Nonlinear Energy Harvesting from vibrations - DIEES - · PDF file ·...

1 December 17, 2014

DIEEI University of Catania – Italy

Nonlinear Energy Harvesting from vibrations

2 December 17, 2014

•The Energy Harvesting issue •Non linear EH vs linear EH •The proposed solutions & the Real LabScale Prototypes

The mechanical characterization

The electrical performances

Outline

3 December 17, 2014

A WSN consists of:

Sensors and actuators

Microcontroller (μC)

Radio

Power si

mp

le v

isio

n o

f a

WSN

no

des

THE ENERGY HARVESTING ISSUE

Development of solutions aimed at powering wireless nodes by exploiting the energy scavenged from their operating environment in order to reduce (or eliminate) the need of periodic replacements of batteries (environmentally friendly).

4 December 17, 2014

Benefits: Maintenance free – no need to replace batteries

The technologies employed, variously convert

Solar radiation (PV) Wind Human power Body fluids Heat differences Vibration or other movements RF Vegetation Ultraviolet Visible light or Infrared …. more options coming along

to electricity (DC current).

WHAT IS ENERGY HARVESTING?

Requires expertise from all aspects of physics, including:

Energy capture (sporadic, irregular energy

rather than sinusoidal)

Energy storage

Metrology

Material science

Systems engineering

Energy harvesting or scavenging is a process that captures small amounts of energy that would otherwise be lost as heat, light, sound, vibration or movement, to provide electrical power for small electronic and electrical devices making them self-sufficient (replace batteries).

Improve efficiency – eg computing costs would be cut significantly if waste heat were harvested and used to help power the computer

Enable new technology – eg wireless sensor networks (WSN) Environmentally friendly – disposal of batteries is tightly regulated because

they contain chemicals and metals that are harmful to the environment and hazardous to human health

Opens up new applications – such as deploying EH sensors to monitor remote or underwater locations

5 December 17, 2014

Autonomous sensors

Embedded sensor nodes

Recharging the batteries

Smart systems

Autonomous WSN

NEEDS

Remove the expense, inconvenience and pollution that results from frequent replacement of batteries in small devices Environmental savings Needs of the Third World (education and lighting) Needs in developed countries

Sou

rce

Sou

tha

mp

ton

Un

iver

sity

Ho

spit

al U

K

Source: IDTechEx report “Energy Harvesting and Storage for Electronic Devices 2009-2019”

6 December 17, 2014

POWER REQUIREMENTS OF ENERGY HARVESTING

Source: IDTechEx report “Energy Harvesting and Storage for Electronic Devices 2009-2019”.

Sensors typically require 1 to 50 mW. It is impractical or extremely expensive to change batteries in sensors in most of the envisaged locations. The same is true of active RFID but with a wider range of required power.

7 December 17, 2014

POTENTIAL ENERGY HARVESTING MARKETS So

urc

e: ID

Tech

Ex r

epo

rt “

Ener

gy

Ha

rves

tin

g a

nd

Sto

rag

e fo

r El

ectr

on

ic D

evic

es 2

00

9-2

01

9”.

Global market value of energy harvesting for small electronic and electrical devices in 2014

8 December 17, 2014

RESEARCH DEVELOPMENTS

Tame bats A surveillance bat that will employ solar, wind, vibration and “other sources” to recharge its battery ($22.5 million)

COM-BAT surveillance bat

Sou

rce

Un

iver

sity

of

Mic

hig

an

15 centimeter, one watt robotic spy

Invisible harvesting Many new printed electronic devices are transparent including metal oxide transistors.

Transparent, flexible printed battery that charges in one minute

Sou

rce

Wa

sed

a U

niv

ersi

ty

Electricity for underwater electronics Source Ocean Power Technologies

a flag-like structure that moved with the tides to generate electricity

Vortex Hydro Energy VIVACE converter: a hydrokinetic power generating device, which harnesses hydrokinetic energy of river and ocean currents. It uses the physical phenomenon of vortex induced vibration in which water current flows around cylinders inducing transverse motion. The energy contained in the movement of the cylinder is then converted to electricity.

Patent of University of Michigan

9 December 17, 2014

New healthcare harvesting A wearable battery-free wireless 2-channel EEG system integrated into a device resembling headphones has been developed, powered by a hybrid power supply using body heat and ambient light.

New polymer and metal alloy capabilities Other promising approaches involve organic piezoelectric or electroactive polymers, possibly exhibiting electret properties as well.

People power Implanted defibrillators and pacemakers powered electrodynamically from the human heart that they administer

Biobatteries harvest body fluids

Nantennas

Source Idaho National Laboratory

Nantenna array harvesting infrared

RESEARCH DEVELOPMENTS

Solar cells that work in the dark photovoltaics that can convert infrared as well as light into electricity

MEMS Microminiature versions of favourite EH technologies (electrodynamics, thermoelectrics, piezoelectrics and photovoltaics), often with exotic new materials.

10 December 17, 2014

Energy scavenging from wasted ambient energy sources: light, heat, vibrations, RF radiation, etc..

