Energy Harvesting for IoT

ENERGY HARVESTERS POWERING THE IOT

MT5009 Analyzing High-Tech Opportunities

National University of Singapore

Rhee Min Woo A0132465J Douglas Gong A0034283L Karen Tan A0132409M Thomas Chan A0133076L Wang Niyou A0039878H Tan Geok Bin A0110245Y

•  Introduction to IoT And Sensor

•  Energy Harvesters (EH)

•  Important Dimensions Of Performance & Cost For EH

•  EH Technology Drivers, Challenges & Roadmap

•  EH Applications For Entrepreneurial Opportunities

•  Conclusion

AGENDA

IoT - A SMART WORLD of Sensors

EH DEVICES SUSTAINING POWER IN TEMPERATURE SENSORS, AIR QUALITY SENSORS, USED IN HEATING, VENTILATION, AND AIR CONDITIONING (HVAC) ,LIGHTING APPLICATIONS, HEALTHCARE

SMART WIRELESS SOLUTIONS

Source: https://www.enocean-alliance.org

SMART OFFICE SMART HOSPITAL

SMART HOME SMART FACTORY others…retail buildings, schools, streets, amusement parks, malls, sports complex, hotels, airports, transportations etc

TRILLION SENSORS in IoT

SHRINKING SENSORS COST WITH REDUCED SENSOR SIZE

>~ $300

<<$1

2010 2015 2020


•  Energy Harvesters (EH) •  Important Dimensions Of Performance & Cost For EH



•  Conclusion

AGENDA

WHAT IS ENERGY HARVESTING? Energy harvesting is the process of capturing ambient energy and storing as electricity. 4 main ambient energy sources present in our environment: •  Mechanical energy (vibrations, deformations) •  Thermal energy (temperature gradients or

variations), •  RF energy (radio transmissions) •  Solar energy (sun) It is FREE energy.

AUTONOMOUS WIRELESS SENSOR NETWORKS & NEEDS

Energy Harvesting

BATTERY OPERATED WSN VS ENERGY HARVESTED NODE

Source: http://www1.i2r.a-star.edu.sg/~hptan/publications/icc2010_wsnheap.pdf

1 year

infinite

time

MEGA-SCALE MESO-SCALE MICRO-SCALE •  Large scale energy production •  Harvested power density in the

range of MW/cm3

•  Large scale power devices •  Power density in the range of W/cm3

•  MEMS-NEMS Scale, for Ultra low

power electronics such as WSN •  in IOT •  Power density range of μW/cm3

ENERGY HARVESTING TAXONOMY

NOW NOW MINIATURIZATION in the IOT Era

Vibrations EH mounted on industrial motor

POWER CONSUMPTION FOR VARIOUS APPLICATIONS

Zigbee

HOW MUCH MICRO-SCALE EH POWER CAN BE TAPPED ?

Source: Holst Centre

MEMS VIBRATION ENERGY HARVESTING Power ~ 100uW /cm2

Source: Development of piezoelectric microcantilever flow sensor with wind-driven energy harvesting capability Huicong Liu, Songsong Zhang, Ramprakash Kathiresan, Takeshi Kobayashi, and Chengkuo Lee

PIEZOELECTRIC

10 × 8 × 0.45mm3

3D VIBRATION-DRIVEN ELECTROMAGNETIC

MEMS ROTARY COMB ELECTROSTATIC

THERMOELECTRIC ENERGY HARVESTING CMOS MEMS-Based Thermoelectric Energy Harvester ~14uW/cm2 @ 5K

Source: Jin Xie, Chengkuo Lee, Ming-Fang Wang, and Hanhua Fang, Seal and encapsulate cavities for CMOS MEMS thermoelectric power generators, J. Vacuum Sci. & Technol. B, vol. 29, no. 2, pp. 021401, Mar 2011

PHOTOVOLTAIC ENERGY HARVESTING Solar Power Energy Harvester In MEMS Wireless Intra-ocular Pressure Sensor ~ 10mW/cm2

