BIOELECTRIC GENERATION Ariel Autrand Zaoyi Chi Diego Garcia
BIO-ELECTRIC GENERATION Ariel Autrand, Zaoyi Chi, Diego Garcia, Justin Havely, Qingkun Liu, Bray Moll, Andrew Mullen, Tim O’Rourke W. L. Gore & Associates
AGENDA Project Description Energy Harvesting Concepts Energy Storage Integrated Electronics Testing & Results W. L. Gore & Associates
PROJECT PROBLEM • Modern pacemakers have a maximum lifespan of 10 years due to the physical limitations of their Lithium-Ion battery • Patients are required to undergo an invasive surgical procedure to replace the pacemaker at least every decade • This project sought to solve this problem W. L. Gore & Associates Pacemaker Implant Location
PROJECT GOAL Fully implantable energy harvesting mechanism for implant charging Must outlast lifespan of standard pacemaker battery Generation must occur entirely inside human body with no external apparatuses W. L. Gore & Associates
REQUIREMENTS & SPECIFICATIONS Customer Requirement Engineering Requirement Specification Justification Testing Method Operation Voltage 2. 8 -3. 6 V Upper: Open Circuit Voltage for pacemaker Lithium-Ion batteries. Lower: Recommended Replacement Voltage. Multimeter (Voltage) Control Max Current >18. 8 µA Multimeter (Current) Power Draw W. L. Gore & Associates Pacing Rate: 70 bpm @ 0. 5 ms Voltage: 3. 6 V (Max) Load Impedance: 150 kΩ (Min) Internal Controller Power draw: 70% Factor of Safety: 1. 3 Simulated Load
REQUIREMENTS & SPECIFICATIONS Customer Requirement Engineering Requirement Specification Justification Testing Method Weight <63 g Max: Weight of First Successful Implanted Pacemaker Scale Min: 75% of Current Pacemaker Max: 75% of First Successful Pacemaker Calipers Size Volume Biocompatibility Masterfile FDA approved N/A Cycle Life >10 Years Current Service Life Cyclical Loading Location Available Power > 10 m. W Pull less than 0. 1% of an organ’s power Literature Review Implant Method Industry Acceptable Method Material W. L. Gore & Associates - - -
ENERGY HARVESTING CONCEPTS The team considered… • Capacitive Charger • Inductive Charger • Subdermal Solar Charger • Enzymatic Biofuel Cells • Inertial Generation • Thermoelectric Generation • Piezoelectric Generation W. L. Gore & Associates Subdermal Solar Charger Thermoelectric Generator Inductive Charger
FINAL HARVESTING CONCEPT Piezoelectric • Electricity that results from mechanical stress that’s applied to certain solid materials • Force applied = power • Most promising of the methods researched Piezoelectric • Polyvinylidene Difluoride (PVDF) was chosen because commercial availability and flexibility W. L. Gore & Associates
IMPLANT LOCATION OPTIONS • Aorta of the heart • Advantages: Close proximity to pacemaker; consistent deflection • Disadvantages: Low deflection Aorta With PVDF • Diaphragm • Advantages: Large surface area for mounting; larger deflection than most internal organs • Disadvantages: Using too much area will inhibit body function Diaphragm • Heart • Advantages: Close proximity to pacemaker; large deflections • Disadvantages: Difficult to mount; can inhibit critical body functions • Elbow • Advantages: Large deflection; unidirectional motion • Disadvantages: Far proximity to pacemaker; inconsistent deflection W. L. Gore & Associates Heart Elbow
IMPLANT LOCATION CHOSEN: ELBOW Simulation Parameters Thickness 110 µm Size W. L. Gore & Associates Simulation Results 12 Efficiency 12% Bends Per Day 1500 Max Bend Angle 110° - - Daily Energy Required 0. 864 J Daily Energy Produced 4. 133 J