Energy Harvesting sources

courtesy of Zhejiang Solar Panel

courtesy of Perpetua Power Source Technologies

cou

rtes

y o

f b

cp-e

ner

gia

Princeton University

Wireless Sensor and energy harvester

courtesy of SolarBotanic

Source: Georgia Tech


•Piezoelectric materials Mechanical stress ↔ electrical signal Human motion, low-frequency vibrations, and acoustic noise are just some of the potential sources that could be harvested by piezoelectric materials. Examples of piezoelectric EH:

Battery-less remote control – the force used to press a button is sufficient to power a wireless radio or infrared signal

Piezoelectric floor tiles – there is much interest in harvesting the kinetic energy generated by the footsteps of crowds to power ticket gates and display systems

Car tyre pressure sensors – EH sensors attached inside the tyres continuously monitor the pressure and send the information to a display on the dashboard

•Thermoelectric materials Temperature differences across the material ↔ electric voltage A temperature across a thermoelectric crystal (i.e. one side is warmer/cooler than the other), it causes a voltage across the crystal. Example of thermoelectric EH:

Road transport – Cars and lorries equipped with a thermoelectric generators (TEG) would have significant fuel savings (especially with the increasing cost of petrol). In 2009, VW demonstrated this proof of concept. The thermoelectric generator of their prototype car gained about 600W from running on a highway, reducing fuel consumption by 5%

TYPES OF ENERGY HARVESTING MATERIALS

•Pyroelectric materials Change in temperature ↔ electric charge As the temperature of a pyroelectric crystal changes, it generates an electrical charge. Example of pyroelectric EH:

The pyroelectric effect is used in some sensors, but it is still some way from commercial energy harvesting applications


Energy scavenging from wasted ambient energy sources: light, heat, vibrations, RF radiation, etc..

ENERGY HARVESTING SOURCES

courtesy of Zhejiang Solar Panel

courtesy of Perpetua Power Source Technologies

cou

rtes

y o

f b

cp-e

ner

gia

Princeton University

Wireless Sensor and energy harvester

courtesy of SolarBotanic

Source: Georgia Tech

vibrations


Courtesy of Perpetuum

Courtesy of Pavegen

Courtesy of University of Pennsylvania

Courtesy of Christian Croft Courtesy Seiko Watch Corporation

Sustainable Dance Club

Courtesy of SUNY

Ambient vibrations come in a vast variety of forms…

AVAILABLE MECHANICAL SOURCES

POWERLeap system

Patent of University of Michigan


ORDERS OF POWER



1400 kW

20 W

T. Krupenkin and J. A. Taylor, Nature Communications 2011

2.4μW

fabricated at Imperial College London

hybrid transduction mechanism. Hybrid energy harvesters could

power handheld electronics, 18 October 2010, SPIE Newsroom

180μW

1.4μW

fabricated at TIMA - EPFL

60μW

fabricated at IMEC

Macro-scale centimeter-scale MEMS

CONVERSION MECHANISM


TRADITIONAL APPROACH

• In the vast majority of cases the ambient vibrations come in a vast variety of forms.

• The energy distributed over a wide spectrum of frequencies, typically confined in a maximal bandwidth of few thousand of Hz.

A classical transduction mechanism is based on vibrating mechanical bodies (linear systems).

MEMS D

P0Vib.

Output

PZT

Linear System


LINEAR APPROACH

Typ

ical

en

erg

y h

arve

ste

r p

rin

cip

le

MEMS D

P0Vib.

Output

PZT


<

LINEAR APPROACH

… some issues with linear resonant harvesters …

Linear systems exhibit a resonant behaviour (i.e. resonance frequency). Transfer function presents one or more peaks corresponding to the resonance frequencies and thus it is efficient mainly when the incoming energy is abundant in that regions.

Narrow frequency bandwidth: the generator must be designed for specific vibration sources and applications. Require resonance frequency matching with vibrational sources.


Linear and nonlinear Strategies … some issues with linear resonant harvesters …

Linear resonant structures Require frequency matching with sources. Poor performance out of resonance. Difficulties in scaling and tuning at micro/nano scale.

Suitability only with narrow band vibrations (e.g. from

rotating machines).

Frequency band matching issues in MEMS and NEMS

technologies. Wideband vibrations below 500 Hz (about the 90 % of vibrational sources) require a different strategy to efficiently harvest energy

Whishlist for the ‘’perfect’’ vibration harvester: 1) Harvesting energy over a wide frequency band 2) No need for frequency tuning 3) Harvesting energy at low frequency (below 500 Hz)

How to increase efficiency of energy harvester?

LINEAR APPROACH


SOTA - WIDE BAND HARVESTER


Linear and nonlinear Strategies … Nonlinear vibration energy harvesters …

Nonlinearity can be induced by: the geometry of the springs in the device; material nonlinearities or induced stress; mechanical coupling with other fields (magnetic and so on).

m and c are constant terms while

k(z) is a nonlinear function of the displacement z.

U(z) is the nonlinear Duffing Potential. a and b are coefficients depending on both the geometry of the device and the permanent magnets.

NONLINEAR MECHANISM – EXAMPLE 1

MEMS D

P0Vib.

Output

PZT


Prototype 1 and experimental setup

aluminum beam 53mm x 8.5mm

Δ=2mm



Input

System displacement



MICRO-MACHINED DEVICES (SOI TECHNOLOGY) – EXAMPLE 2

o Fabrication (SOI TECHNOLOGY):

• SOI wafer: 15 μm c-Si layer, 450 μm carrier substrate, 2 μm buried oxide

• Front and back side DRIE etching technique

• Fabrication: CNM, Barcelona, Spain



o Fabrication (SOI TECHNOLOGY):

• SOI wafer: 15 μm c-Si layer, 450 μm carrier substrate, 2 μm buried oxide


• Fabrication: CNM, Barcelona, Spain


o Fabrication (PIEZOMUMPs TECHNOLOGY):

• A Silicon On Insulator (SOI) wafer based on 10 μm upper silicon layer and 400 μm thick of substrate with 1 μm of buried oxide has been used