RF ENERGY HARVESTERS RF Energy Harvesting Converts Radio Waves Into DC Power ~ 0.1uW/cm2

ENERGY HARVESTERS TECHNOLOGIES Thermal 100uW/cm2 ; Vibration 300uW/cm2; PV 15mW/cm2 ; RF 10uW/cm2

Reduce the power consumption per transducer below 100 nW, while meeting resolution, bandwidth and measurement range constraints

SENSORS ROADMAP – POWER REDUCTION IN IoT CURRENT SOA EH TECHNOLOGIES (10uW to 15mW) MEETING DEMAND OF IoT SENSORS

Scaling in Piezoelectric Vibrational EH

Reference : APEC2011 MicroGen

PRICE REDUCTION WITH REDUCED EH SIZES

Miniaturization driven by MEMs technology reduces cost $300~900 à less than $50 (2014). In IoT, < $1 integrated micro-EH






•  Conclusion

AGENDA

IMPORTANT DIMENSIONS OF PERFORMANCE & COST FOR ENERGY HARVESTERS

Performance -  Effective Energy Source (Motion/Light/Temperature) -  Power output (μW, mW, Voltage x current) -  Conversion efficiency (%) -  Life time-reliability (hr/month/year)

Cost -  MEMS / Wafer scale 6,8,12,18 (inch) -  MEMS / Device Miniaturization -  Device Packaging &Test ($) -  Process Platform, yields (%)

IMPORTANT DIMENSIONS OF PERFORMANCE & COST for Energy Harvesters – Energy Sources

Reference : APEC2012

Reference : ECTC2014

IMPORTANT DIMENSIONS OF PERFORMANCE for Energy Harvesters – Power Generation vs Vibration G in VEH – Power Generation vs Device Size in VEH

Reference : APEC2011 MicroGen

P ∞ A – Power Generation increased by size (A) and intensity of external energy source (G)

IMPORTANT DIMENSIONS OF PERFORMANCE FOR ENERGY HARVESTERS – Power Generation vs Temperature difference/ Size in TEG

Reference :

P ∞ ΔT P ∞ A

Larger

– Power Generation Temperature difference (ΔT) and device size (A)

IMPORTANT DIMENSIONS OF PERFORMANCE for Energy Harvesters – Performance (ZT / Power density) of Thermoelectric materials for TEG

Reference : Northwestern University Reference : Nextreme

– TEG materials for Higher ZT is continuously developed – TEG with thin film technology showed significantly improved power density

Seebeck coefficient S, thermal conductivity λ,　and electrical conductivity σ, and temperature T.

IMPORTANT DIMENSIONS OF PERFORMANCE for Energy Harvesters – Power Generation vs Operational Life Expectancy

– Battery continuously decrease the power density as years goes by (5yrs max) – EH shows stable power supply over the years, normal target is > 20yrs






•  Conclusion

AGENDA

•  Proliferation of autonomous sensing and communication systems •  Advanced infrastructure, mater ials and design tools

(micromachining, functional thin films, wafer stacking) •  Techniques for integration with ultra-low power electronic circuits and sensors • Better understanding of energy efficiency limits • Availability of hybrid harvesters •  Going beyond CMOS disruptive energy efficient technologies

and devices towards Nanotechnology (nanowire electronics, NW, NCTs, carbon and graphene ,spine electronics, memristive devices, photonics, synthetic photovoltaic cells etc)

TECHNLOGY DRIVERS & CHALLENGES FOR ENERGY HARVESTERS

MEMS TO NEMS TECHNOLOGY ROADMAP THERMOELECTRIC EH POWER DENSITY 0.5mW/K2 to 4.5mW/K2

UNDERSTANDING EFFICIENCY LIMIT FOR THERMOELECTRIC ENERGY HARVESTERS CARNOT EFFICIENCY FOR DIFFERENT THERMO MATERIALS

TOWARDS NANOTECHNOLOGY ROADMAP PHOTOVOLTAIC ENERGY HARVESTER EFFICIENCY (@40% in 2023 > SQ LIMIT 33.7%)

