Human power generation in space Rutgers symposium on lunar settlement 6/7/07

1. Human power generation in spaceRutgers symposium on lunar settlement6/7/07 Beth Lewandowski, NASA Glenn Research Center Kenneth Gustafson, Case Western Reserve University Douglas Weber, University of Pittsburgh

2. Authors’ background and interests • Power performance of conditioned muscle • Implantable muscle powered generators for neural prostheses • Interest in external generators • References: • Gustafson KJ, Marinache SM, Egrie GD, Reichenbach SH, Models of metabolic utilization predict limiting conditions for sustained power from conditioned skeletal muscle. Annals of Biomedical Engineering, Vol. 34, No. 5, May 2006, pp. 790 – 798. • Lewandowski BE, Kilgore KL, Gustafson KJ, Design considerations for an implantable, muscle powered piezoelectric system for generating electrical power. Annals of Biomedical Engineering, Vol. 35, No. 4, April 2007, pp. 631 – 641.

3. Introduction • Assuming 40% of a 2000 Calorie/day diet is used for physical activity, • 3.35 MJ of energy/day is used to perform activities. • Approximate mechanical energy performed during some physical activities: • Walking/Running (0.49 J/kg*step) • Stair climbing (1.96 J/kg*step) • Cycling (88.2 J/rev) • Lifting (9.8 J/kg*m) • References: • Starner T., Paradiso J.A., Human generated power for mobile electronics, In Low-power electronics design, Piguet, C. CRC Press, Boca Raton, 2005. • Powers S.K., Howley E.T., Exercise physiology: Theory and application to fitness and performance. McGraw Hill Companies, New York, 2004.

4. Introduction • Humans produce work during their activities on Earth and in space • Sunita Williams ran the 26.2 mile Boston marathon on the ISS treadmill, producing approximately 61 W of mechanical power for 4.4 hours, or 962 kJ of energy. • References: • Starner T., Paradiso J.A., Human generated power for mobile electronics, In Low-power electronics design, Piguet, C. CRC Press, Boca Raton, 2005. • Powers S.K., Howley E.T., Exercise physiology: Theory and application to fitness and performance. McGraw Hill Companies, New York, 2004.

5. Human power generation applications on Earth • Boot generator for soldiers on the battlefield • Power in remote locations • Wearable computers • Mobile electronics • Biomedical sensors • References: • http://www.nal.res.in/isssconf/finalisss/13_SA-13.pdf • http://www.edn.com/article/CA6399099.html • http://www.emagin.com/company/index.php

6. Active vs. passive energy generation • Active – using muscles to produce the work • Hand cranking • Leg cranking • Shaking • Lifting • Pushing/pulling • Passive – scavenging power with no increase in metabolic activity • Heat • Breathing • Joint motion • Locomotion

7. Examples of human powered generators • Pedal generators • Hand crank radios • Shake generators for flashlights • Foot pump • String powered generator • References: • http://www.quakekare.com • http://shop.npr.org • http://www.windstreampower.com/ • http://www.freeplayenergy.com • http://www.olpcnews.com/hardware/power_supply/potenco_string_power.html

8. Examples of human powered generators • Heel strike generators in shoes • Inductive backpack • Kinetic motion or thermal powered watch • References: • J. Kymissis, C. Kendall, J. Paradiso, and N. Gershenfeld, "Parasitic power harvesting in shoes," 1998, pp. 132-139. • http://www.dadafootwear,com • L. C. Rome, L. Flynn, E. M. Goldman, and T. D. Yoo, "Generating electricity while walking with loads," Science, vol. 309, no. 5741, pp. 1725-1728, Sept.2005. • http://www.seikowatches.com

9. Examples of human powered generators • Generators within flooring and stairs: • Through use of a matrix of hydraulic compression cushions, where footsteps push fluid through a micro-turbine, generating power that is stored in a super-capacitor. • Gym equipment equipped with generators to capture 50 W of power per person per hour • References: • http://www.the-facility.co.uk/energy_harvesting.php • http://www.inhabitat.com/2007/03/08/human-powered-gyms-in-hong-kong/