• Fabrication: MEMSCAP

MICRO-MACHINED DEVICES (PIEZOMUMPS TECHNOLOGY) – EXAMPLE 3


Micro-machined devices

o Bistable SOI and PIEZOMUMPs cantilever beam:

• After gluing a magnet, bi-stable behavior is obtained

• Displacement is electrically-measured through strain gauges

MICRO-MACHINED DEVICES (SOI/PIEZOMUMPS TECHNOLOGY)


Experimental Setup MICRO-MACHINED DEVICES (SOI TECHNOLOGY) – EXAMPLE 2


Experimental Setup

Output strain gauge

Permanent magnets stack

MEMS device

32



Results

∆=1.5 mm ∆=1.6 mm ∆=1.7 mm

∆=4.5 mm ∆=2.4 mm ∆=1.8 mm

o Positioning the permanent magnet

@ 0.88 g / σ=20 μN Measures on SOI device



Results o Response @ optimal distance of permanent magnet

@ 0.88 g / σ=20 μN

Maximum voltage≈16mV @ 1g RMS

Measures on PIEZOMUMPs device



A Wireless Sensor Node Powered by NonLinear Energy Harvester


The general architecture of a Vibration Energy Harvesting system …

Vibrational source

Acceleration amplitude

Frequency Spectrum …

TYPICAL EH ARCHITECTURE SCHEMATIZATION


Vibrational source

Coupling mechanical

structure

Linear Nonlinear …






Y

X

System has two stable equilibrium states (S1 and S2), separated by unstable equilibrium state (U).

The device switching between its stable states allows for improving the efficiency of the energy conversion, from mechanic to electric

Fixed-Fixed Beam Linear Beam

The vertical moviment of the mass caused by vibrations creates the strain in the beam. The piezoelectric material convert this strain in a voltage.

Stable

equilibrium

position n°1 Stable

equilibrium

position n°2

Instable

equilibrium

position

Neutral

equilibrium

position

S2

U

S1

LINEAR VS NON LINEAR


Vibrational source

Coupling mechanical

structure


Mechanical-to-electrical conversion

Piezoelectric Electrostatic Electromagnetic …






Vibrational source

Coupling mechanical

structure

Mechanical-to-electrical conversion


Piezoelectric Electrostatic Electromagnetic …

Electrical energy output

“Direct powering” “batteries recharging” ?






DOUBLE PIEZO – SNAP THROUGH BUCKLING HARVESTER

Schematization of the bistable nonlinear harvester

Top view

RF transmitter TI eZ430 – RF2500

10 cm

The DP-STB-NLH Piezoelectric transducers Mide's Volture™ V21bl

PET (PolyEthylene Terephthalate) beam 6 cm x 1 cm x 100 µm

Linear Technology LT3588-1 + input/output storage capacitors


Flexible precompressed PET beam + suitable proof mass implementing the bistable mechanism

Two piezoelectric vibration energy harvesters V21BL (Volture) connected in a parallel configuration

DOUBLE PIEZO – SNAP THROUGH BUCKLING HARVESTER

X

Y

ΔX

ΔY/2

Cantilever

ΔY/2

F

t

Piezoelectric

Proof mass

6 c

m

Piezoelectric

on both faces

Cantilever

6 c

m

3.5

6 c

m 3.5

cm

2

.5 c

m

Max tip-to-tip displacement = 0.46 cm

fixed-fixed PET beam

Inertial mass (3g)

Pre-compression ΔY= 2 mm

Specifications - v21bl Device size (cm): 9.04 x 1.7 x 0.08 Device weight (g): 3.26 Active elements: 1 stack of 2 piezos Piezo wafer size (cm): 3.56 x 1.45 x 0.02


The STB harvester can be modeled as a classical second order mass-damper-spring system, with an additive nonlinear term related to the bistable potential energy function

MECHANICAL BEHAVIOR OF THE STB-NON LINEAR HARVESTER

24

2

1

4

1)( xbxaxU

-10 -8 -6 -4 -2 0 2 4 6 8 10-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

Displacement x of the central mass along X-axis from initial position [mm]

Ela

stic

Po

ten

tial E

ne

rgy

U(x

) [N

*mm

]

)(3 tFxbaxxdxm


STATIC CHARACTERIZATION OF THE BEAM BEHAVIOR

Goal: measurement of the minimum acceleration required to implement the switching mechanism between the two stable states of the device. Methodology: Experiments consisting of loading the pre-compressed beam with reference masses (forces) until switching occurs .

Acceleration required to make the beam switch between its stable states, with different proof masses loading the beam. The continuous lines denote interpolation models.

acceleration values are compatible with standard sources

14 16 18 20 22 24 261

2

3

4

5

6

7

Distance between stable equilibrium positions DX [mm]

Acce

lera

tio

n [

m/s

2]

mproof

=6g

mproof

=12g

mproof

=18g

1 2 3Pre-compression DY [mm]


-10 -5 0 5 10-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

0.04

Displacement along X-axis from stable states [mm]

Re

actio

n fo

rce

alo

ng

X-a

xis

[m

N]

Observed

Predicted

-10 -5 0 5 10-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05


Ela

stic P

ote

ntia

l E

ne

rgy U

(x)

[N*m

m]

STATIC CHARACTERIZATION OF THE BEAM BEHAVIOR

Reconstruction of the reaction force )(x

The pre-compressed beam was stressed by a controlled force applied orthogonally to the beam center. A load cell (Transducer Techniques GSO-10) was used to independently measure the force.

