power source for portablewearable electronics
Conclusions
To summarize we reported a two-dimensional rotary TENG
Enabled by a design of two radial-arrayed 1047297ne electrodes
that are complementary patterns on the same plane the
planar-structured r-TENG can produce periodically changing
triboelectric potential that induces alternating currents
between electrodes Short-circuit current of 075 mA in
amplitude as well as voltage amplitude of 200 V was
generated at a rotating rate of 500 r min1 The unique
structural design enables various applications First the r-
TENG was 1047297rstly installed onto a bike to harvest energy from
pedaling The generated electricity can be used to charge a
cellphone Second the r-TENG can also be harnessed toharvest energy from arm swinging as well as foot pressure
during walking Through a power management circuit the
transformed output can be used to charge portable electro-
nics which unambiguously demonstrates the TENG as a
sustained power source for small electronics
Acknowledgment
The research was supported by the ldquoThousands Talentsrdquo
Program for Pioneer Researcher and His Innovation Team
China Patents have been 1047297led based on the research
presented here
Appendix A Supplementary Information
Supplementary data associated with this article can be found
in the online version at doi101016jnanoen201507011
References
[1] ZL Wang ACS Nano 7 (2013) 9533[2] X Wang J Song J Liu ZL Wang Science 316 (2007) 102
[3] SP Beeby MJ Tudor NM White Meas Sci Technol 17
(2006) 175
[4] J Scruggs P Jacob Science 323 (2009) 1176
[5] R Henderson Renew Energy 31 (2006) 271
[6] AD Kuo Science 309 (2005) 1686
[7] ZL Wang J Song Science 312 (2006) 242
[8] G Zhu B Peng J Chen Q Jing ZL Wang Nano Energy 14
(2015) 126
[9] ZL Wang J Chen L Lin Energy Environ Sci 8 (2015) 2250
[10] VA Jouanne Mech Eng Mag 128 (2006) 24
[11] S Kwon J Park WK Kim Y Yang E Lee CJ Han SY Park
J Lee YS Kim Energy Environ Sci 7 (2014) 3279
[12] W Huang G Wang F Gao Z Qiao G Wang M Chen
Y Deng L Tao Y Zhao X Fan L Sun J Phys Chem C 118(2014) 8783
[13] T Krupenkin JA Taylor Nat Commun 2 (2011) 448
[14] R Henderson Renew Energy 31 (2006) 271
[15] A Wolfbrandt IEEE Trans Magn 42 (2006) 1812
[16] Z Pi J Zhang C Wen ZB Zhang D Wu Nano Energy 7
(2014) 33
[17] G Zhu J Chen Q Jing T Zhang ZL Wang Nat Commun 5
(2014) 3426
[18] G Zhu Y Zhou P Bai X Meng Q Jing J Chen ZL Wang
Adv Mater 26 (2014) 3788
[19] J Chen J Yang Z Li X Fan Y Zi Q Jing H Guo Z Wen
KC Pradel S Niu ZL Wang ACS Nano 9 (2015) 3324
[20] X Meng G Zhu ZL Wang ACS Appl Mater Interfaces 6
(2014) 8011
[21] J Chen G Zhu J Yang Q Jing P Bai W Yang X Qi Y SuZL Wang ACS Nano 9 (2015) 105
[22] W Seung MK Gupta KY Lee KS Shin JH Lee TY Kim
S Kim J Lin JH Kim SW Kim ACS Nano 9 (2015) 3501
[23] J Chen G Zhu W Yang Q Jing P Bai Y Yang TC Hou Z
L Wang Adv Mater 25 (2013) 6094
[24] C Han C Zhang W Tang X Li ZL Wang Nano Res 8 (2014)
722
Shuang Yang Kuang received his bachelors
degree in Physics in Shandong University
Now he is pursuing his masterrsquos degree in
Beijing Institute of Nanoenergy and Nano-
system Chinese Academy of Science His
current research mainly focuses on applica-
tion and fabrication of triboelectricnanogenerators
Jun Chen received hisBSandMSin Elec-
trical Engineeringfromthe School of Electro-
nic Information and Communications at
HuazhongUniversity of Science and Technol-
ogy in2007 and2010 respectively and a
second MS in Biological Engineering from
the College of Engineering at The University
of Georgia in 2012 HeiscurrentlyaPhD
candidate
15Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 27
and dif 1047297culty in miniaturization [10ndash16] In recent years
triboelectric nanogenerators (TENG) that had a novel mechan-
ism were developed It is especially suitable as a portable
power source that harvests energy from body motions due to
its prominent advantages of high power density in terms of
power per volume as well as power per weight [11718]
Although various structures of TENGs have been developed
[1719ndash23] high-performance TENGs that are speci1047297cally
designed for harvesting energy from body motions and can
provide useful amount of output power were rarely reported
Here we report a series of solutions for practically poweringand charging portable electronics by harvesting energy from
body motions including foot pedaling hand swinging and foot
pressure These approaches are all based on high-performance
two-dimensional rotary TENGs (r-TENG) Enabled by a design of
two radial-arrayed 1047297ne electrodes that are complementary on
the same plane the planar-structured r-TENG produces peri-
odically changing triboelectric potential that induces alternat-
ing currents between electrodes At a rotating rate of
500 r min1 it can deliver a continuous ac output that has a
short-circuit current of 075 mA in amplitude and an open-
circuit voltage of 200 V at a frequency of 750 Hz By integrating
the r-TENG with other mechanical components it can effec-
tively utilize motions from different parts of human body When
installed onto a bicycle the r-TENG can convert mechanical
energy of foot pedaling into electricity powering an array of
small electronics as well as charging a cellphone Besides it can
harness energy from arm swinging as well as foot pressing
during normal walking Through a power management circuit
the electric output can be used to charge capacitors and
batteries unambiguously demonstrating the r-TENG as a pro-
mising power source for portable wearable and even poten-
tially implantable electronics
Results and discussions
A r-TENG is composed of mainly two parts a stator and a
rotator as depicted in Figure 1a The rotator is a collection
of 90 radially-arrayed sectors made of copper For the
stator it is composed of mainly three parts a layer of
polymethyl methacrylate (PMMA) as a substrate a layer of
electrodes and a layer of polytetra1047298uoroethylene (PTFE) as
an electri1047297cation layer The electrode layer is composed of
electrode A and electrode B which have complementary
patterns separated by 1047297ne gaps in between as shown in the
zoom-in sketches of the inner and outer sections of the
stator in Figure 1a As photographed in Figure 1b and c both
Figure 1 Structural design and working principle of the r-TENG (a) Schematic sketches of the r-TENG (b c) Photographs of a rotatorand a stator (scale bar 3 cm) (d) Charge distribution on open-circuit condition (e) Charge distribution on short-circuit condition
11Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 37
the rotator and the stator have a two-dimensional planar
structure resulting in small volume of the r-TENG The
detailed fabrication process was previously reported
[1724]
The electricity generation of the r-TENG relies on relative
rotation between the rotator and the stator Cycled change
of electric potential due to the motion of triboelectric
charges gives rise to alternating 1047298ows of electrons between
Figure 2 Electric output of a r-TENG that is 120 mm in diameter (a) Short-circuit current and (b) open-circuit voltage of the
r-TENG (c) Output current after transformation (d) Output voltage after transformation All the results are measured at a constant
rotation rate of 500 r min1
Figure 3 Demonstration of the r-TENG in harvesting energy from pedaling a bicycle (a) Transformed short-circuit current at a rotation
rate of 190 r min1 (b) Transformed open-circuit voltage at a rotation rate of 190 r min1 (c) Photograph showing 60 LEDs are being
lighted up simutanously when the bicyle is being pedaled (scale bar 8 cm) (d) Charging current and (e) charging voltage on the battery of
a cellphone (f) Photograph showing a cellphone is being charged when the bicycle is being pedaled (scale bar 8 cm)
SY Kuang et al12
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 47
electrodes The electricity generation process from a single