10. Advances in energy scavenging technologies • Nanogenerator with zinc oxide fibers • MEMS based microgenerators • Piezoelectric material designed for energy harvesting • Ruggedized, Laminated Piezos (RLP’sTM) • Piezoceramic fiber composites • References: • http://www.sciencedaily.com/releases/2007/04/070405170334.htm • http://www.electronicstalk.com/news/iod/iod130.html • http://www.adaptivenergy.com/ • http://www.advancedcerametrics.com

11. Advances in energy scavenging technologies • Biothermal power source • “Power skin” made from the protein prestin that can produce electrical charges in response to mechanical stresses • References: • http://www.biophan.com/index.php?option=com_content&task=view&id=25&Itemid=119 • http://www.intactlabs.com/

12. Advances in energy scavenging technologies • Better storage methods for energy scavenging • Thin Film Battery • Retains charge, more charge cycles • Hybrid batteries • Combines the best of capacitors and batteries • Microscopic batteries • Matches with MEMS generators • Energy harvesting modules • Adapts to different frequencies and modes of energy harvesting • References: • http://www.infinitepowersolutions.com/ • http://www.lgchem.com/ • http://www.mdatechnology.net/techsearch.asp?articleid=423#sec6 • http://www.aldinc.com/

13. Specific requirements for space • No or reduced gravity in space • Reduces mechanical work done against gravity (W = mgh) • Astronaut fatigue a concern • EVAs are fatiguing, do not want to increase metabolic expenditure by requiring them to operate a generator • Only energy scavenging appropriate in this case • Exception is exercise • Vigorous exercise is prescribed to counteract bone loss, muscle atrophy, prevent cardiac deconditioning, promote mental health • Exercise equipment is well suited for incorporating a power generator • Load applied that approaches 1 g levels • References: • J. C. Buckey, Space Physiology. New York: Oxford University Press, Inc., 2006.

14. Power needs and power produced • Example order of magnitude power needs during a mission • CEV vehicle power – 10 kW • EVA suit – 100 W • PDAs, Laptops – W • Sensors – mW • Example order of magnitude mechanical power produced by humans during activities • Breathing - mW • Touching - mW • Heat – W • Hand cranking - W • Lifting – 10 W • Walking/Running – 10 – 100 W • Pedaling – 100 W • References: • Starner T., Paradiso J.A., Human generated power for mobile electronics, In Low-power electronics design, Piguet, C. CRC Press, Boca Raton, 2005. • Powers S.K., Howley E.T., Exercise physiology: Theory and application to fitness and performance. McGraw Hill Companies, New York, 2004.

15. Possible niche applications of human power generation in space • Charge a laptop or PDA while exercising • Communications equipment • Charge a video player while exercising for a more pleasant experience • Something that might be excluded due to power budget • Biomedical monitoring devices to eliminate batteries in that device

16. Ideas of human power generators for use in space • Piezoelectric chest band generator • Incorporated into ECG monitoring • Exercise equipment • Electromagnetic generator incorporated into • Cycle ergometer • Treadmill rollers

17. Conclusion • There is power available from humans • Through energy dissipation • Through activities • There are methods available for energy harvesting • During the design phase of new space craft and a lunar base there are opportunities to incorporate it into practice • There may be advantages to using human power over traditional methods in niche applications • Provide backup/redundancy/emergency power • Decrease battery recharge/replacement time • Allow for extras not possible due to power budget

18. Acknowledgements • Max Donelan, Simon Fraser University • Bryan Palaszewski, NASA Glenn Research Center • Thomas Kerslake, NASA Glenn Research Center • Robert Cataldo, NASA Glenn Research Center • Homer Fincannon, NASA Glenn Research Center • Ron Colantonio, NASA Glenn Research Center • The NASA Glenn Research Center’s Space Processes & Experiments Division and the NASA Glenn Advanced Capabilities Office

19. Questions?