2

2

real

predreal

F

FFJ

2 / 4U b aD

To fit the observed behavior, a Nelder Mead optimization algorithm was implemented through a dedicated Matlab script exploiting the following minimization index:

Parameters estimated (in case of pre-compression ∆Y of 3 mm ): a = 1.039e-4 kg/m2s2, b= 0.0098 kg/s2

24

2

1

4

1)( xbxaxU


4 6 8 10 12 14 162

4

6

8

10

12

14

16

18

frequency [Hz]

RM

S A

ccele

ration

[m

/s2]

Dynamic mechanical characterization of the DP-NLH device in case of a beam pre-compression of 3 mm and a proof mass of 6g.

The envisaged broadband operation of the proposed bistable architecture emerges via the possibility of inducing switching events by slightly supra-threshold acceleration values for the entire frequency range of interest.

THE DYNAMIC MECHANICAL CHARACTERIZATION

Goal: estimation of the minimum acceleration (vs stimulus frequency) able to make the device switch between its stable states. Methodology: the beam was subjected to several repeated cycles of a periodic sine mechanical stimulation in the range [4 - 15] Hz applied via a standard shaker. A reference laser system (Baumer OADM 12U6430/S35A) was used to obtain an independent quantification of the beam switching while the analog accelerometer (Freescale Semiconductor MMA7361L) was used to independently measure the acceleration applied.


ELECTRICAL CHARACTERIZATION OF THE NONLINEAR HARVESTER

Goal: Investigation of the electrical performances of the DP-STB device in terms of electrical power generated for different values of acceleration, pre-compression, proof mass and resistive load. Methodology: the device was subjected to several repeated cycles of a periodic sine mechanical stimulation in the range [4 - 10] Hz applied via a standard shaker .

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-6

-4

-2

0

2

4

6

8

time [s]

Vp

iezo [V

]

-4.18

-2.78

-1.39

0

1.39

2.78

4.18

5.57

Vacc [V

]

Piezoelectrics

Accelerometer

aRMS

= 9.81 m/s2

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-10

-5

0

5

10

15

time [s]V

pie

zo [V

]

-4.12

-2.06

0

2.06

4.12

6.18

Vaccel [

V]

Piezoelectrics

Accelerometer

aRMS

= 11.24 m/s2

f= 4 Hz – Rload = 1MΩ

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-30

-20

-10

0

10

20

30

Vpie

zo [

V]

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-6

-4

-2

0

2

4

6

Vacc [

V]

time [s]

Piezoelectrics

Accelerometer

aRMS

=16.81 m/s2

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-60

-40

-20

0

20

40

60

time [s]

Vpie

zo [V

]

-10.35

-6.90

-3.45

0

3.45

6.90

10.35

Vaccel [

V]

Piezoelectrics

Accelerometer

aRMS

= 28.66 m/s2

f= 10 Hz – Rload = 1MΩ

102

103

104

105

0

50

100

150

200

250

300

350

Load resistance []

Po

we

r [

W]

f=4Hz

f=5Hz

f=8Hz

f=10Hz

aRMS

= 16.81 m/s2

aRMS

= 12.11 m/s2

aRMS

= 11.43 m/s2

aRMS

= 9.81 m/s2


Frequency [Hz] Power [µW]

4 284.8

5 296.3

8 309.4

10 313

Electrical power produced by the DP-NLH device as been evaluated as

R/V 2

RMS

where VRMS is the RMS voltage measured across the load R (0.1 – 100 kΩ)

ELECTRICAL CHARACTERIZATION OF THE NONLINEAR HARVESTER

aRMS = 16.81 m/s2 R = 5 kΩ

frequency broad band operation 102

103

104

105

0

50

100

150

200

250

300

350

Load resistance []

Po

we

r [

W]

f=4Hz

f=5Hz

f=8Hz

f=10Hz

aRMS

= 16.81 m/s2

aRMS

= 12.11 m/s2

aRMS

= 11.43 m/s2

aRMS

= 9.81 m/s2


Batteries or capacitors

LTC3588-1 Piezoelectric Energy Harvesting Power Supply

Up to 100mA of Output Current Selectable Output Voltages of 1.8V, 2.5V, 3.3V, 3.6V

ENERGY STORAGE AND POWER MANAGEMENT


Energy source Energy Harvester Storage

Load

Load to supply

LTC3588-1 supercapacitor

The LTC3588-1 has an internal full-wave bridge rectifier accessible via the differential PZ1 and PZ2 inputs that rectifies AC inputs such as those from a piezoelectric element. The rectified output is stored on a capacitor at the VIN pin and can be used as an energy reservoir for the buck converter.



NLH + LTC3588-1

Investigation of the capability of the NLH to generate power to supply electronic.

The device was subjected to several repeated cycles of a periodic sine mechanical stimulation at 10Hz.

The time for first activation of the output, the time required for consecutive activations and the time assuring a high Vo, have been evaluated.

Vc VO

Supercapacitors

CSTORAGE = 47 µF aRMS =9.81 m/s2

Rload = 100 kΩ

t’ tonVo tonPGOOD t’

CSTORAGE = 94 µF aRMS =9.81 m/s2

Rload = 100 kΩ

Δt

PGOOD enable pin


LOAD

[Ω]

t’

[s]

∆t

[s]

tonPGOOD

[s]

tonVo [s]

supercapacitors

47µF

560 38.19 13.90 0.01 0.06

1.1k 38.80 14.30 0.02 0.1

2.2k 39.50 14.07 0.02 0.2

5k 39.37 15.00 0.1 0.51

10k 39.00 13.90 0.19 0.94

100k 39.79 14.95 2.25 9.25

supercapacitors

94µF

560 61.99 21.87 0.03 0.07

1.1k 79.31 29.59 0.05 0.13

2.2k 78.49 30.57 0.09 0.26

5k 81.21 31.72 0.22 0.64

10k 72.09 26.30 0.44 1.27

100k 70.87 26.2 5.3 12.52

LOAD

[Ω]

t’