sector unit is depicted in Figure 1d and e Here two-
dimensional schematic illustrations of the charge distribu-
tion are used for interpretation To begin with when the
rotator rotates coaxially against the stator charge transfer
takes place at the contact interface Negative triboelectric
charges are produced on the PTFE surface since it has a
much stronger tendency to be negatively charged
(Figure 1d) On the open-circuit condition electrons cannot
transfer between electrodes The open-circuit voltage is
then essentially the electric potential difference between
the two electrodes At the initial state when the copper-
made stator is aligned with the left electrode (Figure 1d)
the electric potential of the left and right electrodes is
maximized and minimized respectively which corresponds
to a maximum electric potential difference between the
electrodes When the rotator starts to spin such a potential
difference will diminish to zero when the rotator reaches
the middle point Further rotation will result in a reversely
built-up electric potential difference between the electro-
des as illustrated in the Figure 1d If the two electrodes are
electrically connected namely on the short-circuit condi-tion the induced free electrons can 1047298ow between the
electrodes due to electrostatic induction As the rotator
starts to spin free electrons will keep 1047298owing from the left
electrode to the right electrode until the rotator is in
alignment with the right electrode (Figure 1e) Further
rotation will then generate a current in the opposite
direction
To characterize the electric output of the r-TENG a
programmable motor was employed to provide a mechanical
rotation source at a controlled rate At a rotating rate of
500 r min1 the short-circuit current (Isc) of the r-TENG has
a continuous ac manner at an amplitude of 075 mA and a
frequency of 750 Hz The open-circuit voltage (V oc) exhibits
a peak-to-peak value of 400 V at the same frequency In
order to realize impedance match between the TENG that
has high output impedance and conventional electronics
that are known for low input impedance we transformed
the electric output to enhance the output current at the
expense of the output voltage As shown in Figure 2c and d
the current amplitude is greatly boosted to about 16 mA
while the output voltage drops to about 32 V By doing so
the impedance match ensures that the maximum amount of
electric output can be extracted from the TENG for
practical use
To demonstrate practical applications we designed and
fabricated three types of devices that are based on the r-
TENG First we installed a r-TENG that is 150 mm in
diameter on the wheel axis of a 1047297tness bicycle When being
pedaled the relative rotation between the rotator and the
stator generates high-level electric output As shown in the
Figure 3a and b at a rotation rate of about 183 r min1 the
current amplitude after being tuned by transformers
reaches as high as 13 mA and the voltage amplitude
exceeds 36 V When directly using the generated electricitywe could simultaneously power over 20 LED lamps (12 V
06 W for each) which is demonstrated in Figure 3c and
Supplementary Movie S1 Besides powering small electro-
nics the electric output could be used to charge electro-
nics Here besides transformers we added recti1047297ers
capacitors and voltage regulators to construct a power
management circuit that can provide an output voltage at
a preset value (diagramed in Supplementary Figure S1)
When being plugged into a cellphone a charging system
consisting of the r-TENG and the power management circuit
can effectively charge a battery When being triggered by
pedaling the charging current shoots to 13 mA (Figure 3d)
Figure 4 Demonstration of the r-TENG for harvesting energy from human arm swinging (a) Schematic of the entire device (b) Diagram
of the device when the arm is stretched (c) Diagram of the device when the arm is bent (d) Short-circuit current and (e) open-circuitvoltage of the r-TENG at a swing frequency of 5 Hz (f) Transformed and recti1047297ed current On the right is an enlarged view of the current
signal (g) Photograph showing about 60 LEDs being lighted up simutaneously when the r-TENG is being swung (scale bar 10 cm)
(h) Charging curve of a capacitor with a capacitance of 4700 μF Inset is the diagram of a power management circuit
13Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 57
and the charging voltage 1047298uctuates around 7 V (Figure 3e)
The charging sign was immediately displayed on the cell-
phone screen as shown in Figure 3f and Supplementary
Movie S2
Supplementary material related to this article can be
found online at doi101016jnanoen201507011Second a wearable device for harvesting energy from
human body motion was demonstrated As shown in
Figure 4a the entire device mainly consists of three parts
a base a teethed rack and a r-TENG that is 10 mm in
diameter The r-TENG is attached to the upper arm while
the base is 1047297xed to the front arm around the wrist When
the arm is being swung a rotary torque is generated and
transferred to the r-TENG through the teethed rack and a
gear (Figure 4b and c) As a result the rotator is driven At a
swinging frequency of around 3 Hz the measured Isc(Figure 4d) and the V oc (Figure 4e) have amplitudes of up
to 025 mA and 120 V respectively For a single swinging
motion the instantaneous rotation rate varies and reaches
its peak value midway through the swinging Consequently
the obtained current pack in Figure 3f has the largest
amplitude in the middle However the voltage amplitude
in Figure 4e remains stable since it is velocity-independent
After being recti1047297ed and transformed the output currentbecomes unidirectional and reaches a peak value of 16 mA
The 1047298uctuating dc output in Figure 4g could not only
directly power a LED array (Figure 4h and Supplementary
Movie S3) but also charge a capacitor to have the energy
stored
Furthermore we speci1047297cally designed a device for har-
vesting energy from the foot pressure during normal walk-
ing The entire device is displayed in Figure 5 It has a
dimension of 6 cm by 6 cm by 3 cm Within in the device
two r-TENGs are stacked together in the vertical direction
As sketched in Figure 5b the two rotators share the same
substrate and rotate simultaneously The rotation is
Figure 5 Demonstration of the r-TENG for harvesting energy from foot pressure (a) Photograph of the entire device (b) Sketch
that illustrates the motions transmission component It transforms linear motion to rotation (c) Photograph showing an enlarged
view of the helical axis (d) Photograph showing an enlarged view of two r-TENGs that are stacked together (e) Transformed voltage
of the upper unit r-TENG On the right is an enlarged view of output voltage signal (f) Transformed voltage of the lower unit r-TENG
at a uniform walking rate On the right is an enlarged view of output voltage signal (g) Transformed and recti1047297ed current from the
two r-TENGs On the right is an enlarged view of output current signal (h) Charging curve of a battery with a capacity of 7 mA h
Inset is the corresponding diagram of a charging circuit
SY Kuang et al14
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 67
triggered by a helical axis in the vertical direction
(Figure 5c) When the helical axis is pressed down it exerts
a rotation torque to the rotator in the clockwise direction
due to its helical structure As a result the liner motion of
the axis is transformed to lateral rotation of the r-TENG It
was found that our design could enable a quarter of circular
rotation provided with a linear motion of 6 mm After
electric transformation the measured output voltage from
the upper r-TENG is shown in Figure 5e There are two
voltage packs in a one cycle This is because rotation in the
counterclockwise direction occurs after the pressing force is