PHOTOVOLTAIC MATERIALS FOR OPV DEVELOPMENT

PHOTOVOLTAIC EH EFFICIENCY LIMITED BY SHOCKLEY QUEISSER (SQ 33.7%)

30%

15%

2013 2018 2023

33.7% SQ Limit

CIGS 20%

CdTe 16%

amoSi

13%

Polymer 8%

DSSC(solid) 7%

DSSC(liquid) 13%

STATE OF ART PV EH Efficiency

Single crystal Si solar cell - costly

KEY RESEARCHER Challenge to

Exceed the SQ Limit at lower cost

in IoT.

MEMS TO NEMS TECHNOLOGY ROADMAP VIBRATION ENERGY HARVESTERS Power density 1.5mw/cm2 to 10mw/cm2

HYBRID VIBRATION ENERGY HARVESTORS PROTOTYPE Development of combo Piezoelectric & EM EH prototype @ NUS MEMS energy harvester dept - Increase power density from 0.1mw/cm2 to 5mw/cm2






•  Conclusion

AGENDA

GLOBAL MARKET FROM 2014-2024

Economically feasible technologies:

Thermoelectric and Piezo EH

Early adopters stage: Entrepreneurial opportunities

starts now. Get ready for launch by 2017!

WHY THE THERMOELECTRIC AND PIEZOELECTRIC EH SEGMENTS?

� Thermoelectric have no moving parts

� Piezoelectric promises high efficiency (up to 90% with further research)

� More affordable

� Superlative energy density

CHALLENGES

1)  Energy capacity: still limited to some low-powered devices

2)  Cost: an energy harvesting device is and will remain for a while considerably more expensive than batteries or the main grid (batteries are typically US$0.30 to US$1)

3)  Size: must be small to enable mobility <1cm3; and lightweight.

4)  Integration: between different involved parts. Using energy harvesting would require changes in the supply chain.

ENERGY HARVESTERS MARKET POTENTIAL

WIRELESS SENSING FOR AGRICULTURAL MONITORING Precision Agriculture Monitor System (PAMS) is an intelligent system which can monitor the agricultural environments of crops and provides service to farmers. PAMS is based on the wireless sensor network (WSN) technique. EH powered sensors.

WIRELESS SENSING FOR HUMS FOR AIRCRAFTS Positions of sensors required to monitor the health and usage of the Cougar’s Sikorsky S-92. EH powered sensors.

THERMOELECTRIC EH: IN CHIPS Micropelt Thermogenerators http://www.micropelt.com/thermogenerator.php

ENERGY HARVESTERS IN WEARABLES

Thermoelectric watch Perpetual Energy Source

Solar

cell EH

PIEZOELECTRIC EH: CONSUMER APPLICATIONS

Piezo Vibration Sensor

Figure shows an energy harvesting device attached to a pig’s heart. Battery-less pacemaker may eliminate the main shortcoming: wearing out of batteries.

SUMMARY ON MARKET FEASIBILITY STUDIES

1)  EH Technology: Thermoelectric & Piezoelectric are the 2 more ready EH technologies for commercialization.

2)  Market Readiness: dependent on specific application. Can be implemented for wireless sensors applications in the Consumer Electronics sector.

3)  Market Potential: Studies predicts a $2 billion potential by 2024 for just the thermo and piezo-electric EH market.

4)  Sectors with Opportunities: Mainly in wireless sensors, wireless switches, sensors for rotating machines, in HUMS for aircrafts and human healthcare monitoring.






•  Conclusion

AGENDA

CONCLUSION In a SMART WORLD, autonomous smart devices and sensors requires: •  Off-grid power •  Power source that lasts the lifetime of the

device •  Miniaturized and Cheap

Micro-Energy Harvesters satisfy these needs with effective and efficient power management solutions through scaling and materials development towards Nanotechnology.

Business

Energy Harvesting for IoT