FUNCTIONALITY SUMMARY • Piezoelectric patch will be deflected when attached to elbow joint • Regulatory Circuit will harness power generated and regulate it for super capacitor • Super capacitor will supply power for Medtronic Advisa DR MRI Sure. Scan A 2 DR 01 pacemaker Piezoelectric Regulatory Circuit Super Capacitor Pacemaker W. L. Gore & Associates
Piezoelectric Module Design Silver Printed Electrode PVDF Conductive Silver Filled Epoxy Polling Direction Protective Coating 12. 7 mm 25. 4 mm W. L. Gore & Associates
MANUFACTURING Manufacturing Procedure: 1. Measure and cut out two pieces of PVDF film 2. Use Xylene and a rag to remove the silver electrode around the border of the film. 3. Mix and apply a thin film of silver filled epoxy and mount the two layers together in a bimorph configuration 4. Attach wire leads 5. Encase in a protective laminate Piezoelectric Manufacturing Process, Steps 1 -5 W. L. Gore & Associates
CIRCUITRY DESIGN • Two comparable circuits manufactured for testing Piezoelectric Source W. L. Gore & Associates Rectifier Voltage Limiter Energy Storage Voltage Regulator Pacemaker
CIRCUITRY DESIGN 32 mm Printed Circuit Board 50 mm W. L. Gore & Associates
CIRCUITRY DESIGN Piezoelectri c source Red LED shows charging state Bit state controlled output Capacitors stabilize irregular input piezo wave W. L. Gore & Associates IC control chip Capacitors use to smooth ripple voltage Super capacitor stores energy
CIRCUITRY DESIGN 30 mm Printed Circuit Board 40 mm W. L. Gore & Associates
TESTING • PVDF piezoelectric energy harvester was mounted to elbow bend simulator • Potentiometer was used to set revolution speed • With harvesting module attached to harvesting circuit and circuit attached to Arduino module, motor was turned on • Data was collected and observed from Arduino display and stopped once target power requirements were fulfilled W. L. Gore & Associates PVDF Mount Location
TESTING Block Diagram W. L. Gore & Associates Voltage Across a 1µF Capacitor vs time at aproximatly 100 bends per minute. Each horizontal division is 20 seconds, and each vertical division is 100 m. V
RESULTS Customer Requirement Power Engineering Requirement Specification Measured Value Operation Voltage 2. 8 -3. 6 V 3. 4 V Pass Control Max Current >18. 8 µA 1. 2 m. A Pass 5. 7 n. W Fail Power Draw W. L. Gore & Associates Pass/Fail
RESULTS Customer Requirement Engineering Requirement Specification Measured Value Weight <63 g 15 g Pass/ Fail Pass Size Volume Pass Biocompatibility Masterfile - Fail Cycle Life >10 Years - TBD Location Available Power > 10 m. W Implant Method Industry Acceptable Method Material W. L. Gore & Associates - 67 W Pass - TBD
Future Development • Use the developed simulated elbow to iterate on the PVDF manufacturing process • Identify the factors causing the large discrepancy between theoretical and actual results • First iteration is never the last W. L. Gore & Associates
ACKNOWLEDGMENTS We would like to thank the following sponsors and mentors for the support during this capstone project… W. L. Gore & Associates David Trevas Amy Swartz George Aukon W. L. Gore & Associates
QUESTIONS? W. L. Gore & Associates