withdrawn because the four springs in the device (Figure 5a)
provides a restoring force It is also noticed that the
releasing process corresponds to higher electric output from
the upper unit which is attributed to the damping effect of
a soft cushion-like structure in the device In contrast the
transformed output voltage from the lower unit exhibits
higher amplitude for the pressing process After further
recti1047297cation and integration the combined output current
from the two r-TENGs has comparable amplitudes for both
pressing and releasing processes as shown in Figure 5g The
amplitude reaches around 5 mA which could charge alithium ion battery of 6 mA h in capacity from 25 V to
32 V in 10 min when the energy-harvesting device is
triggered at a frequency of 1 Hz
Compare with conventional magnetic generators that also
convert rotational motion into electricity the most promi-
nent advantage of the r-TENG is the high power density
Since the r-TENG relies on triboelectric effect at the
surface it requires very little amount of thin-1047297lm materials
Besides the materials used can be low-density polymers As
a result the r-TENG has exceptionally light weight and
small volume making is particularly suitable as an on-body
power source for portablewearable electronics
Conclusions
To summarize we reported a two-dimensional rotary TENG
Enabled by a design of two radial-arrayed 1047297ne electrodes
that are complementary patterns on the same plane the
planar-structured r-TENG can produce periodically changing
triboelectric potential that induces alternating currents
between electrodes Short-circuit current of 075 mA in
amplitude as well as voltage amplitude of 200 V was
generated at a rotating rate of 500 r min1 The unique
structural design enables various applications First the r-
TENG was 1047297rstly installed onto a bike to harvest energy from
pedaling The generated electricity can be used to charge a
cellphone Second the r-TENG can also be harnessed toharvest energy from arm swinging as well as foot pressure
during walking Through a power management circuit the
transformed output can be used to charge portable electro-
nics which unambiguously demonstrates the TENG as a
sustained power source for small electronics
Acknowledgment
The research was supported by the ldquoThousands Talentsrdquo
Program for Pioneer Researcher and His Innovation Team
China Patents have been 1047297led based on the research
presented here
Appendix A Supplementary Information
Supplementary data associated with this article can be found
in the online version at doi101016jnanoen201507011
References
[1] ZL Wang ACS Nano 7 (2013) 9533[2] X Wang J Song J Liu ZL Wang Science 316 (2007) 102
[3] SP Beeby MJ Tudor NM White Meas Sci Technol 17
(2006) 175
[4] J Scruggs P Jacob Science 323 (2009) 1176
[5] R Henderson Renew Energy 31 (2006) 271
[6] AD Kuo Science 309 (2005) 1686
[7] ZL Wang J Song Science 312 (2006) 242
[8] G Zhu B Peng J Chen Q Jing ZL Wang Nano Energy 14
(2015) 126
[9] ZL Wang J Chen L Lin Energy Environ Sci 8 (2015) 2250
[10] VA Jouanne Mech Eng Mag 128 (2006) 24
[11] S Kwon J Park WK Kim Y Yang E Lee CJ Han SY Park
J Lee YS Kim Energy Environ Sci 7 (2014) 3279
[12] W Huang G Wang F Gao Z Qiao G Wang M Chen
Y Deng L Tao Y Zhao X Fan L Sun J Phys Chem C 118(2014) 8783
[13] T Krupenkin JA Taylor Nat Commun 2 (2011) 448
[14] R Henderson Renew Energy 31 (2006) 271
[15] A Wolfbrandt IEEE Trans Magn 42 (2006) 1812
[16] Z Pi J Zhang C Wen ZB Zhang D Wu Nano Energy 7
(2014) 33
[17] G Zhu J Chen Q Jing T Zhang ZL Wang Nat Commun 5
(2014) 3426
[18] G Zhu Y Zhou P Bai X Meng Q Jing J Chen ZL Wang
Adv Mater 26 (2014) 3788
[19] J Chen J Yang Z Li X Fan Y Zi Q Jing H Guo Z Wen
KC Pradel S Niu ZL Wang ACS Nano 9 (2015) 3324
[20] X Meng G Zhu ZL Wang ACS Appl Mater Interfaces 6
(2014) 8011
[21] J Chen G Zhu J Yang Q Jing P Bai W Yang X Qi Y SuZL Wang ACS Nano 9 (2015) 105
[22] W Seung MK Gupta KY Lee KS Shin JH Lee TY Kim
S Kim J Lin JH Kim SW Kim ACS Nano 9 (2015) 3501
[23] J Chen G Zhu W Yang Q Jing P Bai Y Yang TC Hou Z
L Wang Adv Mater 25 (2013) 6094
[24] C Han C Zhang W Tang X Li ZL Wang Nano Res 8 (2014)
722
Shuang Yang Kuang received his bachelors
degree in Physics in Shandong University
Now he is pursuing his masterrsquos degree in
Beijing Institute of Nanoenergy and Nano-
system Chinese Academy of Science His
current research mainly focuses on applica-
tion and fabrication of triboelectricnanogenerators
Jun Chen received hisBSandMSin Elec-
trical Engineeringfromthe School of Electro-
nic Information and Communications at
HuazhongUniversity of Science and Technol-
ogy in2007 and2010 respectively and a
second MS in Biological Engineering from
the College of Engineering at The University
of Georgia in 2012 HeiscurrentlyaPhD
candidate
15Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 37
the rotator and the stator have a two-dimensional planar
structure resulting in small volume of the r-TENG The
detailed fabrication process was previously reported
[1724]
The electricity generation of the r-TENG relies on relative
rotation between the rotator and the stator Cycled change
of electric potential due to the motion of triboelectric
charges gives rise to alternating 1047298ows of electrons between
Figure 2 Electric output of a r-TENG that is 120 mm in diameter (a) Short-circuit current and (b) open-circuit voltage of the
r-TENG (c) Output current after transformation (d) Output voltage after transformation All the results are measured at a constant
rotation rate of 500 r min1
Figure 3 Demonstration of the r-TENG in harvesting energy from pedaling a bicycle (a) Transformed short-circuit current at a rotation
rate of 190 r min1 (b) Transformed open-circuit voltage at a rotation rate of 190 r min1 (c) Photograph showing 60 LEDs are being
lighted up simutanously when the bicyle is being pedaled (scale bar 8 cm) (d) Charging current and (e) charging voltage on the battery of
a cellphone (f) Photograph showing a cellphone is being charged when the bicycle is being pedaled (scale bar 8 cm)
SY Kuang et al12
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 47
electrodes The electricity generation process from a single
sector unit is depicted in Figure 1d and e Here two-
dimensional schematic illustrations of the charge distribu-
tion are used for interpretation To begin with when the
rotator rotates coaxially against the stator charge transfer
takes place at the contact interface Negative triboelectric
charges are produced on the PTFE surface since it has a
much stronger tendency to be negatively charged
(Figure 1d) On the open-circuit condition electrons cannot
transfer between electrodes The open-circuit voltage is
then essentially the electric potential difference between
the two electrodes At the initial state when the copper-
made stator is aligned with the left electrode (Figure 1d)
the electric potential of the left and right electrodes is
maximized and minimized respectively which corresponds
to a maximum electric potential difference between the
electrodes When the rotator starts to spin such a potential
difference will diminish to zero when the rotator reaches
the middle point Further rotation will result in a reversely
built-up electric potential difference between the electro-
des as illustrated in the Figure 1d If the two electrodes are
electrically connected namely on the short-circuit condi-tion the induced free electrons can 1047298ow between the
electrodes due to electrostatic induction As the rotator
starts to spin free electrons will keep 1047298owing from the left
electrode to the right electrode until the rotator is in
alignment with the right electrode (Figure 1e) Further
rotation will then generate a current in the opposite
direction
To characterize the electric output of the r-TENG a
programmable motor was employed to provide a mechanical
rotation source at a controlled rate At a rotating rate of