[s]

∆t

[s]

tonPGOOD

[s]

tonVo [s]

supercapacitors

47µF

560 23.68 8.58 0.02 0.07

1.1k 25.20 7.97 0.02 0.11

2.2k 22.85 8.32 0.04 0.23

5k 24.59 8.62 0.09 0.52

10k 24.90 8.41 0.19 0.94

100k 25.19 8.89 2.61 9.98

supercapacitors

94µF

560 43.09 15.27 0.02 0.07

1.1k 50.49 17.16 0.04 0.14

2.2k 52.40 18.11 0.09 0.28

5k 50.17 17.28 0.22 0.61

10k 49.40 17.86 0.44 1.21

100k 48.72 17.54 5.85 12.97

aRMS = 9.81 m/s2 fs=10Hz aRMS = 11.43 m/s2 fs=10Hz

NLH + LTC3588-1


102

103

104

10510

15

20

25

30

35

Load resistance []

Dt [s

]

aRMS

=9.81 m/s2

aRMS

=11.34 m/s2

aRMS

=12.11 m/s2

102

103

104

1050

1

2

3

4

5

6

7

Load resistance []

t onP

GO

OD

[s]

aRMS

=9.81 m/s2

aRMS

=11.43 m/s2

aRMS

=12.11 m/s2

102

103

104

10515

20

25

30

35

40

Load resistance []

t' [s

]

aRMS

=9.81 m/s2

aRMS

=11.43 m/s2

aRMS

=12.11 m/s2

102

103

104

1055

10

15

Load resistance []D

t [s

]

aRMS

=9.81 m/s2

aRMS

=11.43 m/s2

aRMS

=12.11 m/s2

102

103

104

10535

40

45

50

55

60

65

70

75

80

85

Load resistance []

t' [s

]

aRMS

=9.81 m/s2

aRMS

=11.43 m/s2

aRMS

=12.11 m/s2

102

103

104

1050

0.5

1

1.5

2

2.5

3

3.5

Load resistance []

t onP

GO

OD

[s]

aRMS

=9.81 m/s2

aRMS

=11.43 m/s2

aRMS

=12.11 m/s2

CSTORAGE = 47 µF CSTORAGE = 47 µF

CSTORAGE = 47 µF

CSTORAGE = 94 µF CSTORAGE = 94 µF CSTORAGE = 94 µF

DP-STB + LTC3588-1


NLH + LTC3588-1 + RF-TX

aRMS

[m/s2]

t’

[s]

∆t

[s]

tonPGOOD

[s]

ton-PIN6

[s]

tPGOOD

-PIN6

[s]

supercapacitor

47µF

9.81 28.82 11.57 0.01 0.03 0.005

11.43 18.95 5.96 0.02 0.02 0.005

12.11 11.99 5.12 0.02 0.03 0.005

supercapacitor

94µF

9.81 55.12 21.39 0.03 0.03 0.01

11.43 46.30 15.04 0.05 0.02 0.005

12.11 29.06 9.25 0.09 0.02 0.01

CC2500 Pushbutton

18 Accessible Pins

Chip Antenna

two LEDs

MSP430F2274

Producer Texas Instruments

Max Frequency 16MHz

Communication USB/2.4GHz

Power supply 1.83.6V

Board Power Consumption (max values)

Only processor Active mode 390µA Stanby mode 1.4µA

RF Transceiver RX mode 18.8mA TX mode 21.2mA

PIN6 is a digital output pin on the RF receiver (RX)

Goal: Investigation of the capability of the DP-STB

device to power a RF - TX


0 20 40 60 80 100 120

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

time [s]

Vo

lta

ge

[V

]

acceleration

VC

Enable

RX digital output

-55.82

-44.66

-33.50

0

33.50

44.66

55.82

acce

lera

tio

n [

m/s

2]

t' Dt Dt

77 77.05 77.1 77.15

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

time [s]

Vo

lta

ge

[V

]

acceleration

VC

Enable

RX digital output

-55.82

-44.66

-33.50

0

33.50

44.66

55.82

acce

lera

tio

n [

m/s

2]

0 10 20 30 40 50 60 70

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

time [s]

Vo

lta

ge

[V

]

-81.35

-65.09

-48.81

0

48.81

65.09

81.35

acce

lera

tio

n [

m/s

2]

acceleration

VC

Enable

RX digital output

Dt DtDtDtt'

Signals have been acquired by a Lecroy 6050A WaveRunner digital oscilloscope

The Enable pin, is logic high when the output voltage is above 92% of the target value (set to 3.3 V).

The node is able to scavenge energy from wideband vibrations to transmit data by the SimpliciTI® network protocol @ 2.4 GHz.

NLH + LTC3588-1 + RF-TX


Conclusions A batteryless wireless node powered by a nonlinear bistable energy harvester has been discussed. The node is able to scavenge energy from wideband vibrations to transmit data @ 2.4 GHz. Results obtained encourage the use of proposed nonlinear harvesters to power wireless sensor nodes.

Future works

• Characterization of the behavior of the device with a noisy input stimulation • Development of an analytical model including the mechanical to electrical conversion.

ACKNOWLEDGMENT The authors gratefully acknowledge support from the US Office of Naval Research (Global), and the US Army International Technology Center (USAITC).

