Wireless Power Transfer and RF Energy Harvesting: New Options for - PowerPoint PPT Presentation

Wireless Power Transfer and RF Energy Harvesting: New Options for System Designers June 5 , 2 0 1 3 Stanford Com puter System s Colloquium Joshua R. Smith Associate Professor Computer Science and Engineering Electrical Engineering University of Washington

Sensor Systems Lab Graduate Students Current Graduate Students LT Jiang, ME Ben Waters, EE Vamsi Talla, EE Jim Youngquist, CSE Brody Mahony, EE Artem Dementyev, EE Yi “Eve” Zhao, EE Aaron Parks, EE Alumni Alanson Sample Michael Buettner, CSE Lillian Chang (Postdoc) (David Wetherall, co ‐ advisor) (Postdoc) 2 Now Intel Now Google Now Intel

Applications Interpretation Ubicomp Pretouch Grasping Medical Robotics Security Sensor Systems Power Comms WISP Data hiding WARP ABC New sensors WREL FREE ‐ D E ‐ Field Pretouch Seashell Pretouch 3

Why Wireless Power? 4

Benefits of Wireless Power Cord Elimination 5

Benefits of Wireless Power Battery Elimination Lifetime ‐‐‐ Perpetual Size 6 Weight

Benefits of Wireless Power “Monolithic” technology Connector elimination Boundary integrity 7

Benefits of Wireless Power Non ‐ contact energy transfer No Force required to make and break connections…nice in space! 8

The space of wirelessly powered systems Far field Near field Planted WISP WREL FREED Wild WARP ? ABC 9

Energy Efficiency Scaling Energy Efficiency ( I nstr / uJ) Brain 1.0E+ 08 1.0E+ 06 Dell 1.0E+ 04 Instructions per uJ Lattitude E6400 Cray 1 1.0E+ 02 486/ 25 1.0E+ 00 Dell Dimension 2400 1.0E-02 DEC IBM PDP-11/ 20 PC-AT 1.0E-04 1.0E-06 Univac III 1.0E-08 Eniac 1.0E-10 1940 1960 1980 2000 2020 2040 2060 Data: Implications of Historical Trends in the Electrical Efficiency of Computing 1 0 Koomey, Berard, Sanchez et al, IEEE Annals of the History of Computing, 2011

Range scaling of far field WPT 10000000 10000000 Microprocessor Efficiency Friis Distance (Power Limited) Inst/uJ 1000000 Exponential Fit 1000000 Exponential Fit doubling time 100000 100000 Range at which 6 K IPS workload can 2 years be wirelessly powered (Meters) 10000 10000 Swatch EM6682 0.46 t c 2 Instructions per uJoule MSP430 1000 1000 HC08 100 100 f HC05 10 10 0.23 t 8051 d 2 1 1 GI PIC1650 4004 Range 0.1 0.1 doubling time 0.01 0.01 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 4 years Year Range scaling of wirelessly powered sensor systems, J.R. Smith, in Wirelessly Powered Sensor Networks Range scaling of w irelessly pow ered sensor system s and Computational RFID J.R. Smith Ed., Springer 2013 1 1 J.R. Smith, in Wirelessly Powered Sensor Networks and Computational RFID Development and Application of Wirelessly Powered Sensor Node , D. J. Yeager, UW MS Thesis J.R. Smith Ed., Springer 2013

WISP & UHF RFID Tag RFID reader ant Tag Power & data (“downlink”) Data (“uplink”) Backscatter 12

WISP 3 Axis x 10 Bit Accelerometer First UHF ‐ powered accelerometer A wirelessly powered platform for sensing and computation, J.R. Smith, A. Sample, P. Powledge, A. Mamishev, S. Roy. Ubicomp 2006 RFID Sensor Networks with the Intel WISP Winner Best Demo, Sensys 08, M. Buettner, B. 1 3 Greenstein, R. Prasad, A. Sample, J.R. Smith, D. Yeager, D. Wetherall.

WISP Block Diagram Design of an RFID ‐ Based Battery ‐ Free Programmable Sensing Platform, Alanson P. Sample, Daniel J. Yeager, Pauline S. Powledge, Alexander V. Mamishev, Joshua R. Smith. IEEE Transactions on Instrumentation and Measurement, Vol. 57, No. 11, Nov. 2008, pp. 2608 ‐ 2615. 1 4

Analog Front End Vreg + Received Data LS - Received Data Enable Demodulator Power Management Wake Up Stored Voltage Vreg Voltage Voltage Supervisor Regulator POR = 1.6v (1.9v) (1.8v) RF input 1 5

Rectifying Charge Pump (1 stage) RF Rectifier 1 6

Rectifying Charge Pump (3 Stage) 1 7

Rectifier Efficiency Input and output impedance dependent Rectification Efficiency at 1.9 V Output 35 30 25 Efficiency 20 15 10 5 0 0 0.5 1 1.5 2 2.5 Input Power (mW) 1 8

Power Management Block 1.8v REG 1.6v POR 1.9v Wake Up 1 9

WISP Applications 2 0

WISP for Physical Oceanography in the The NEMO/Antares Neutrino Telescope Luciano Trasatti, INFN, Italy PORFIDO: An application of RFID to Oceanography, Trasatti, Cordelli, Habel, Martini, in Wirelessly Powered Sensor Networks and Computational RFID, J.R. Smith Ed., Springer 2013 2 1

Capacitive Touch WISP A Capacitive Touch Interface for Passive RFID Tags, IEEE RFID 2009, Alanson P. Sample, Daniel J. 2 2 Yeager, Joshua R. Smith, Winner, Best Paper Award

EEGWISP A Wearable UHF RFID ‐ Based EEG System , Artem Dementyev and Joshua R. Smith, Proceedings of 2 3 IEEE RFID, Orlando, Florida, April 2013.