500 r min1 the short-circuit current (Isc) of the r-TENG has
a continuous ac manner at an amplitude of 075 mA and a
frequency of 750 Hz The open-circuit voltage (V oc) exhibits
a peak-to-peak value of 400 V at the same frequency In
order to realize impedance match between the TENG that
has high output impedance and conventional electronics
that are known for low input impedance we transformed
the electric output to enhance the output current at the
expense of the output voltage As shown in Figure 2c and d
the current amplitude is greatly boosted to about 16 mA
while the output voltage drops to about 32 V By doing so
the impedance match ensures that the maximum amount of
electric output can be extracted from the TENG for
practical use
To demonstrate practical applications we designed and
fabricated three types of devices that are based on the r-
TENG First we installed a r-TENG that is 150 mm in
diameter on the wheel axis of a 1047297tness bicycle When being
pedaled the relative rotation between the rotator and the
stator generates high-level electric output As shown in the
Figure 3a and b at a rotation rate of about 183 r min1 the
current amplitude after being tuned by transformers
reaches as high as 13 mA and the voltage amplitude
exceeds 36 V When directly using the generated electricitywe could simultaneously power over 20 LED lamps (12 V
06 W for each) which is demonstrated in Figure 3c and
Supplementary Movie S1 Besides powering small electro-
nics the electric output could be used to charge electro-
nics Here besides transformers we added recti1047297ers
capacitors and voltage regulators to construct a power
management circuit that can provide an output voltage at
a preset value (diagramed in Supplementary Figure S1)
When being plugged into a cellphone a charging system
consisting of the r-TENG and the power management circuit
can effectively charge a battery When being triggered by
pedaling the charging current shoots to 13 mA (Figure 3d)
Figure 4 Demonstration of the r-TENG for harvesting energy from human arm swinging (a) Schematic of the entire device (b) Diagram
of the device when the arm is stretched (c) Diagram of the device when the arm is bent (d) Short-circuit current and (e) open-circuitvoltage of the r-TENG at a swing frequency of 5 Hz (f) Transformed and recti1047297ed current On the right is an enlarged view of the current
signal (g) Photograph showing about 60 LEDs being lighted up simutaneously when the r-TENG is being swung (scale bar 10 cm)
(h) Charging curve of a capacitor with a capacitance of 4700 μF Inset is the diagram of a power management circuit
13Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 57
and the charging voltage 1047298uctuates around 7 V (Figure 3e)
The charging sign was immediately displayed on the cell-
phone screen as shown in Figure 3f and Supplementary
Movie S2
Supplementary material related to this article can be
found online at doi101016jnanoen201507011Second a wearable device for harvesting energy from
human body motion was demonstrated As shown in
Figure 4a the entire device mainly consists of three parts
a base a teethed rack and a r-TENG that is 10 mm in
diameter The r-TENG is attached to the upper arm while
the base is 1047297xed to the front arm around the wrist When
the arm is being swung a rotary torque is generated and
transferred to the r-TENG through the teethed rack and a
gear (Figure 4b and c) As a result the rotator is driven At a
swinging frequency of around 3 Hz the measured Isc(Figure 4d) and the V oc (Figure 4e) have amplitudes of up
to 025 mA and 120 V respectively For a single swinging
motion the instantaneous rotation rate varies and reaches
its peak value midway through the swinging Consequently
the obtained current pack in Figure 3f has the largest
amplitude in the middle However the voltage amplitude
in Figure 4e remains stable since it is velocity-independent
After being recti1047297ed and transformed the output currentbecomes unidirectional and reaches a peak value of 16 mA
The 1047298uctuating dc output in Figure 4g could not only
directly power a LED array (Figure 4h and Supplementary
Movie S3) but also charge a capacitor to have the energy
stored
Furthermore we speci1047297cally designed a device for har-
vesting energy from the foot pressure during normal walk-
ing The entire device is displayed in Figure 5 It has a
dimension of 6 cm by 6 cm by 3 cm Within in the device
two r-TENGs are stacked together in the vertical direction
As sketched in Figure 5b the two rotators share the same
substrate and rotate simultaneously The rotation is
Figure 5 Demonstration of the r-TENG for harvesting energy from foot pressure (a) Photograph of the entire device (b) Sketch
that illustrates the motions transmission component It transforms linear motion to rotation (c) Photograph showing an enlarged
view of the helical axis (d) Photograph showing an enlarged view of two r-TENGs that are stacked together (e) Transformed voltage
of the upper unit r-TENG On the right is an enlarged view of output voltage signal (f) Transformed voltage of the lower unit r-TENG
at a uniform walking rate On the right is an enlarged view of output voltage signal (g) Transformed and recti1047297ed current from the
two r-TENGs On the right is an enlarged view of output current signal (h) Charging curve of a battery with a capacity of 7 mA h
Inset is the corresponding diagram of a charging circuit
SY Kuang et al14
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 67
triggered by a helical axis in the vertical direction
(Figure 5c) When the helical axis is pressed down it exerts
a rotation torque to the rotator in the clockwise direction
due to its helical structure As a result the liner motion of
the axis is transformed to lateral rotation of the r-TENG It
was found that our design could enable a quarter of circular
rotation provided with a linear motion of 6 mm After
electric transformation the measured output voltage from
the upper r-TENG is shown in Figure 5e There are two
voltage packs in a one cycle This is because rotation in the
counterclockwise direction occurs after the pressing force is
withdrawn because the four springs in the device (Figure 5a)
provides a restoring force It is also noticed that the
releasing process corresponds to higher electric output from
the upper unit which is attributed to the damping effect of
a soft cushion-like structure in the device In contrast the
transformed output voltage from the lower unit exhibits
higher amplitude for the pressing process After further
recti1047297cation and integration the combined output current
from the two r-TENGs has comparable amplitudes for both
pressing and releasing processes as shown in Figure 5g The
amplitude reaches around 5 mA which could charge alithium ion battery of 6 mA h in capacity from 25 V to
32 V in 10 min when the energy-harvesting device is
triggered at a frequency of 1 Hz
Compare with conventional magnetic generators that also
convert rotational motion into electricity the most promi-
nent advantage of the r-TENG is the high power density
Since the r-TENG relies on triboelectric effect at the
surface it requires very little amount of thin-1047297lm materials
Besides the materials used can be low-density polymers As
a result the r-TENG has exceptionally light weight and
small volume making is particularly suitable as an on-body
power source for portablewearable electronics
Conclusions
To summarize we reported a two-dimensional rotary TENG
Enabled by a design of two radial-arrayed 1047297ne electrodes
that are complementary patterns on the same plane the
planar-structured r-TENG can produce periodically changing
triboelectric potential that induces alternating currents
between electrodes Short-circuit current of 075 mA in
amplitude as well as voltage amplitude of 200 V was
generated at a rotating rate of 500 r min1 The unique