Smart&Authonomous Sensing Systems @SensorLab

DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

InkJet Printed– Snap Through Buckling Harvester

MassIJP STB HarvesterClamping System

Substrate IJP electrodes PZT Clamping System

The STB beam is implemented via a PET (PolyEthylene Terephthalate) substrate

Development of Low Cost Printed Devices for Energy Harvesting from Environmental Vibrations (CSP06N1EJEPC30), 2012-2013 DEPARTMENT OF THE ARMY ARMY MATERIAL COMMAND

RESEARCH, DEVELOPMENT AND ENGINEERING COMMAND INTERNATIONAL TECHNOLOGY CENTER-ATLANTIC UNIT (ITC-AC)


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

The proposed approach: Snap Through Buckling Harvester

Main challenges: •The low cost mechanical structure implementing the non linear switching mechanism ; •The technology to realize electrodes, sensors, readout systems and functional layers; •The mechanic-electric conversion.

Solution: a two-end clamped PET beam exploiting “snap-through buckling” approach, low cost COTS devices and direct printing methodologies.

X

Y

ΔX

ΔY/2

Stable

state

Stable

state

ΔY/2

F

t Proof mass

Z


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

The STB harvester can be modeled as a classical second order mass-damper-spring system, with an additive nonlinear term related to the bistable potential energy function

Mechanical Behavior of the STB-Non Linear Harvester

24

2

1

4

1)( xbxaxU

-10 -8 -6 -4 -2 0 2 4 6 8 10-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05


Ela

stic

Po

ten

tial E

ne

rgy

U(x

) [N

*mm

]


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Static characterization of the beam behavior

Goal: measurement of the minimum acceleration required to implement the switching mechanism between the two stable states of the device. Methodology: Experiments consisting of loading the pre-compressed beam with reference masses (force) until switching occurs .

Acceleration required to make the beam switch between its stable states, with different proof masses loading the beam. The continuous lines denote interpolation models.

acceleration values are compatible with standard sources


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

1

MN

MX

X

Y

Z

Forza_2

-.149E-06.780E-03

.001561.002341

.003121.003902

.004682.005463

.006243.007135

NODAL SOLUTION

STEP=1

SUB =32

TIME=1

UX (AVG)

RSYS=0

DMX =.007135

SMN =-.149E-06

SMX =.007135

S2

S1

Input: External force, Fest

Output: Displacement ΔX

1

MNMX

X

Y

Z

Forza

-.908E-08.657E-03

.001314.001972

.002629.003286

.003943.0046

.005258.006009

NODAL SOLUTION

STEP=5

SUB =11

TIME=5

UX (AVG)

RSYS=0

DMX =.006009

SMN =-.908E-08

SMX =.006009 S1

S2

Fest<f2-1 the beam

doesn’t switch

FEM (Finite Element Method) Analysis in Ansys®

1

MN

MX

X

Y

Z

Forza_2

-.00799-.007116

-.006243-.005369

-.004495-.003621

-.002747-.001873

-.999E-03.434E-07

NODAL SOLUTION

STEP=1

SUB =15

TIME=1

UX (AVG)

RSYS=0

DMX =.00799

SMN =-.00799

SMX =.434E-07 S1

S2

1

MN

MX

X

Y

Z

Forza_2

-.149E-06.780E-03

.001561.002341

.003121.003902

.004682.005463

.006243.007135

NODAL SOLUTION

STEP=1

SUB =32

TIME=1

UX (AVG)

RSYS=0

DMX =.007135

SMN =-.149E-06

SMX =.007135

S2

S1

Fest>f2-1 the beam

switches from the state

S2 to the state S1

S1 and S2 are the stable equilibrium states estimated when the force is null

f1-2 e f2-1 are the static forces allowing the commutation between two stable states.


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly


To improve performances of FEM predictions the following correction model has been estimated

FFEMF bFaF

where F denotes the force required to switch the beam estimated by model starting from the simulated values, and aF = 0.8 and bF = 0.008 N are fitting parameters obtained by applying a least mean squares minimization algorithm.

1 2 325

30

35

40

45

50

55

Pre-compression DY [mm]

Re

actio

n F

orc

e [

mN

]

FEM

Observed

Estimated

Static force required to make the beam switch between its stable states. Comparison between observations, FEM simulations, and estimations obtained by model for different pre-compression values, are shown.


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly


The model adopted to describe the relationship between the minimum acceleration am enabling the beam switching, and ∆X as a function of the proof mass m, is

DDD mmXXmXma iiimi

22

where:

mi (i=6 g, 12 g, 18 g) represents the proof mass

= 6.7639e-4 m4·kg6/s2

= -0.0244 m4·kg3/s2

= 0.2683 m4/s2

= 0.0107 m·kg6/s2

= -0.3824 m·kg3/s2

= 4.1885 m/s2

fitting parameters estimated by applying the Nelder–Mead nonlinear simplex optimization algorithm with the following functional J

g

g

gi

i

pred

m

real

m

N

i

N

aaJ

ii

183

122

61:

3

1

2


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Investigations of dynamic performance of the IJP-STB harvester

Goal: estimation of the minimum acceleration (vs stimulus frequency) able to make the device switch between its stable states. Methodology: the beam was subjected to several repeated cycles of a periodic sine mechanical stimulation in the range [4 - 20] Hz applied via a standard shaker. A reference laser system (Baumer OADM 12U6430/S35A) was used to obtain an independent quantification of the beam switching while the analog accelerometer (Freescale Semiconductor MMA7361L) was used to independently measure the acceleration applied.

0 2 4 6 8 10 12 14 16 18 200

5

10

15

20

25

30

35

40

Frequency [Hz]

Acce

lera

tio

n [

m/s

2]

DY=1mm

DY=3mm

Minimum acceleration assuring the switching mechanism as a function of the stimulus frequency and the beam pre-compression. A proof mass of 6 g was used to load the beam.