RFID Cryptography Strong RFID encryption (RC5) Maximalist Cryptography and Computation on the WISP UHF RFID Tag , In Wirelessly Powered 2 4 Sensor Networks and Computational RFID, J.R. Smith Ed., Springer 2013

Commercialization: Intel BTAG 2 5

Ultrasonic Localization WISP ‐‐‐ ISTC Distribution of one detected tag A battery ‐ free RFID ‐ based indoor acoustic localization platform, Yi Zhao and Joshua R. Smith, 2 6 IEEE RFID, Orlando, Florida, April 2013.

Wirelessly powered bistable display Wirelessly Powered Bistable Display Tags, A. Dementyev, A. Parks, J. Gummeson, D. Ganesan, J.R. Smith, A.P. Sample, To Appear, Ubicomp 2013 2 7

WISP 5.0 ‐‐‐ Available soon WISP 4.1 WISP 5.0 4.3 meters range 9+ meters range* Single antenna Dual antennas 3D accelerometer 3D accelerometer MSP430 ‐ F2272 MSP430 ‐ F5010 • 16 MHz (max), 4MHz @ 1.8v • 25 MHz (max), 8MHz @ 1.8v • 512B RAM • 6,144B Ram • 16K Flash • 16k Flash • Off Mode (LPM4) ‐ 0.1 µA • Off Mode (LPM4) ‐ 1.1 µA • ADC / Timers / UART • ADC / Timers / UART

Analog Backscatter 2 9

Hybrid analog ‐ digital backscatter audio sensing The Great Seal Bug aka “The Thing”, 1945 Hybrid Analog ‐ Digital Zero ‐ Power Mic, 2013 Hybrid Analog ‐ Digital Backscatter: A New Approach for Battery ‐ Free Sensing , V. Talla, J.R. Smith, IEEE RFID 2013. Nominated for best paper award 3 0 Hybrid Analog ‐ Digital Backscatter Platform for High Data Rate, Battery ‐ Free Sensing , V. Talla, M. Buettner, D. Wetherall, J.R. Smith, WiSNET 2013 Winner best student paper award!

3 1 7 m Results 0 .7 m

WARP: Wireless Ambient Radio Power 3 2

WARP: Wireless Ambient Radio Power Experimental results with two wireless power transfer systems, A.P. Sample and J.R. Smith, Proceedings 3 3 RAWCON 2009

WARP: Cell Tower Power Mobile phone base transceiver station (BTS): 2.5 W to 640 W Maximum observed operating range > 200m Each event is 275uJ Harvested ~ 1 ‐ 3uW net Test locations around Experimental rig Mary Gates Hall cell tower A Wireless Sensing Platform Utilizing Ambient RF Energy , Aaron Parks, Alanson Sample, Yi Zhao, 3 4 Joshua R. Smith, WiSNET 2013

Old and new harvester designs Old Harvester ( Type 1 ) Efficient at “high” incident RF power -9 dBm sensitivity ( 1 2 5 uW ) New Harvester ( Type 2 ) High sensitivity, at the expense of efficiency -1 8 dBm sensitivity ( 1 5 .8 uW , alm ost 3 x range im provem ent) 3 5

Old and new harvester designs Old Harvester ( Type 1 ) Startup time 100 Seconds Type 1 10 Type 2 1 10k 20k Activity rate 1 Hz 0.1 New Harvester ( Type 2 ) 0.01 10k 20k Efficiency with duty cycling 60 % 40 20 10k 20k Equivalent free space distance from 1MW TX (m) 3 6

ABC: Ambient Backscatter Communication 3 7

ABC: Ambient Backscatter Communication WISP (backscatter) x WARP (ambient RF) Or, “RFID with no RFID reader” Ambient Backscatter: Wireless Communication out of Thin Air, Vincent Liu, Aaron Parks, Vamsi Talla, 3 8 Shyam Gollakota, David Wetherall, Joshua R. Smith, To appear, SIGCOMM 2013

ABC: Ambient Backscatter Communication Indoor test app Tags able to detect improper order Outdoor ‐‐‐ Fully ambient! within 30s of applying the RF source 100 bps achieved Ambient Backscatter: Wireless Communication out of Thin Air, Vincent Liu, Aaron Parks, Vamsi Talla, 3 9 Shyam Gollakota, David Wetherall, Joshua R. Smith, To appear, SIGCOMM 2013

Demonstrated RF powered, battery free Environmental Sensing Temperature [NEMO] Input devices Accelerometer [WISP] Touch Sensing [Capacitive touch WISP] EEG [EEG WISP] ` Microphones [Analog Backscatter] Cryptography RC5 [WISP], AES [BTAG] Location systems cm ‐ precision, non ‐ camera [ULTRASOUND WISP] Displays NFC ‐ WISP E ‐ Ink display Peer to peer communication 4 0 “Readerless RFID” [ABC]

WREL: Wireless Resonant Energy Link 4 1

WREL: Wireless Resonant Energy Link 60W transferred ~3 feet, +75% efficiency 4 2