structural design enables various applications First the r-
TENG was 1047297rstly installed onto a bike to harvest energy from
pedaling The generated electricity can be used to charge a
cellphone Second the r-TENG can also be harnessed toharvest energy from arm swinging as well as foot pressure
during walking Through a power management circuit the
transformed output can be used to charge portable electro-
nics which unambiguously demonstrates the TENG as a
sustained power source for small electronics
Acknowledgment
The research was supported by the ldquoThousands Talentsrdquo
Program for Pioneer Researcher and His Innovation Team
China Patents have been 1047297led based on the research
presented here
Appendix A Supplementary Information
Supplementary data associated with this article can be found
in the online version at doi101016jnanoen201507011
References
[1] ZL Wang ACS Nano 7 (2013) 9533[2] X Wang J Song J Liu ZL Wang Science 316 (2007) 102
[3] SP Beeby MJ Tudor NM White Meas Sci Technol 17
(2006) 175
[4] J Scruggs P Jacob Science 323 (2009) 1176
[5] R Henderson Renew Energy 31 (2006) 271
[6] AD Kuo Science 309 (2005) 1686
[7] ZL Wang J Song Science 312 (2006) 242
[8] G Zhu B Peng J Chen Q Jing ZL Wang Nano Energy 14
(2015) 126
[9] ZL Wang J Chen L Lin Energy Environ Sci 8 (2015) 2250
[10] VA Jouanne Mech Eng Mag 128 (2006) 24
[11] S Kwon J Park WK Kim Y Yang E Lee CJ Han SY Park
J Lee YS Kim Energy Environ Sci 7 (2014) 3279
[12] W Huang G Wang F Gao Z Qiao G Wang M Chen
Y Deng L Tao Y Zhao X Fan L Sun J Phys Chem C 118(2014) 8783
[13] T Krupenkin JA Taylor Nat Commun 2 (2011) 448
[14] R Henderson Renew Energy 31 (2006) 271
[15] A Wolfbrandt IEEE Trans Magn 42 (2006) 1812
[16] Z Pi J Zhang C Wen ZB Zhang D Wu Nano Energy 7
(2014) 33
[17] G Zhu J Chen Q Jing T Zhang ZL Wang Nat Commun 5
(2014) 3426
[18] G Zhu Y Zhou P Bai X Meng Q Jing J Chen ZL Wang
Adv Mater 26 (2014) 3788
[19] J Chen J Yang Z Li X Fan Y Zi Q Jing H Guo Z Wen
KC Pradel S Niu ZL Wang ACS Nano 9 (2015) 3324
[20] X Meng G Zhu ZL Wang ACS Appl Mater Interfaces 6
(2014) 8011
[21] J Chen G Zhu J Yang Q Jing P Bai W Yang X Qi Y SuZL Wang ACS Nano 9 (2015) 105
[22] W Seung MK Gupta KY Lee KS Shin JH Lee TY Kim
S Kim J Lin JH Kim SW Kim ACS Nano 9 (2015) 3501
[23] J Chen G Zhu W Yang Q Jing P Bai Y Yang TC Hou Z
L Wang Adv Mater 25 (2013) 6094
[24] C Han C Zhang W Tang X Li ZL Wang Nano Res 8 (2014)
722
Shuang Yang Kuang received his bachelors
degree in Physics in Shandong University
Now he is pursuing his masterrsquos degree in
Beijing Institute of Nanoenergy and Nano-
system Chinese Academy of Science His
current research mainly focuses on applica-
tion and fabrication of triboelectricnanogenerators
Jun Chen received hisBSandMSin Elec-
trical Engineeringfromthe School of Electro-
nic Information and Communications at
HuazhongUniversity of Science and Technol-
ogy in2007 and2010 respectively and a
second MS in Biological Engineering from
the College of Engineering at The University
of Georgia in 2012 HeiscurrentlyaPhD
candidate
15Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 47
electrodes The electricity generation process from a single
sector unit is depicted in Figure 1d and e Here two-
dimensional schematic illustrations of the charge distribu-
tion are used for interpretation To begin with when the
rotator rotates coaxially against the stator charge transfer
takes place at the contact interface Negative triboelectric
charges are produced on the PTFE surface since it has a
much stronger tendency to be negatively charged
(Figure 1d) On the open-circuit condition electrons cannot
transfer between electrodes The open-circuit voltage is
then essentially the electric potential difference between
the two electrodes At the initial state when the copper-
made stator is aligned with the left electrode (Figure 1d)
the electric potential of the left and right electrodes is
maximized and minimized respectively which corresponds
to a maximum electric potential difference between the
electrodes When the rotator starts to spin such a potential
difference will diminish to zero when the rotator reaches
the middle point Further rotation will result in a reversely
built-up electric potential difference between the electro-
des as illustrated in the Figure 1d If the two electrodes are
electrically connected namely on the short-circuit condi-tion the induced free electrons can 1047298ow between the
electrodes due to electrostatic induction As the rotator
starts to spin free electrons will keep 1047298owing from the left
electrode to the right electrode until the rotator is in
alignment with the right electrode (Figure 1e) Further
rotation will then generate a current in the opposite
direction
To characterize the electric output of the r-TENG a
programmable motor was employed to provide a mechanical
rotation source at a controlled rate At a rotating rate of
500 r min1 the short-circuit current (Isc) of the r-TENG has
a continuous ac manner at an amplitude of 075 mA and a
frequency of 750 Hz The open-circuit voltage (V oc) exhibits
a peak-to-peak value of 400 V at the same frequency In
order to realize impedance match between the TENG that
has high output impedance and conventional electronics
that are known for low input impedance we transformed
the electric output to enhance the output current at the
expense of the output voltage As shown in Figure 2c and d
the current amplitude is greatly boosted to about 16 mA
while the output voltage drops to about 32 V By doing so
the impedance match ensures that the maximum amount of
electric output can be extracted from the TENG for
practical use
To demonstrate practical applications we designed and
fabricated three types of devices that are based on the r-
TENG First we installed a r-TENG that is 150 mm in
diameter on the wheel axis of a 1047297tness bicycle When being
pedaled the relative rotation between the rotator and the
stator generates high-level electric output As shown in the
Figure 3a and b at a rotation rate of about 183 r min1 the
current amplitude after being tuned by transformers
reaches as high as 13 mA and the voltage amplitude
exceeds 36 V When directly using the generated electricitywe could simultaneously power over 20 LED lamps (12 V
06 W for each) which is demonstrated in Figure 3c and
Supplementary Movie S1 Besides powering small electro-
nics the electric output could be used to charge electro-
nics Here besides transformers we added recti1047297ers
capacitors and voltage regulators to construct a power
management circuit that can provide an output voltage at
a preset value (diagramed in Supplementary Figure S1)
When being plugged into a cellphone a charging system
consisting of the r-TENG and the power management circuit
can effectively charge a battery When being triggered by
pedaling the charging current shoots to 13 mA (Figure 3d)
Figure 4 Demonstration of the r-TENG for harvesting energy from human arm swinging (a) Schematic of the entire device (b) Diagram
of the device when the arm is stretched (c) Diagram of the device when the arm is bent (d) Short-circuit current and (e) open-circuitvoltage of the r-TENG at a swing frequency of 5 Hz (f) Transformed and recti1047297ed current On the right is an enlarged view of the current
signal (g) Photograph showing about 60 LEDs being lighted up simutaneously when the r-TENG is being swung (scale bar 10 cm)
(h) Charging curve of a capacitor with a capacitance of 4700 μF Inset is the diagram of a power management circuit
13Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 57
and the charging voltage 1047298uctuates around 7 V (Figure 3e)
The charging sign was immediately displayed on the cell-
phone screen as shown in Figure 3f and Supplementary
Movie S2
Supplementary material related to this article can be
found online at doi101016jnanoen201507011Second a wearable device for harvesting energy from