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Investigations of dynamic performance of the IJP-STB harvester

0 0.5 1 1.5 2 2.5 3 3.5 4-15.9

-7.95

0

7.95

15.9

time [s]

Dis

pla

ce

me

nt

[mm

]

0 0,5 1 1,5 2 2,5 3 3,5 4-19.05

-9.52

0

9.52

19.05

time [s]

Acce

lera

tio

n [

m/s

2]

laser

accelerometer

0 1 2 3 4

-12.9

0

12.9

time [s]

Dis

pla

ce

me

nt

[mm

]

0 1 2 3 4-47.62

-23.81

0

23.81

47.62

time [s]

Acce

lera

tio

n [

m/s

2]

laser

accelerometer

ΔY= 1 mm ΔY= 3 mm

laser

accelerometer

PSD of the laser output signal

Example of time series of signals output in case of sinusoidal solicitation at 6Hz with the strength close to the minimum value assuring the beam switching between its stable states


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Fitting observed behavior by the model

24

2

1

4

1)( xbxaxU

Experimental set-up for the estimation of the potential form U(x).

The applied force was independently measured by the load cell (Transducer Techniques GSO-10)

In order to fit the observed behaviors by model (*), a Nelder Mead optimization algorithm was implemented through a dedicated Matlab script exploiting the following minimization index:

(*)

where =b-c

2

2

2

2

real

predreal

real

predreal

F

FF

x

xxJ

xreal and xpred refer to the measured and predicted displacement of the bistable device Freal and Fpred refer to the measured and predicted force


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

-8 -6 -4 -2 0 2 4 6 8-40

-30

-20

-10

0

10

20

30

40


Re

actio

n f

orc

e a

lon

g X

-axis

[m

N]

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-10

-8

-6

-4

-2

0

2

4

6

8

10

time [s]

Dis

pla

ce

me

nt

x a

lon

g X

-axis

[m

m]

Measured displacement

Predicted displacement

-10 -8 -6 -4 -2 0 2 4 6 8 10-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05


Ela

stic P

ote

ntia

l E

ne

rgy U

(x)

[N*m

m]

-15 -12 -9 -6 -3 0 3 6 9 12 15-100

-50

0

50

100


Reaction forc

e a

long X

-axis

[m

N]

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-15

-10

-5

0

5

10

15

time [s]

Dis

pla

cem

ent x a

long X

-axis

[m

m]

Measured displacement

Predicted displacement

-15 -10 -5 0 5 10 15-1.5

-1

-0.5

0

0.5


Ela

stic P

ote

ntial E

nerg

y U

(x)

[N*m

m]

ΔY= 1 mm

ΔY= 3 mm

Estimated parameters: a = 2.567e-4 kg/m2s2, b=0.017, = -8.462 kg/s2 and d=1.0e-4 kg/s

Estimated parameters: a=1.893e-4 kg/m2s2, b=0.031, = -8.742 kg/s2 and d=1.0e-3 kg/s


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Printed Electronics: Inkjet Printed Sensors

Printed electronics is a set of printing methods

used to create electrically functional devices. Paper has been often proposed to be used as substrate but due the rough surface and high humidity absorption other materials such as plastic, ceramics and silicon has been applied more widely. Several printing processes have been piloted and printing preferably utilizes common printing equipment in the graphics arts industry

Printed Electronics

Printed Sensors

Inkjet Wearable electronics (Active clothing)

Smart Labels (RFID+sensors)

Disposable devices (biomedical) …

Low Costs/Low Performances

Flexible substrates


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Review of Printing technologies in pills…

Technology Advantages Drawbacks

Screen printing several materials masks low resolution time consuming high cost production

Desktop Inkjet printers good resolution low cost system low cost production

restricted number of conductive materials

Professional inkjet systems

high resolution several materials Low cost production

high cost system

Mixed Screen & Inkjet printing

good resolution several materials

Mask time consuming high cost


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Electronics Engineering

Chemistry


Physics

MEMS & NEMS Technologies

Inks

Printing Systems

Substrates

C

H

A

L

L

E

N

G

E

S

Before entering the market various technological improvements are still needed.


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly


Everyday desktop printer (ie Epson) Dimatix DMP 2800

www.dimatix.com

Microdrop inkjet system www.microdrop.de

Litrex M-Series inkjet system www.litrex.com

Printing systems designed

or optimized for the application

Precision and accuracy Throughput / speed and

productivity Maintenance and

reliability Electronic fluids

formulated to meet application standards

Ink jet print engine engineered for the

application Drop volume, velocity,

and placement control Robust and resistant to

electronic fluids High and precise drop

throw rate Wide range of substrates

and surface properties


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Precision and accuracy

Throughput / speed and productivity

Maintenance and reliability

Metalon JS-015 (black)

product by Novacentrix

PET Substrates


EPSON® inkjet printer


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly


PBH1-1

PBH1-2

Printed Bistable Harvester

A set of parallel and InterDigiTed (IDT) electrodes with different dimensions has been designed and realized to test the proposed technology


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

1 c

m

10 cm

Sub

stra

te

IDT

elec

tro

des

Act

ive

Mat

eria

l P

ZT


A PZT layer has been screen printed to convert strains due to the beam switches (induced by external vibrations) between its two stable states into an output voltage.