REFERENCES • [1] Nyulangone. org. (2017). Types of Cardiac Devices. [online] Available at: http: //nyulangone. org/conditions/cardiacdevice-management-in-adults/types [Accessed 27 Sep. 2017]. • [2] Crespi, A. , Somdahl, S. , Schmidt, C. and Skerstad, P. (2002). Evolution of power sources for implantable cardioverter defibrillators. Fuel and Energy Abstracts, [online] 43(3), p. 191. Available at: http: //www. sciencedirect. com/science/article/pii/S 0378775301004992 [Accessed 27 Sep. 2017]. • [3] Kelly, S. and Wyatt, J. (2011). A Power-Efficient Neural Tissue Stimulator With Energy Recovery. IEEE Transactions on Biomedical Circuits and Systems, [online] 5(1), pp. 20 -29. Available at: http: //www. ices. cmu. edu/ndel/Papers/Kelly_TBCAS_2011. pdf A Power-Efficient Neural Tissue Stimulator With Energy Recovery [Accessed 27 Sep. 2017]. [4] A. B. Amar, B. A. Kouki and H. Cao, "Power Approaches for Implantable Medical Devices, " Sensors, vol. 15, no. 1, pp. 28889 -28914, 2015. [5] Johns Hopkins Medicine, "Implantable Device Replacement Procedure, " Johns Hopkins Medicine. [Online]. [Accessed 26 September 2017]. [6] D. Borton, "An implantable wireless neural interface for recording cortical circuit dynamics in moving primates. ", " Journal of neural engineering, vol. 10, no. 2, p. 026010, 2013. [7] Y. Yang, X. J. Wei and J. Liu, "Suitability of a termoelectric power generator for implantable medical electronic devices, " Journal of Physics D: Applied Physics, vol. 40, no. 18, p. 5790, 2007. [8] H. Zhang, X. S. Zhang, X. Cheng, Y. Liu, M. Han, X. Xue, S. Wang, F. Yang, S. A. S, H. Zhang and Z. Xu, "A flexible and implantable piezoelectric generator harvesting energy from the pulsation of ascending aorta: in vitro and in vivo studies, " Nano Energy, vol. 12, no. 1, pp. 296 -304, 2015. [9] M. K. Kim, M. S. Kim, S. Lee, C. Kim and Y. J. Kim, "Wearable thermoelectric generator for harvesting human body heat energy, " IOP Publishing Ltd, UK, 2014. [10] B. Moorthy, C. Baek, J. E. Wang, C. K. Jeong, S. Moon, K. -I. Park, and D. K. Kim, “Piezoelectric energy harvesting from a PMN–PT single nanowire, ” RSC Adv. , vol. 7, no. 1, pp. 260– 265, 2017. • • W. L. Gore & Associates
REFERENCES • [11] Paul Kreczanik, Pascal Venet, Alaa Hijazi, Guy Clerc , “Study of Supercapacitor Aging and Lifetime Estimation according to voltage, temperature, and RMS Current, " IEEE Transactions on Industrial Electronics, vol. 61, no. 9, • [12] "News Trade 12 - Apple Designs Inductive Charging; to Launch New i. Mac", Newstrade 12. com, 2018. [Online]. Available: http: //newstrade 12. com/forex-broker/broker-reviews/Apple-Designs-Inductive-Charging-to-Launch-Newi. Mac/index. aspx? id=23. [Accessed: 18 - Apr- 2018]. pp. 4895 -4902, 2014. • [13] 2018. [Online]. Available: https: //www. researchgate. net/figure/A-schematic-presentation-of-wrapping-of-the-dilatedascending-aorta-a-A-longitudinally_fig 1_284281778. [Accessed: 18 - Apr- 2018]. • [14] "Diaphragm - Anatomy Pictures and Information", Innerbody, 2018. [Online]. Available: http: //www. innerbody. com/image/musc 06. html. [Accessed: 18 - Apr- 2018]. • [15] S. Heart, "Structure and Function of Human Heart - Healthn. Cure. org", Healthn. Cure. org, 2018. [Online]. Available: https: //www. healthncure. org/function-of-heart/. [Accessed: 18 - Apr- 2018]. • [16] "Elbow and Forearm - Reconstructive Orthopedics Center", Reconstructive Orthopedics Center, 2018. [Online]. Available: https: //www. rocmd. com/conditions-treated/elbow-and-forearm-anatomy/. [Accessed: 18 - Apr- 2018]. W. L. Gore & Associates
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