human body motion was demonstrated As shown in
Figure 4a the entire device mainly consists of three parts
a base a teethed rack and a r-TENG that is 10 mm in
diameter The r-TENG is attached to the upper arm while
the base is 1047297xed to the front arm around the wrist When
the arm is being swung a rotary torque is generated and
transferred to the r-TENG through the teethed rack and a
gear (Figure 4b and c) As a result the rotator is driven At a
swinging frequency of around 3 Hz the measured Isc(Figure 4d) and the V oc (Figure 4e) have amplitudes of up
to 025 mA and 120 V respectively For a single swinging
motion the instantaneous rotation rate varies and reaches
its peak value midway through the swinging Consequently
the obtained current pack in Figure 3f has the largest
amplitude in the middle However the voltage amplitude
in Figure 4e remains stable since it is velocity-independent
After being recti1047297ed and transformed the output currentbecomes unidirectional and reaches a peak value of 16 mA
The 1047298uctuating dc output in Figure 4g could not only
directly power a LED array (Figure 4h and Supplementary
Movie S3) but also charge a capacitor to have the energy
stored
Furthermore we speci1047297cally designed a device for har-
vesting energy from the foot pressure during normal walk-
ing The entire device is displayed in Figure 5 It has a
dimension of 6 cm by 6 cm by 3 cm Within in the device
two r-TENGs are stacked together in the vertical direction
As sketched in Figure 5b the two rotators share the same
substrate and rotate simultaneously The rotation is
Figure 5 Demonstration of the r-TENG for harvesting energy from foot pressure (a) Photograph of the entire device (b) Sketch
that illustrates the motions transmission component It transforms linear motion to rotation (c) Photograph showing an enlarged
view of the helical axis (d) Photograph showing an enlarged view of two r-TENGs that are stacked together (e) Transformed voltage
of the upper unit r-TENG On the right is an enlarged view of output voltage signal (f) Transformed voltage of the lower unit r-TENG
at a uniform walking rate On the right is an enlarged view of output voltage signal (g) Transformed and recti1047297ed current from the
two r-TENGs On the right is an enlarged view of output current signal (h) Charging curve of a battery with a capacity of 7 mA h
Inset is the corresponding diagram of a charging circuit
SY Kuang et al14
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 67
triggered by a helical axis in the vertical direction
(Figure 5c) When the helical axis is pressed down it exerts
a rotation torque to the rotator in the clockwise direction
due to its helical structure As a result the liner motion of
the axis is transformed to lateral rotation of the r-TENG It
was found that our design could enable a quarter of circular
rotation provided with a linear motion of 6 mm After
electric transformation the measured output voltage from
the upper r-TENG is shown in Figure 5e There are two
voltage packs in a one cycle This is because rotation in the
counterclockwise direction occurs after the pressing force is
withdrawn because the four springs in the device (Figure 5a)
provides a restoring force It is also noticed that the
releasing process corresponds to higher electric output from
the upper unit which is attributed to the damping effect of
a soft cushion-like structure in the device In contrast the
transformed output voltage from the lower unit exhibits
higher amplitude for the pressing process After further
recti1047297cation and integration the combined output current
from the two r-TENGs has comparable amplitudes for both
pressing and releasing processes as shown in Figure 5g The
amplitude reaches around 5 mA which could charge alithium ion battery of 6 mA h in capacity from 25 V to
32 V in 10 min when the energy-harvesting device is
triggered at a frequency of 1 Hz
Compare with conventional magnetic generators that also
convert rotational motion into electricity the most promi-
nent advantage of the r-TENG is the high power density
Since the r-TENG relies on triboelectric effect at the
surface it requires very little amount of thin-1047297lm materials
Besides the materials used can be low-density polymers As
a result the r-TENG has exceptionally light weight and
small volume making is particularly suitable as an on-body
power source for portablewearable electronics
Conclusions
To summarize we reported a two-dimensional rotary TENG
Enabled by a design of two radial-arrayed 1047297ne electrodes
that are complementary patterns on the same plane the
planar-structured r-TENG can produce periodically changing
triboelectric potential that induces alternating currents
between electrodes Short-circuit current of 075 mA in
amplitude as well as voltage amplitude of 200 V was
generated at a rotating rate of 500 r min1 The unique
structural design enables various applications First the r-
TENG was 1047297rstly installed onto a bike to harvest energy from
pedaling The generated electricity can be used to charge a
cellphone Second the r-TENG can also be harnessed toharvest energy from arm swinging as well as foot pressure
during walking Through a power management circuit the
transformed output can be used to charge portable electro-
nics which unambiguously demonstrates the TENG as a
sustained power source for small electronics
Acknowledgment
The research was supported by the ldquoThousands Talentsrdquo
Program for Pioneer Researcher and His Innovation Team
China Patents have been 1047297led based on the research
presented here
Appendix A Supplementary Information
Supplementary data associated with this article can be found
in the online version at doi101016jnanoen201507011
References
[1] ZL Wang ACS Nano 7 (2013) 9533[2] X Wang J Song J Liu ZL Wang Science 316 (2007) 102
[3] SP Beeby MJ Tudor NM White Meas Sci Technol 17
(2006) 175
[4] J Scruggs P Jacob Science 323 (2009) 1176
[5] R Henderson Renew Energy 31 (2006) 271
[6] AD Kuo Science 309 (2005) 1686
[7] ZL Wang J Song Science 312 (2006) 242
[8] G Zhu B Peng J Chen Q Jing ZL Wang Nano Energy 14
(2015) 126
[9] ZL Wang J Chen L Lin Energy Environ Sci 8 (2015) 2250
[10] VA Jouanne Mech Eng Mag 128 (2006) 24
[11] S Kwon J Park WK Kim Y Yang E Lee CJ Han SY Park
J Lee YS Kim Energy Environ Sci 7 (2014) 3279
[12] W Huang G Wang F Gao Z Qiao G Wang M Chen
Y Deng L Tao Y Zhao X Fan L Sun J Phys Chem C 118(2014) 8783
[13] T Krupenkin JA Taylor Nat Commun 2 (2011) 448
[14] R Henderson Renew Energy 31 (2006) 271
[15] A Wolfbrandt IEEE Trans Magn 42 (2006) 1812
[16] Z Pi J Zhang C Wen ZB Zhang D Wu Nano Energy 7
(2014) 33
[17] G Zhu J Chen Q Jing T Zhang ZL Wang Nat Commun 5
(2014) 3426
[18] G Zhu Y Zhou P Bai X Meng Q Jing J Chen ZL Wang
Adv Mater 26 (2014) 3788
[19] J Chen J Yang Z Li X Fan Y Zi Q Jing H Guo Z Wen
KC Pradel S Niu ZL Wang ACS Nano 9 (2015) 3324
[20] X Meng G Zhu ZL Wang ACS Appl Mater Interfaces 6
(2014) 8011
[21] J Chen G Zhu J Yang Q Jing P Bai W Yang X Qi Y SuZL Wang ACS Nano 9 (2015) 105
[22] W Seung MK Gupta KY Lee KS Shin JH Lee TY Kim
S Kim J Lin JH Kim SW Kim ACS Nano 9 (2015) 3501
[23] J Chen G Zhu W Yang Q Jing P Bai Y Yang TC Hou Z
L Wang Adv Mater 25 (2013) 6094
[24] C Han C Zhang W Tang X Li ZL Wang Nano Res 8 (2014)
722
Shuang Yang Kuang received his bachelors
degree in Physics in Shandong University
Now he is pursuing his masterrsquos degree in
Beijing Institute of Nanoenergy and Nano-
system Chinese Academy of Science His
current research mainly focuses on applica-
tion and fabrication of triboelectricnanogenerators
Jun Chen received hisBSandMSin Elec-
trical Engineeringfromthe School of Electro-
nic Information and Communications at
HuazhongUniversity of Science and Technol-
ogy in2007 and2010 respectively and a
second MS in Biological Engineering from
the College of Engineering at The University
of Georgia in 2012 HeiscurrentlyaPhD