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

PZT Deposition and poling (Department of Information Engineering (DII) University of Breascia)

Material Depositated

Deposition technology

Thickness Sintering temperature

Poling

IDT electrodes

Piezokeramica APC 856

Screen Printing

50µm

100°C for

10 minutes

100V 130°C

(10 min)

Parallel electrodes

Piezokeramica APC 856

Screen Printing

50µm 100°C for

10 minutes

100V 130°C

(10 min)



DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Layout

IDT electrodes realized by inkjet printing

PZT layer



DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Electrical Behavior of the IJP - STB Harvester

Goal: characterization of the electrical performances of the inkjet printed snap through buckling harvester. Methodology: the beam was subjected to several repeated cycles of a periodic sine mechanical stimulation in the range [4 - 20] Hz applied via a standard shaker. A reference proof mass is placed in the middle of the beam in order to reduce the required acceleration to make the device switching between its stable states. A reference laser system (Baumer OADM 12U6430/S35A) was used to obtain an independent quantification of the beam switching while the analog accelerometer (Freescale Semiconductor MMA7361L) was used to independently measure the acceleration applied.

proof mass

IJP-STB harvester


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Electrical Behavior of the IJP - STB Harvester Examples of the experimental behavior of the device

ΔY=1 mm and Accmax=28.9 m/s2 @6Hz

0 1 2 3 4 5-96.8

-72.6

-48.4

-24.2

0

24.2

48.4

time (s)

Acce

lera

tio

n (

m/s

2)

Accelerometer

STB Harvester

-0.5

0

0.5

1

1.5

2

2.5

Vo

lta

ge

(V

)

0 5 10 15 20 25 30 35 40-95

-80

-60

-50

Frequency (Hz)

Po

we

r/fr

eq

ue

ncy (

dB

/Hz)

0 5 10 15 20 25 30 35 40-95

-80

-60

-40

-20

Frequency (Hz)

Po

we

r/fr

eq

ue

ncy (

dB

/Hz)

Accelerometer

STB Harvester


0 1 2 3 4 5-116.95

-93.05

-69.15

-47.8

-23.9

0

23.9

47.8

69.15

time (s)

Accele

ration

(m

/s2)

-1

-0.5

0

0.5

1

1.5

2

2.5

3V

oltag

e (

V)

Accelerometer

STB Harvester

5 10 15 20 25 30 35 40

-80

-60

-40

-20

Frequency (Hz)

Pow

er/

freq

ue

ncy (

dB

/Hz)

0 5 10 15 20 25 30 35 40

-100

-80

-60

-40

Frequency (Hz)

Pow

er/

freq

ue

ncy (

dB

/Hz)

Accelerometer

STB Harvester


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Electrical Behavior of the IJP - STB Harvester Examples of the experimental behavior of the device


0 1 2 3 4 5

-125.3

-77.7

-29.5

-17.5

0

17.5

29.541.4

65.2

time (s)

Accele

ration

(m

/s2)

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3

Voltag

e (

V)

Accelerometer

STB Harvester

5 10 15 20 25 30 35 40-80

-60

-40

-20

Frequency (Hz)

Po

we

r/fr

eq

ue

ncy (

dB

/Hz)

5 10 15 20 25 30 35 40-80

-60

-40

-20

Frequency (Hz)

Po

we

r/fr

eq

ue

ncy (

dB

/Hz)

Accelerometer

STB Harvester

0 1 2 3 4 5

-125.7

-64.7

-40.9

-17.1

0

17.1

40.9

64.7

time (s)

Accele

ration

(m

/s2)

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3V

oltag

e (

V)

Accelerometer

STB Harvester

0 5 10 15 20 25 30 35 40-80

-60

-40

-20

Frequency (Hz)

Po

we

r/fr

eq

ue

ncy (

dB

/Hz)

0 5 10 15 20 25 30 35 40-80

-60

-40

-20

Frequency (Hz)

Po

we

r/fr

eq

ue

ncy (

dB

/Hz)

Accelerometer

STB Harvester



DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.00

0.005

0.01

0.015

0.02

0.025

AccRMS

[m/s2]

VR

MS

norm

[V

]

0.0 7.9 15.9 23.9 31.9 36.6 40.1 43.6 51.2

Accmax

[m/s2]

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.00

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

AccRMS

[m/s2]

VA

v P

ea

k [V

]

0.0 7.9 15.9 23.9 31.9 36.6 40.1 43.6 51.2

Accmax

[m/s2]

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.00

0.02

0.04

0.06

0.08

0.1

0.12

0.14

AccRMS

[m/s2]

VR

MS

norm

[V

]

0.0 8.5 16.9 25.4 33.9 36.4 43.6 46.8 49.9 53.4 59.3

Accmax

[m/s2]

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.00

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

AccRMS

[m/s2]

VA

V P

eak

[V]

0 8.5 16.9 25.4 33.9 36.4 43.6 46.8 49.9 53.4 59.3

Accmax

[m/s2]

ΔY= 1 mm

ΔY= 3 mm

norm

RMSVAvPeakV and values as a function of the accelerations applied to the device for the two values of

the pre-compression


6 Hz 8 Hz

10 Hz

12 Hz 14 Hz

6 Hz 8 Hz 10 Hz

12 Hz


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly


RV PeakAV /2

PeakAVV

An evaluation of the electrical power produced by the STB device has been performed by

where is the average of the of the piezoelectric output voltage peaks measured across the load R=1MΩ

Powers in the order of 102 nW have been experimentally estimated


DIE

EI –

Un

ive

rsit

y o

f C

atan

ia, I

taly

Nonlinear Energy Harvesting from vibrations - DIEES - · PDF file ·...

Documents

Transcript of Nonlinear Energy Harvesting from vibrations - DIEES - · PDF file ·...