Energy harvesting

Human powered IoT
Mario Dellea
mardi 24 Novembre 2015
mario.dellea@he-arc.ch
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Energy harvesting is the process by
which energy is captured, stored and
managed
https://cnes.fr/fr
Rosetta & Philae on Tchouri
Philae’s activity depends of the energy available
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Wearable and implantable systems
Form factor :
Wearable :
2D (flat & flexible)
Implantable : 3D
-> 1cm2
-> 1mm3
The harvested power is proportional to the size
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Autonomy with thin-film batteries
Average power
demand
10mW
1mW
40x30mm 10mAh 1.5V
(1250mWh/cm2)
Autonomy for
1cm2 battery
Energy harvesting
will improve
autonomy
5 days
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50 days
Main sources available on the human body
• Harvestable average ambient power : about 1
mW
cm 2
• Difficult to predict, except for heartbeat and breath
• Useful for microwatts average power applications
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Vullers_VanSchaijk_IMEC_2009_Micropower_Energy_Harvesting
Human energy harvesting in the past
1770 Abraham-Louis Perrelet (self-winding watch)
1972 Synchronar (solar watch)
1980 Thermatron Bulova (thermoelectric watch)
1997 Autoquartz (self-winding electronic watch)
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Power Demand versus Power Harvested
Power
Power Harvested
Average Power
Harvested
Power
Demand
Time
Average Power Demand A storage element is needed!
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Nanopower Energy & Power Management
Nanopower Energy
Harvester
MPPT
Primary battery
VS
Nanopower
Energy Manager
Storage device
choice is not that
Nanopower
Energy
Storage
SM / CDC
DVS / AVS
AC
simple!
Nanopower Wearable Application
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Energy storage devices
Lower charge/discharge
Longer charging time
Ragone chart
Hybrids
Storage device choice
depend of the application!
Higher charge/discharge
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Shorter charging time
Example 1 : RFID powered flow sensor
Implantable transducer for monitoring the flow of cerebrospinal
fluid for the treatment of hydrocephalus
NFC
antenna
•
•
•
•
•
RFID powered
flow sensor
ultra-thin package
pressure sensor
(valve)
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(battery)
Example 2 : Intraocular pressure sensor
to aid glaucoma patients
Powered by
harvesting light that
enters the eye
through the cornea
1.5mm
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ISSCC 2011
A Cubic-Millimeter Energy-Autonomous Wireless Intraocular Pressure Monitor
D. Blaauw, D. Sylvester, A. Arbor; University of Michigan
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Example 3: Piezoelectric energy harvester
Harvesting mechanical
energy, often needs a quite
complex mechanical system
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Micro Blood Pressure Energy Harvester for Intracardiac Pacemaker; Deterre, Lefeuvre, 2014
Energy Management Controller
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Smart Power Management
Ultra low quiescent regulator
Wake-up function
MPPT
Maximum Power Point Tacking
USB Charger
Ultra low input voltage and power
Coldstart : 0.3V / 3 μW
Operating 0.1V / 1 μW
Ultra low power solution
15 nA on battery in protection mode
125 nA supplying low-power apps
Fast cold-start
Aimed to feed the application before
recharging the battery
Primary Cell Life Time Extension
Flexible interface
SPI or I2C interfaces
Only few passive components
Configuration by E2PROM
Power control
Luxmeter
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EM8500 : the only usable
for wearable applications
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Thank you for your attention !
mario.dellea@he-arc.ch
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