candidate
15Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 57
and the charging voltage 1047298uctuates around 7 V (Figure 3e)
The charging sign was immediately displayed on the cell-
phone screen as shown in Figure 3f and Supplementary
Movie S2
Supplementary material related to this article can be
found online at doi101016jnanoen201507011Second a wearable device for harvesting energy from
human body motion was demonstrated As shown in
Figure 4a the entire device mainly consists of three parts
a base a teethed rack and a r-TENG that is 10 mm in
diameter The r-TENG is attached to the upper arm while
the base is 1047297xed to the front arm around the wrist When
the arm is being swung a rotary torque is generated and
transferred to the r-TENG through the teethed rack and a
gear (Figure 4b and c) As a result the rotator is driven At a
swinging frequency of around 3 Hz the measured Isc(Figure 4d) and the V oc (Figure 4e) have amplitudes of up
to 025 mA and 120 V respectively For a single swinging
motion the instantaneous rotation rate varies and reaches
its peak value midway through the swinging Consequently
the obtained current pack in Figure 3f has the largest
amplitude in the middle However the voltage amplitude
in Figure 4e remains stable since it is velocity-independent
After being recti1047297ed and transformed the output currentbecomes unidirectional and reaches a peak value of 16 mA
The 1047298uctuating dc output in Figure 4g could not only
directly power a LED array (Figure 4h and Supplementary
Movie S3) but also charge a capacitor to have the energy
stored
Furthermore we speci1047297cally designed a device for har-
vesting energy from the foot pressure during normal walk-
ing The entire device is displayed in Figure 5 It has a
dimension of 6 cm by 6 cm by 3 cm Within in the device
two r-TENGs are stacked together in the vertical direction
As sketched in Figure 5b the two rotators share the same
substrate and rotate simultaneously The rotation is
Figure 5 Demonstration of the r-TENG for harvesting energy from foot pressure (a) Photograph of the entire device (b) Sketch
that illustrates the motions transmission component It transforms linear motion to rotation (c) Photograph showing an enlarged
view of the helical axis (d) Photograph showing an enlarged view of two r-TENGs that are stacked together (e) Transformed voltage
of the upper unit r-TENG On the right is an enlarged view of output voltage signal (f) Transformed voltage of the lower unit r-TENG
at a uniform walking rate On the right is an enlarged view of output voltage signal (g) Transformed and recti1047297ed current from the
two r-TENGs On the right is an enlarged view of output current signal (h) Charging curve of a battery with a capacity of 7 mA h
Inset is the corresponding diagram of a charging circuit
SY Kuang et al14
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 67
triggered by a helical axis in the vertical direction
(Figure 5c) When the helical axis is pressed down it exerts
a rotation torque to the rotator in the clockwise direction
due to its helical structure As a result the liner motion of
the axis is transformed to lateral rotation of the r-TENG It
was found that our design could enable a quarter of circular
rotation provided with a linear motion of 6 mm After
electric transformation the measured output voltage from
the upper r-TENG is shown in Figure 5e There are two
voltage packs in a one cycle This is because rotation in the
counterclockwise direction occurs after the pressing force is
withdrawn because the four springs in the device (Figure 5a)
provides a restoring force It is also noticed that the
releasing process corresponds to higher electric output from
the upper unit which is attributed to the damping effect of
a soft cushion-like structure in the device In contrast the
transformed output voltage from the lower unit exhibits
higher amplitude for the pressing process After further
recti1047297cation and integration the combined output current
from the two r-TENGs has comparable amplitudes for both
pressing and releasing processes as shown in Figure 5g The
amplitude reaches around 5 mA which could charge alithium ion battery of 6 mA h in capacity from 25 V to
32 V in 10 min when the energy-harvesting device is
triggered at a frequency of 1 Hz
Compare with conventional magnetic generators that also
convert rotational motion into electricity the most promi-
nent advantage of the r-TENG is the high power density
Since the r-TENG relies on triboelectric effect at the
surface it requires very little amount of thin-1047297lm materials
Besides the materials used can be low-density polymers As
a result the r-TENG has exceptionally light weight and
small volume making is particularly suitable as an on-body
power source for portablewearable electronics
Conclusions
To summarize we reported a two-dimensional rotary TENG
Enabled by a design of two radial-arrayed 1047297ne electrodes
that are complementary patterns on the same plane the
planar-structured r-TENG can produce periodically changing
triboelectric potential that induces alternating currents
between electrodes Short-circuit current of 075 mA in
amplitude as well as voltage amplitude of 200 V was
generated at a rotating rate of 500 r min1 The unique
structural design enables various applications First the r-
TENG was 1047297rstly installed onto a bike to harvest energy from
pedaling The generated electricity can be used to charge a
cellphone Second the r-TENG can also be harnessed toharvest energy from arm swinging as well as foot pressure
during walking Through a power management circuit the
transformed output can be used to charge portable electro-
nics which unambiguously demonstrates the TENG as a
sustained power source for small electronics
Acknowledgment
The research was supported by the ldquoThousands Talentsrdquo
Program for Pioneer Researcher and His Innovation Team
China Patents have been 1047297led based on the research
presented here
Appendix A Supplementary Information
Supplementary data associated with this article can be found
in the online version at doi101016jnanoen201507011
References
[1] ZL Wang ACS Nano 7 (2013) 9533[2] X Wang J Song J Liu ZL Wang Science 316 (2007) 102
[3] SP Beeby MJ Tudor NM White Meas Sci Technol 17
(2006) 175
[4] J Scruggs P Jacob Science 323 (2009) 1176
[5] R Henderson Renew Energy 31 (2006) 271
[6] AD Kuo Science 309 (2005) 1686
[7] ZL Wang J Song Science 312 (2006) 242
[8] G Zhu B Peng J Chen Q Jing ZL Wang Nano Energy 14
(2015) 126
[9] ZL Wang J Chen L Lin Energy Environ Sci 8 (2015) 2250
[10] VA Jouanne Mech Eng Mag 128 (2006) 24
[11] S Kwon J Park WK Kim Y Yang E Lee CJ Han SY Park
J Lee YS Kim Energy Environ Sci 7 (2014) 3279
[12] W Huang G Wang F Gao Z Qiao G Wang M Chen
Y Deng L Tao Y Zhao X Fan L Sun J Phys Chem C 118(2014) 8783
[13] T Krupenkin JA Taylor Nat Commun 2 (2011) 448
[14] R Henderson Renew Energy 31 (2006) 271
[15] A Wolfbrandt IEEE Trans Magn 42 (2006) 1812
[16] Z Pi J Zhang C Wen ZB Zhang D Wu Nano Energy 7
(2014) 33
[17] G Zhu J Chen Q Jing T Zhang ZL Wang Nat Commun 5
(2014) 3426
[18] G Zhu Y Zhou P Bai X Meng Q Jing J Chen ZL Wang
Adv Mater 26 (2014) 3788
[19] J Chen J Yang Z Li X Fan Y Zi Q Jing H Guo Z Wen
KC Pradel S Niu ZL Wang ACS Nano 9 (2015) 3324
[20] X Meng G Zhu ZL Wang ACS Appl Mater Interfaces 6
(2014) 8011
[21] J Chen G Zhu J Yang Q Jing P Bai W Yang X Qi Y SuZL Wang ACS Nano 9 (2015) 105
[22] W Seung MK Gupta KY Lee KS Shin JH Lee TY Kim
S Kim J Lin JH Kim SW Kim ACS Nano 9 (2015) 3501
[23] J Chen G Zhu W Yang Q Jing P Bai Y Yang TC Hou Z
L Wang Adv Mater 25 (2013) 6094
[24] C Han C Zhang W Tang X Li ZL Wang Nano Res 8 (2014)
722
Shuang Yang Kuang received his bachelors
degree in Physics in Shandong University
Now he is pursuing his masterrsquos degree in
Beijing Institute of Nanoenergy and Nano-
system Chinese Academy of Science His
current research mainly focuses on applica-
tion and fabrication of triboelectricnanogenerators
Jun Chen received hisBSandMSin Elec-
trical Engineeringfromthe School of Electro-
nic Information and Communications at
HuazhongUniversity of Science and Technol-
ogy in2007 and2010 respectively and a
second MS in Biological Engineering from
the College of Engineering at The University
of Georgia in 2012 HeiscurrentlyaPhD
candidate
15Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 67
triggered by a helical axis in the vertical direction
(Figure 5c) When the helical axis is pressed down it exerts
a rotation torque to the rotator in the clockwise direction
due to its helical structure As a result the liner motion of
the axis is transformed to lateral rotation of the r-TENG It
was found that our design could enable a quarter of circular
rotation provided with a linear motion of 6 mm After
electric transformation the measured output voltage from
the upper r-TENG is shown in Figure 5e There are two
voltage packs in a one cycle This is because rotation in the
counterclockwise direction occurs after the pressing force is
withdrawn because the four springs in the device (Figure 5a)
provides a restoring force It is also noticed that the
releasing process corresponds to higher electric output from
the upper unit which is attributed to the damping effect of
a soft cushion-like structure in the device In contrast the
transformed output voltage from the lower unit exhibits
higher amplitude for the pressing process After further
recti1047297cation and integration the combined output current
from the two r-TENGs has comparable amplitudes for both
pressing and releasing processes as shown in Figure 5g The
amplitude reaches around 5 mA which could charge alithium ion battery of 6 mA h in capacity from 25 V to
32 V in 10 min when the energy-harvesting device is
triggered at a frequency of 1 Hz
Compare with conventional magnetic generators that also
convert rotational motion into electricity the most promi-
nent advantage of the r-TENG is the high power density
Since the r-TENG relies on triboelectric effect at the
surface it requires very little amount of thin-1047297lm materials
Besides the materials used can be low-density polymers As
a result the r-TENG has exceptionally light weight and
small volume making is particularly suitable as an on-body
power source for portablewearable electronics
Conclusions
To summarize we reported a two-dimensional rotary TENG
Enabled by a design of two radial-arrayed 1047297ne electrodes
that are complementary patterns on the same plane the
planar-structured r-TENG can produce periodically changing
triboelectric potential that induces alternating currents
between electrodes Short-circuit current of 075 mA in
amplitude as well as voltage amplitude of 200 V was
generated at a rotating rate of 500 r min1 The unique
structural design enables various applications First the r-
TENG was 1047297rstly installed onto a bike to harvest energy from
pedaling The generated electricity can be used to charge a
cellphone Second the r-TENG can also be harnessed toharvest energy from arm swinging as well as foot pressure
during walking Through a power management circuit the
transformed output can be used to charge portable electro-
nics which unambiguously demonstrates the TENG as a
sustained power source for small electronics
Acknowledgment
The research was supported by the ldquoThousands Talentsrdquo
Program for Pioneer Researcher and His Innovation Team
China Patents have been 1047297led based on the research
presented here
Appendix A Supplementary Information
Supplementary data associated with this article can be found
in the online version at doi101016jnanoen201507011
References
[1] ZL Wang ACS Nano 7 (2013) 9533[2] X Wang J Song J Liu ZL Wang Science 316 (2007) 102
[3] SP Beeby MJ Tudor NM White Meas Sci Technol 17
(2006) 175
[4] J Scruggs P Jacob Science 323 (2009) 1176
[5] R Henderson Renew Energy 31 (2006) 271
[6] AD Kuo Science 309 (2005) 1686
[7] ZL Wang J Song Science 312 (2006) 242
[8] G Zhu B Peng J Chen Q Jing ZL Wang Nano Energy 14
(2015) 126
[9] ZL Wang J Chen L Lin Energy Environ Sci 8 (2015) 2250
[10] VA Jouanne Mech Eng Mag 128 (2006) 24
[11] S Kwon J Park WK Kim Y Yang E Lee CJ Han SY Park
J Lee YS Kim Energy Environ Sci 7 (2014) 3279
[12] W Huang G Wang F Gao Z Qiao G Wang M Chen
Y Deng L Tao Y Zhao X Fan L Sun J Phys Chem C 118(2014) 8783
[13] T Krupenkin JA Taylor Nat Commun 2 (2011) 448
[14] R Henderson Renew Energy 31 (2006) 271
[15] A Wolfbrandt IEEE Trans Magn 42 (2006) 1812
[16] Z Pi J Zhang C Wen ZB Zhang D Wu Nano Energy 7
(2014) 33
[17] G Zhu J Chen Q Jing T Zhang ZL Wang Nat Commun 5
(2014) 3426
[18] G Zhu Y Zhou P Bai X Meng Q Jing J Chen ZL Wang
Adv Mater 26 (2014) 3788
[19] J Chen J Yang Z Li X Fan Y Zi Q Jing H Guo Z Wen
KC Pradel S Niu ZL Wang ACS Nano 9 (2015) 3324
[20] X Meng G Zhu ZL Wang ACS Appl Mater Interfaces 6
(2014) 8011
[21] J Chen G Zhu J Yang Q Jing P Bai W Yang X Qi Y SuZL Wang ACS Nano 9 (2015) 105
[22] W Seung MK Gupta KY Lee KS Shin JH Lee TY Kim
S Kim J Lin JH Kim SW Kim ACS Nano 9 (2015) 3501
[23] J Chen G Zhu W Yang Q Jing P Bai Y Yang TC Hou Z
L Wang Adv Mater 25 (2013) 6094
[24] C Han C Zhang W Tang X Li ZL Wang Nano Res 8 (2014)
722
Shuang Yang Kuang received his bachelors
degree in Physics in Shandong University
Now he is pursuing his masterrsquos degree in
Beijing Institute of Nanoenergy and Nano-
system Chinese Academy of Science His
current research mainly focuses on applica-
tion and fabrication of triboelectricnanogenerators
Jun Chen received hisBSandMSin Elec-
trical Engineeringfromthe School of Electro-
nic Information and Communications at
HuazhongUniversity of Science and Technol-
ogy in2007 and2010 respectively and a
second MS in Biological Engineering from
the College of Engineering at The University
of Georgia in 2012 HeiscurrentlyaPhD
candidate
15Two-dimensional rotary triboelectric nanogenerator
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16
7232019 Two-dimensional Rotary Triboelectric
httpslidepdfcomreaderfulltwo-dimensional-rotary-triboelectric 77
intheSchoolofMaterialsScienceand Engineeringat TheGeorgiaInstitu-
teofTechnology Hisresearchfocusesprimarilyonnanomaterial-based
energy harvesting energy storage active sensingand self-powered
micro-nano-systems
Xiao Bei Cheng is a graduate student at the
Chongqing University of Posts and Telecom-
munications He received his Bachelor
degree in Electronic Information Scienceand Technology at Henan Polytechnic Uni-
versity in 2012 His current research mainly
focuses on theenergy conversion and collec-
tion surface tribocharging theory and
power management which improve energy
ef 1047297ciency
Dr Guang Zhu is a professor at Beijing
Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences He received
his PhD degree in Materials Science and
Engineering at Georgia Tech in 2013 and his
Bachelor degree in Materials Science and
Engineering at Beijing University of Chemi-
cal Technology in 2008 His current research
mainly focuses on designing fabrication
and implementation of innovative miniaturized high-ef 1047297ciency
generators that harvest and convert ambient mechanical energy
into electricity
Dr Zhong Lin Wang is a Hightower Chairand
Regentsrsquo Professor at Georgia Tech Heis
also the Chief scientist and Director forthe
Beijing Institute of Nanoenergy andNanosys-
tems Chinese Academy of SciencesHis dis-covery and breakthroughs in
developingnanogenerators establish the
principleand technological road map forhar-
vesting mechanical energy from environ-
mentaland biological systems for
poweringpersonal electronics He coined andpioneered the 1047297eld of
piezotronics and piezo-phototronics byintroducing piezoelectric
potential gated charge transport processin fabricating new electro-
nic and optoelectronic devices
SY Kuang et al16